Battery FAQ *Now with more Lithium in it!*
 

I recently searched thru the forums infos on batteries... just to see what is the general knowledge of the community, and geez....

Most of you get a note of 3/10.....


First, a bit of terminology
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MilliAmp/hour (mAh)
Capacity (C)

This term stands for the amount of energy a battery can produce in Amps, during one hour. This also means that if you discharge a 600mAh pack at 1200mA, the pack would most likely last half an hour. The nominal capacity of a pack is usually refered as 1C. For a 600mAh pack, 1C = 600mAh. 3c = 1800mAh and so on. The opposite is also right. If you charge a 1200mAh pack at 2.4A, this means that the pack would be full in about 30 minutes. It also means that the higher this number is, the longer your pack will last. It CANNOT damage your gun if you use extreme high capacity packs. Current is not forced into a gun, the motor only takes what it needs.

The discharge rate is also using "C" as a mesurement unit. This means that a 8.4v 1200mAh mini pack, rated at 10C (most are 10C) can be drained up to 12000mA or 12A.

Volt (v)

This is the unit used to represent the force of a pack or potential. The higher the voltage, the harder the battery want to push electric current out of the pack. It also means that the higher the voltage, the faster your gun's motor will spin, and the higher ROF you will get. Be carefull, as the faster you shot, the harder it is on your gearbox. The internal wires of you motor can also only take som much before it starts to heat-up and melt the insulation around it. It this happens, you motor will get very hot and have a hard time moving your piston. One a motor get's damages, it is not easy to fix. Easiest it to just change it for new one.

Amp (A) or milliAmp (mA)

This is the unit used to reprensent the current. It is the amount of energy in form of electricity that goes thru any electric device. Depending on the type of cell (AA, A, 2/3A, Sub-C) The amount of current that can go tru the pack is different. It is not good to have a pack discharged above it's rate. The pack will get hot quickly, and will eventually wear-out.

AA cells are about 2-3C (2-3 times the capacity of the pack)
A and 2/3A are about 10-15C
Sub-C can be from 20 to 35-40C (the newest packs are 45C, and are expensive, so if you bought your pack 15$, it mostlikely will be 20-25C)
Li-Po pack varie greatly. From 10C to 40C and even 50C (under 20C is no good for airsoft, so a pack under 1500mAh 15C can't be used in your gun unless it is under 300 fps.)

Peak or Delta peak or Fuzzy Logic or anything like that

This is the method used to detect the end of a charging cycle in Ni-Mh and Ni-Cd chemestry. It mesures the voltage of the charging pack. A typical curve will start rising fast, to gradually slow down and finally start to drop. The charger will detect a drop ranging from 5mv for Ni-Mh to 10mv fo Ni-Cd. It will then terminate the charging process.

CC-CV

This is the method used to charge Lithium packs. It first forces constant current in the pack until the voltage rise up to the "normal" level (7.4v for a 2 cells pack or 11.1v for a 3 cells pack). The charger will then only apply constant voltage to the pack and let it take whatever current it needs. The charge will finish when almost no current is drained into the pack.

Cell

This is the name for a single battery. A 8.4v pack is made out of 7 cells, 1.2v each. 7x1.2v = 8.4v
For Li-Po packs, cells are 3.7v each. So a 7.4v pack is made out of 2 cells, and 11.1v is 3 cells.

Type of cell

This is NOT the chemestry. It is the shape of the cell. (AA, 4/5A, 2/3A, Sub-C, etc.)
Li-Po cells are always rectangular. Their dimensions always change depending on capacity. They usually are long and wide, but very thin.

Chemestry

This is the kind of chemicals used in the fabrication of the cell. (Ni-Cd or Ni-Mh or Li-Po)

Ni-Mh : Nickel-Metal hydride
Ni-Cd : Nickel-Cadmium
Li-Po : Lithium-Polymere (full name is Lithium-ion Polymere)


General battery maintenance.
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These actions are good to be followed for both Ni-Mh and Ni-Cd cells.
Li-Po packs have specific maintenance, so please refer to the right section of this post.

-NEVER short a battery pack! This is the best way to have it explode.
-Never charge a pack above the "safe" charging current for it's type.
-Cycling is good for your battery, if not abused. Ni-Cd or Ni-Mh benefit from a cycle discharge, but you ust be carefull as they are not to be discharged the same way, nor at the same frequency.
-Never charge a battery with a charger not designed for it's chemestry, or charging at the wrong voltage. A 8.4v charger is driving around 9.8v, just like a 9.6v is around 11v. Doing it will reduce the life of your pack by a lot, but the pack can also explode, causing damage to surrounding areas.
-It is normal for a pack to become hot. To know if a pack is too hot when charging or discharging (in the gun or on a discharger), simply have it on the inside of your forearm. If you can hold it there for 10 seconds, then it is alright. Some of you already know it, battery work better when hot but not TOO hot. Ask those who got a juice shortage in a winter game....


Ni-Cd vs Ni-Mh
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This is based on both really experience and theory. Give or take, I don't really care. Just don't start arguing as this is not the point of this post. I am writing this to help those that need it.
In most cases a Ni-Mh pack will outclass a Ni-Cd pack by a lot. In some extreme cold conditions, It may seem that Ni-Cd packs are working better. This is due to the difference in chemistry. Try to wrap you Ni-Mh pack in some wool...(No joke) If you can keep the temperature of the pack above -10°c, it will still outperfom any Ni-Cd pack.

Li-Po
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*Li-Po pack are fragile. Handle with care, and never let the pack get hit directly. One good thing to do is to wrap the pack in some foam before have it in the gun.*
*NEVER tape your pack directly, as it could tear the aluminium sleeve when removed.*

Lithium-ion polymere is one of the newest chemestry for batterie. These packs are about twice smaller and lighter than any Ni-Mh pack for the same capacity and can allow a lot more current to flow (Discharge rate). Some packs are rated 10C, and higher grade pack can go up to 30-35C (for a 4000mAh pack, this means the pack can kick 140A out to the motor. Again, the motor will only take what it needs.)
Li-Po packs are charged using a different technique than Ni-CD or Ni-Mh packs. It is called CC-CV, versus delta peak or peak charge. Never plug a Li-Po pack on a Ni-Mh charger. It WILL cause the pack to explode. Li-Po packs take about an hour to charge when empty. NEVER try to charge a Li-Po pack at a higher rate than 1C. For example, a 2000mAh pack must not be charged above 2A. These packs greatly outperform any Ni-Cd or Ni-Mh pack, but must be taken care in a different way.
It is a good thing to place a voltage cut-off between your gun and your Li-Po pack. Li-Po's must not be discharged bellow 3.0v per cell. They will start to deteriorate, and might eventually explode. A little voltage cut-off can be bought for about 10$, an will stop the pack from being overdischarged. If you don't want to use a cut-off, you will need to stop using your gun as soon as ROF start to decrease. This means that voltage is getting low. When your pack looks like it is inflated, it means that it was overdischarged.
Li-Po pack must NEVER GET HOT! If they start to heat-up, this means that the rating is too low for your usage (Drain rate), your pack is empty, it is charged incorrectly or it's life spawn is done. If your pack gets hot, unplug-it right away! Place it in a safe place, where it could not damage anything if it explodes, preferably outside. In normal conditions, the pack will not get hot. If missused, Li-Po pack can explode and cause great damage to material and people. Remember that Lithium is flamable in contact of water, so the humidity in the air makes it burst in fire. The packs are sealed in an aluminium sleeve, so the pack must be broken to explode. If your pack is inflated, this means it as been overdischarged. Dispose of the pack and don't try to use it again.
If you already had your pack heated, check for some gaz bubbles in the pack. These are easy to detect, it will seem as the aluminium sleeve it not attached to the internals anymore. Get rid of the pack as soon as you can. Recharging the pack or using it again can make it explode.

Ni-Cd
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The Ni-Cad chemestry is one of the first efficient way to recharge batteries found. It allows the battery to reach a 60-70% efficiency when charging. This means that in theory, to charge a 2000mAh pack in one hour, we would need to charge it at 3000mAh. It is theory and might not be the best thing to do, depending on the type of cell.
It is good to discharge this type of cell every 2-3 charge. You SHOULD NOT discharge it EVERYTIME you charge it, as it will only shorten it's life. It will not develop the memory problem in a short period of time. This problem can apear after 10-15 consecutives charges without any discharge. It will seem that the pack is of lesser capacity than it should. IT IS NOT ABSOLUTE AND CAN BE REVERSED. You just need to deep cycle it using a good charger.
Even if it is good to discharge a pack, you should never discharge it bellow .09v per cell. Even if it is Ni-Cd, doing so can reverse the voltage of the cell and THIS IS IRREVERSIBLE, as the battery chemicals start to consume themself to keep producing energy.
Discharge current should ALWAYS be bellow 3 times the capacity of the cell. Higher rates can cause damage to the pack because the discharger will detect the low voltage condition too late. A 3000mAh pack should NEVER be discharged above 9A. See the table bellow for best charging/discharging rates for each type of cell.
When you want to store you Ni-Cd pack, you should discharge it first. This will prevent damage to the pack. Don't ask me why, I don't know. I just know that a pack stored fully charged for a whole year will decrease in capacity of about 30%. This is based on my own experiences AND battery fabricant's recommendations.

Ni-Mh
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Ni-Mh chemestry is a recent technology developpement that improve a lot over the older Ni-Mh chemestry cells. It can hold a lot more energy in the same space compared to Ni-Cd. The charging efficiency also has been improved. It vary between 70-85%. Even if the chemestry is not the same, Each cell is still 1.2v, but both the charging and discharging method differ. Again, the type of cell (shape) is the most important factor in determinating the charging current.
The Ni-Mh chemestry allow to charge the battery even when it is not fully discharged. The so called "memory effect" does not exist in these cells. It still is good to cycle the pack in a few conditions. The first one is after you have not used the pack for a while. This is called a "wake-up" cycling. It must be a soft cycle, charging the pack around half of it's capacity and discharging near the capacity (1C).
The other case when it is good to discharge a Ni-Mh pack is after 15-20 charges. The chemicals inside the pack usually want to crystalise. The problem is that bigger the cystals, longer it is to have it react to create energy. It will not decrease capacity. In field condition, you might start to find your gun slow to react, just like when the pack is about to die. This cycling can be done at higher rates, fast charging the pack and fast discharging it. You still must keep the discharging current bellow 3 times the capacity of the pack (3C).
Just like Ni-Cd cells, Ni-Mh cells should not be discharged bellow 0.9v per cell. It is more important for Ni-Mh chemestry as they are slightly more instable, so they will change polarity more easilly (reverse voltage). Just like for Ni-Cd, this is DEFINITIVE.
An other difference between both chemestry is that Ni-Mh pack must be stored partially charged. You must first charge the pack full, then discharge it about 1/4th of it. The reason for that is that batteries will leak energy inside themself, there is nothing we can do about it. The only problem with this is that if the pack is fully discharged, the chemicals will consume themself to cover this energy demand, and will damage the pack in long term.


This mostly is what you must know to get better performances with your battery packs. It is basic knowledge, but still if you don't know...


*Update*
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After a few years, batteries have evolved a little more. Some china manufacturer start marketing "new" types of batteries for airsoft. Not all of them are good.

First is the recent trend to use Li-Po batteries in any and all guns.
I have personally used Li-Po for a few years now in most of my guns. NOT all my guns.
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Since Li-Po packs are only avalaible in 3.7v/cell, this only allows us to use 7.4v and 11.1v packs for our airsoft needs.
Here is the trick:

A good (1500mAh or above, 20C) Li-Po pack of 7.4v will perform better than a 2/3A 8.4v (the standard "mini" pack).
This is because of the drain rate. In this exemple, the LiPo pack can deliver up to 20 times 1.5A. This means that the current that can flow thru the motor is around 30A. The size equivalent Ni-Mh pack (8.4v 1400mAh) is rated only 15C (that is for VERY good quality packs). This means that it can only deliver up to 21A to the motor.
This difference will be visible when the motor starts. Basically, the larger the current flow to the motor, the easier it is to turn it. This makes a difference since the motor will reach it's running speed faster that with the Ni-Mh pack. Even if the voltage of the Ni-Mh pack is higher, since the motor struggle to spin because of the reduced current, it will reach the same speed at a later time. This result in a slugish response in semi-auto and first 3-4 rounds in full auto.
If you have or plan on upgrading your gun above 350fps, the 7.4v pack will have a hard time racking the piston, just like the 8.4v.

This is where the larger 11.1v packs come into play. A 3cells Li-Po pack will have a fully charged voltage around 13v. That is a LOT. But for those running a 400-450fps rifle for summer games, it is the perfect battery.
The reason why it is not a good idea to use a 11.1v in a "stock" or sub-350fps gun is simple: the motor accelerate so fast that the gun will fire 2-3 times even in semi-auto. The gears have some innertia since they are metal, same for the motor's rotor. When using a weak spring, this means that the energy stored in the spinning gears is enought to rack the piston and spring two or three times AFTER the trigger is released.
When at or above 350fps, the spring is stiff enought to break the movement of the gears fast enought to prevent double/triple fire.
The second thing that has to be considered, is that the higher the voltage, the more heat the wires will have to support and the more chance there is that the trigger contacts arc.
So when you upgrade a gun for Li-Po use, it is a good thing to change all the wires for at least 16ga. It might be hard to fit in a V2 mechbox, but it is possible (I did it a few times already).
The trigger unit can also be changed for a "heavy-duty" or similar upgraded unit. Usually, the copper contacts are made thicker, meaning they can take more heat/abuse before getting damaged.
You can also use a high power transistor or MOSFET to re-route the current from the contacts. It effectively boosts the trigger response and completely remove any wear on the contacts. Response is enhanced since the motor-battery circuitry will have a very low resistance compared to the trigger-mosfet circuitry. This means more current will flow with less heat/energy dissipation.

Now if you want to keep it simple, don't use Li-Po. It is the same as when upgrading a gun above 450fps. A lot more parts have to be changed in order to have an efficient and reliable system.
The perfect example would be a 330fps CQB gun. It is too low to use 11.1v, but the ROF would benefit from an incread over the 7.4v/8.4v pack. Best thing to do it to use a 9.6v Ni-Mh pack. It will releive some strain from the mechbox and still give a decent ROF.


The second trend I have found is the use of "Li-ion" packs in stick configuration.
This might seem attractive since you can now fit a larger/higher voltage pack in the space of a stick pack. Great! A Lithium solution for these AKs and MP5s.
Not so much. They are not Li-Po packs, they are Li-ion. Same as these watch batteries.
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I find a lot of these "Firefox 11.1v Lithium battery pack for AK stick" on eBay and other online outlets.
It is a shame that they do not actually give the right informations to customers.

Basically, would you rather run your gun with a flashlight battery of a regular battery?
Li-ion are moslty known as CR123A. They are low current, low capacity batteries that are used in high powered flashlights. CR123A is only one of the shape avalaible (just like AA, 2/3A and Sub-C for Ni-CD and Ni-Mh).

The other little hick, they are NOT 3.7v/cell. Only 3.0v. This means that they are avalaible only in 6v, 9v, and 12v configurations. The "Firefox" ones are then 12v instead of 11.1v.
Also, Li-ion have an energy density very similar to Ni-Mh. This means that is the pack takes the same space as a 1400mAh 8.4v pack, but it is 12v, the actual capacity is somewhere around 900-1000mAh.
Lastly, these are designed to be low-drain cells. They are made to be used for a long period of time, with little current flowing. Best Li-ions that could fit in the space of a 2/3A cell would have only a 10C rating. Not that bad since it is about the same as regular Ni-Mh. Think again. 10 x 1000mAh = 10A. When for Ni-Mh, 10 x 1400mAh = 14A.
The same way a 7.4v pack is better than 8.4v because of the drain rate, a regular 1400mAh 9.6v would outclass a 12v Li-ion pack for AK. Don't be fooled by the "Lithium", these particular packs are not good at all for the use they are intended.

They also require a special charger, not the same as Li-Po packs and not the same as Ni-Cd/Ni-MH packs.


All the AR fans out there must have been looking for a decent solution to using 11.1v LiPo packs with at collapsible stock.
Enter the 11.1v 1200mAh 12C Li-Po, in buffer-tube size!
I had the chance to try theses first hand in two occasions. I must say, these are not that bad for a few uses.
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Every one knows that it is very hard to find a decent battery solution for any AR if not using a full stock or extenal PEQ box. Recently, there has been a lot of these "Firefox" buffer tube packs.
They are Li-Po and 11.1v, 10C or 12C. They fit in most buffer tubes for ARs and they can be found in 3-packs configuration to fit in the handguard.
Now, I had ARs before. A small 9.6v 1400mAh is barely enought for a 400 fps summer gun. And you better have a few spares in case.
The nice thing about these Li-Po is that they can actually fit inside of the "wasted" space of the buffer tube. They also are higher voltage than regular 9.6v packs that can be fitted in the handguard.
They are a tad bit to long to fit in the buffer tube completely. This means that you either have to modify your buffer tube or use a stock that covers the end of it (like a crane or vltor stock).
They are also very low rating (only 10-12C) and they are quite expensive. For the same price as one of these, I can get a 2000mAh 11.1v 20C that fits in the space of a 9.6v mini.
A decent use I found for it was for a 400 fps rifle that was built for my friend. He wanted to use a Magpull CRT stock with a RIS unit and no external battery boxes.
The battery was about 3/4" too long for the stock to collapse completely. We managed to fix this by installing a QD sling point on the buffer tube itself to prevent the stock from accidentaly being closed too much.
Since the battery acces was easy (simply slide the stock off) it didn't really mather that the pack lasted only a few thousands of shot (around 2000). He had 2 packs for day long games.
But since the pack is 11.1v, this means that it is not a good solution for sub-350fps guns. And the wires have to be modified.
I find the discharge rate to be a bit too low for high powered guns however. I never use anything under 20C for airsoft guns. Think about having a pipe bomb right next to you face if for some reason the pack gets over discharged...
It really is a case-by-case thing here. I you are uncertain about Li-Po, this is NOT the right place to start. A crane stock with a good 9.6v 3800mAh+ pack is easier to use and requires less maintenance. It is heavier though.


Finally. Chargers. What is good and what is crap.
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There is a whole lot of chargers on the market, and most of the time this is the part that players skip over, too fast or too cheap.

I will just have a little guide line here as well as some no-go brands/models

This is one of the important part in your airsoft gear, yet everyone I talk to couldn't care less about it.
Most people ask me why I have a 300$ setup just to charge batteries. Believe-it, it is worth the price.

If you plan on using Li-Po packs now or in the future, you want to have a VERY good charger. If you don't want to spent a lot, buy a decent Ni-Mh/Ni-Cd charger and get a Li-Po dedicated charger later.
For Ni-Mh and Ni-Cd, the hot points:
You HAVE to be able to select the charging current. Not only two settings, a decent charger will let you set the current to anything between 500mA to 5000mA.
You HAVE to be able to charge the right cell count. A charger made for 7.2v is NOT good for 8.4v also.
Your charger has to auto-detect the end of charge of the pack. Various names are given to that: Delta-peak, peak-detect, fuzzy logic, delta-v etc. It is does not say, it most likely is not auto-detecting.
-You are looking are a charger around 50-90$ Anything under that will cause you more trouble than anything.
-NEVER shop for a charger in airsoft places. Go to your local hobby shop or hit internet. Avoid used or eBay unless you really know what you are looking for.
www.hobbyking.com
www.greathobbies.com
www.horizonhobby.com
www.towerhobbies.com

For Li-Po, you want all of the above to be included plus you need to have a balancer integrated to the charger. the other solution is to get an "interface" device that allows you to balance the pack WHILE charging.
A good one is made by Electri-fly (worth around 80$ by itself, and you still need a Li-Po charger).
E-Flight, Electri-fly, ThunderPower, Duratrax, Hyperion, Align are good brands for that.
It is a lot easier to find a good one on internet websites.
Be aware that there is more than one standard in the balance plug. Make sure your battery and charger have the same type.

Lastly, the no-go list.

Rule #1: If it is a whole lot cheaper than other brands, it is because it is cheaper. Same as with guns, there is a reason why CA, TM G&P are more expensive than CYMA, DBoy and JG.
Rule #2: "Smart chargers" are not a smart choice. These are amongs the worst chargers I have ever seen. Sure, they cost almost nothing. Ask Long_Bong what that little charger did to his battery in only 1 month. If you think your battery is dying and you use that charger, look no further, you battery IS dead.

*Update 2*

I see a lot of misinformation on the boards since about 3 weeks.

Somehow, people start to think that since 11.1v is a bit too hot, using a LiPo pack that is under-rated will force the current down and thus reduce the damage to the mechbox.

How wrong.

Basic Ohm's law.

I=V/R

I is the current. This is the variable.

V is the voltage applied to the circuit. This is constant (since we are not changing battery as the motor turns or applying a wave form to it).

R is the resistance of the circuit. Unless you change the motor, this one is also constant.

Now let's say we compare a 9.6v 1400mAh 2/3A to a 7.4v 1200mAh 10C. The NiMh 2/3A will have a maximum current rating of 10C also, meaning that both have about the same maximum rating.

Our motor has a resistance of 0.5 Ohms with no load. (quite close to the reality actually).

I = V/R
I = 9.6v/5Ohm
I = 1.92A

This means that the current the motor will try to drain from the 9.6v battery is 1.92A when it is free-spinning.

I = V/R
I = 7.4v/5Ohm
I = 1.48A

The current that the motor will try to drain from the LiPo battery is 1.48A when it is free-spinning.

However, there is also a stall current that defines a motor power consumption and efficiency. Typically, that value is between 15 and 20 times larger than free-spin current.

This means that to start the mechbox, the motor will need around 22-30A for a split second. As soon as the motor start moving, that value drops until the motor reaches maximum speed. If the motor cannot drain enough current from the battery, the acceleration will be delayed.

Electric motors rely on electro-magnetic fields to work. The strengh of a magnetic field is dictated by the CURRENT that flows in the coils. This means that is the motor can drain only 10A and need 20A, it will produce only half the stall torque it could.

An normal NiMh battery will be able to deliver at MOST 15A in a peak, and around 10A continuous.

A normal LiPo (10C) will be able to deliver at MOST 30-35A in a peak and around 12A continuous.

Since stall current is only a fraction of second, the current draw is high for a very short period of time.

Here comes the problem.

We fire in semi-auto. This means that the motor will go in stall at every BB we shoot. On top of it, when firing full auto, each time the spring is released, the motor reaches maximum speed and is then decelerated very fast when the piston re-engages. This causes the magnetic field to be very light when spinning fast, and suddenly it requires to be very strong. Again, higher current drain (not stall current, but at least 5 times the free-spin current).

The way batteries work is not the same for all chemistry.

NiCd and NiMh cells have a very limited current rate. This is caused by the way the chemicals reach inside the battery. Even if needed, the reaction cannot be pushed past a certain point. Pushing it still generates a lot of heat, but since the components are fairly stable, a temperature under 150 degreesF is unlikely to cause an explosion. It will deteriorate the battery however.

LiPo cells are very different. There is two reactions at the same time that produces electricity. One is very active and the other is about the same as the one in NiMh cells. The problem is that the active one will not stop at a certain limit. It can accelerate as long as there is a need for more current.
That reaction generates a lot of heat.
Heat is the problem. The mix of chemicals used in LiPo batteries is a lot more unstable than NiMh of NiCd mix. Heating it releases hydrogen in large quantity. As you may know, hydrogen reacts with oxygen in a violent explosion and generates water. It is also a gas that causes pressure inside the battery. LiPo batteries are made from a Lithium film layed over a polymer core and folded over and over to form a flat roll. This is then wraped in a plastic sleeve, then an aluminum one and plastic again (for protection and insulation). Aluminum is a very brittle metal and is not expandable. This means that the protective sleeve can be damaged by the pressure build-up of the hydrogen.

This is when it can become dangerous:

When the pressure is too high, the sleeve fails and released the hydrogen in the surrounding air. This hydrogen is already very hot and now has plenty of oxygen to react with. The sleeve bursting is making a noise similar to a popped ballon, but is soon followed by a torch-like flame and the noise that comes with it. That flame is around 4000 degreeF or 2200 degreeC. It is hotter than a regular propane torch flame. To give you an idea, glass will melt and evaporate at that temperature.
The hydrogen burning is producing heat and water. Lithium is an alkali metal. It means that it reacts with water. The reaction with water is producing mainly hydrogen and also a lot (I mean a LOT lot) of heat.
This accelerates the burning of hydrogen (and supplies some carburant) and also releases a very toxic substance in vapor from the combustion of the polymer used in the battery. This can be easily be seen when watching videos of LiPo failures online. The white clouds are extremely toxic.

I have been exposed first hand to these vapors and have since some respiratory problems.

Again, please be extremely careful when choosing and using your LiPo battery.

This rocks dude, I vote sticky.

And since I always plug this website, www.batteryuniversity.com

I'd like to have some clarification on the following.
What is deep cycle?
How do you identify the type of cell your pack is using?

On my TLP fuzzy logic charger there is a charge option called "3 Cycles" consisting of :

1. Discharge
2. 2 minutes Slow Charge @ 0.2 A
3. Fast Charging
4. Step 1,2 and 3 repeat 3 times
5. Slow Charge @ 0.2 A
6. End

Is this deep cycle?

yes, that is a deep cycle

You must know a bit about your pack to know witch kind of cell you have...

For example, mini packs (those 600mAh Ni-Cd they sell with the guns) are 2/3AF

AUG packs are 4/5AF cells

Large packs are Sub-C cells

ect..

Here is a list of dimension for each type

AA
Diameter :14.2mm
Height :50mm


2/3 AA
Diameter :14.2mm
Height :29mm


4/5 AA
Diameter :14.2mm
Height :43mm


A
Diameter :17mm
Height :50mm


2/3 A
Diameter :17mm
Height :29mm


4/5 A
Diameter :17mm
Height :43mm


Sub C
Diameter :23mm
Height :43mm


2/3 Sub C
Diameter :23mm
Height :28mm


4/5 Sub C
Diameter :23mm
Height :34mm


4/3 Sub C
Diameter :23mm
Height :50mm


C
Diameter :26mm
Height :46mm


D
Diameter :33mm
Height :60mm


1/2 D
Diameter :33mm
Height :37mm

^^^^What is you measurement unit? Milimeters, inches?
Anyway, thanks for the precision.

those are in " mm "

ok for clarification. i have a tlp charger 4000. i use my battery untill it dies (no longer shoot) then i discharge it with this process EVERYTIME.

on my g36 nimh 9.6 1200mah, and nicd 8.4v 1200mah

on my m4 9.6v 3600mah

is this procedure damaging or degrading my batteries? can you recommend a bettery process?

Well you're basically cutting your usable battery life by 1/3rd. Battery cells have a certain number of charges in its usable life. NiCad I can't remember what it is, but it's around 1700 charges. When you deep cycle, you use up three charges.

Is it possible to have the tread cleaned-up and Sticky? I think it might be of some use to most ppl.

I will add some infos about Li-Po soon too.

*Edit*
Done! Li-Po faqs is now on

Great FAQ, I'm sure I'm not the only one who appreciates the time you must have spent preparing it for the community, but may I make a suggestion? Would it not be beneficial to expand a bit on Amps as it relates directly to the type of cells used? I mean, the reason we cannot run a mechbox from a 7-cell battery consisting of 1.2v, 2200mAh AA cells is because the drain rate (Amps) is not sufficient. (AA cells having a drain current of ~2.1A, and Sub-C cells, for example, having a drain rate of ~30-40A)
It's not a terrible gripe, I'm just trying to distinguish an 8.4v, 2200mAh battery made from AA cells, with an 8.4v, 2200mAh battery made from Sub-C cells for those have less experience with cells, and undermine the importance of cell type. It's your FAQ, and your choice, hahaha, merely wanting to contribute is all. Again, great job, and feel free to use any of this out of context!

thank you!

I hadded some infos on the ratings of cells.

Hey all, just wondering if i could add a link to this thread. Pretty good site with a great battery charge calculator to estimate charge time.

http://www.greenbatteries.com/index.html

Enjoy!

The aluminum sleeve doesn't need to be broken for an explosion to occur. Lithium is quite unstable when heated. Also, if a Lipo battery catches on fire, the lithium creates a very harmful gas. Inhaling this gas will cauterize the internals of the lungs, preventing them from getting oxygen to your blood. Very nasty.

I mean that in normal conditions (About 25°c ambiant temperature, no excessive humidity, no problems in the gun, charger, everything fine) the pack won't burst in flame for no reason. It will burst if you drop it and something tear the aluminium sleeve.

I have an 8.4V 1400mAh 10C Ni-HM

The instructions that came with my charger said that I should use the charging rate of .9A since my battery is within 1100-2100mAh. It says for batteries higher than 2100mAh I should use 1.8A.

Will my battery charge faster if I use 1.8A? Or is that not a good idea in the first place?

Go ahead. You can charge "mini" type batteries up to 2A safely. Actually I charge my 1400mAh at 2.5-3A and they don't get damaged.

My guess is that you have the "Smart universal charger". Yes you can have it at 1.8A no problem.

Ha! That is the charger I have. :) Thanks for the reply.

Do you guys know how well the fairly new Systema Charger works?
link: http://www.redwolfairsoft.com/redwol...l?prodID=20645
It is supposed to automatically determine the amperage and voltage of the battery and charges it accordingly. It also charges 4 batteries consecutively and automatically. From what I read on RedWolf, it works only on Ni-Cd and Ni-Mh, but it seems to be a pretty good set up.

I am fairly new to researching batteries. Where would I be able to buy a Li-Po and charger and exactly how fragile are these things? I have an MC51 with a SBS (SD) type conversion on the front and the battery space is very limited. From what I have read, these batteries are quite a bit smaller for the same output right? I also have an M4 with my battery externally mounted in a pouch on the stock and was thinking that I could place the battery in a small Pelican or Hardigg case before the pouch. Do you think this would be sufficient protection if it were to be shot?

$195USD is pretty steep. I don't find myself needing to charge 4 batteries at the same time but it might be a good investment for a field owner as a service to their customers, or, if you're a complete gun whore like some of the photos I've seen in other threads.

The claim of it being the 'smartest battery charger ever' should be backed up with some technical data so the consumer can make that decision. I've posted all the data on my chargers (http://www.bbbastard.com/nptdetails.htm) so people can make intelligent decisions when they make a purchase. Would be nice to see other retailers follow suit.

Pokie, unless you understand the need for LiPo power regulation, stick with NiCAD or NiMH. Improperly used Lipo's can burst into flames, damage your gun and hurt you if you discharge them wrong.

^^^^^
What he said. Guys, a battery's life is measured in charge/discharge cycles. This means unless you are having overt problems with the battery, stick with an NPT charge system, which minimizes memory issues and conditions the battery as it charges back from whatever level you used it last time. Discharging the battery should only be done for long term storage (3+ months) and even then discharge it to about 1/3 power.

And if you're going to discharge a battery, stay away from those 10amp dischargers. I've even seen some supposedly 'Digital' chargers discharge batteries waaaaaaaay to fast. What is the cheapest and easiest discharger on the market? Simple, a $2 12v backup light from Canadian Tire. Solder a connector to that and use it. Its polarity neutral, and its a more gentle manner to discharge the battery AND the light will indicate when the discharge is complete. I laugh when I see commercial dischargers because they are such a waste of money.

hmmmmmmmm Kos-Mos, you are mostly right - if its a new battery and there is less resistance in the battery, charging a mini at the 2A setting should be okay. Problem is as the battery ages, resistance goes up, and when resistance goes up, faster charging produces heat and gas at higher rates and cause a slow decline in your battery life. Ideally? The mini's *should* be charged at the 0.9A setting, thats what it is for. The large batteries, at the 1.8A (2.0A) setting.

Ultimately? Feel the battery. At the most it should be slightly warm to the touch, preferrably a little less than human skin temperature. Beyond that you're getting into temperatures that produce excess gas in the cells that will separate the materials within the battery, which is ultimately the battery killer.

Slow charging is always preferrable to fast charging so if you have the option (time) to go slow, choose it. I even charge my big batteries at 0.9A unless I am in dire need of it right away (at a game). I've got batteries that are going on their 36 month mark and continue to work fine.

Well...


it is BETTER to discharge a battery as close of it's maximal rating as possible. 10A is actually good for 2/3A cells. Large packs should be discharged around 20-35A, depending on the pack.

It is a lot worst to discharge a pack at, say 1A than not to discharge it at all. Mostly because higher rated cells are able to recover from discharge faster than the actual load, so the pack will be dropped further than at a higher discharge rate.

As for the systemA Charger, I have not tried it yet, but I don't think it would be very good or usefull. That auto charging function, I have tried it on my ICE charger, and I found that the packs where charged a lot less and took a lot more time to be charged.

Plus, you should never leave a pack to be charged unattended (like when you sleep). You never know what can happen, if your pack got hit and have suffered enought damage to burst. (Yes I have seen a Ni-Cd pack explode, it send half a cell 10 feet away with burning acid spit everywhere.)

I agree with Scarecrow on at least one thing, if you have the time to slow charge it, take it. Not because your packs will last longer in lifetime (my 1400's are still packing close to 1600 after over a year of 3A charging), but because the slower you charge, the best run time you will get from it. If you charge your pack at 2A, you will get a little less run from a charge, but you will get a more intense run...(more punch). Slow charge is considered to be between 1/2C-1C. Older packs like the Ni-Cd that come with the stock guns are better been charged at about 400mA, when newer Ni-Mh packs can be slow charged at 1-1.4A. Slower than that is both a was of time and energy.
A slow charge is between 1 to 4 hours.

An other the reason why it is best to discharge the packs close to the maximum rating: Batteries are lazy, if you never ask it to give more than 2A, then i won't be able to give the actual 10A when you need it.

NTP* (Negative pulse) is not a feature used in a lot of chargers. I have it in my 200$ charger, and I almost never use it (it is called reflex charging in my case). The MOST important thing you want to look when shoping a charger is the charge terminaison mode. You need a peak detect or Negative Delta-V detection charger (both are the same, just names). Keep in mind that reflex charging is good but should not be used everytime. It is very usefull to recover old batteries, but it will reduce the effective cycle life of a new pack. It is exactly the same as discharging EVERY time....

For battery temperature, it is always best to keep the pack as cold as possible. But don't panic if your pack gets a bit warmer. A trick I found usefull to check a hot pack is to sit it on the inside of your forearm. If it is too hot to stay there, then the pack is really too hot. This is very subjective, but most people won't stand a temperature above 45°c, which is the approximate maximum a battery should ever reach.

Finally, if you are not sure about what to do with your batteries, stay away from Li-Po. If you think you know exaclty how to react to any situation with Nickel based cells, then do a lot of reseach or PM to have some infos. You need to have the right equipment and be prepared to fetch a good sum if you want to convert from Ni-... to Li-Po.

*Just one last thing, if anyone have anything to add to this FAQ, please send me some PM and we will discuss it. Right now there is more and more contrairy informations stacking in the tread. I tried to keep this as clean and as informative as possible. (One of the reasons I did not mentioned any brand of specific model in the original tread, not to push anyone to buy any charger, as they all have some good points and bad points) Scarecrow, you got mail!

Kos, you're talking about deep cycle batteries. Typical applications such as marine and UPS devices. Generally deep cycle batteries are very large, dense and heavy and many times the size of an airsoft battery. They have more mass which to act as heatsink, and it fact some are designed with heat sink technology built it. Airsoft batteries are chemically similar, BUT, they are by no means like that. They lack the mass to bleed that heat quickly and are not as dense.

You should probably include a provisio on that advice Kos, don't forget not all people are working with C's and D cells, there are a lot of sub-C and the short A stuff and thin material built batteries for things such as Vltor stocks and such. The mini NiMH's I sell fall into that category too. Those kinds of batteries often won't tolerate a 10a load very well for long periods without undue wear on the cells - these batteries are best used for high burst use such as airsoft or RC car racing.

The problem again is easy to detect. Forget the math - if you put your hand on the pack and its too hot to the touch, its TOO MUCH. Excessive heat is your surest sign that your battery is overloading either in charging or in discharging. The heat causes the bonds between the different material to expand and contract at different rates and it breaks the bond which increases the resistance of the battery - this results in faster development of 'memory' and of permanent separation of the substrate materials within the battery itself and thus the life of the battery.

I am not talking about deep cycle batteries, I am talking about normal packs like the ones we are using in our guns (an in my R/C cars). Deep cycle batteries are a catagory of lead based batteries used in marine and other high demand situations. Nickel based cells are made to be discharged almost to the bottom.

I do know that most people are using 2/3A cells and I do know that you can discharge a 2/3A made pack at 10A. I just did it with my 5 packs today (1200mAh Ni-Mh cells, brand GoldPeak, in 7.2v). They did got warm, but not hot. I was a long time I did not discharged them and I have seen the huge difference between before and after cycling. So yes I know what I am talking about. Yes I know that most people are not using larger cell types and yes I know that heat can deteriorate batteries.

Now let's please continue this in PM.

*New version of the FAQ will be put on soon.*

And as I said before, AS long as they don't get hot then thats fine, but I don't think you can universally say putting a 10A load on any battery is a universally safe way to discharge. The pack size and battery size and capacity also play a roll, but heat is an ultimate indicator. If its hot to the touch, you're doing damage, simple as that.

No need to do this through PM, its a perfectly fine conversation to have, and different viewpoints *should* be part of a discussion. What you've said here is precisely why it should be discussed, because most people don't treat their batteries properly.

I've had plenty of returns from people who've foobar'd their batteries doing fast/deep discharge on the advice of others using fancy 4A-10A dischargers but at the wrong settings (ie: 1200mah NiCAD 8.4v packs) "but all I did was use the discharger!!!"

Sometimes I can bring the battery back (its a memory thing) and other times I can't (the chemistry is screwed). So you can do all the fancy Google searching on battery technology you want, bottom line is I've seen what people have done in their returns. I have a computerized digital battery conditioner with a reconditioning charge and discharge function on it. Generally I don't set the discharge above 4A if I am reconditioning a battery, or preparing a new one (yes I prep my batteries because most people don't know how to do that, and thats why everyone thinks there is something magical about BB Bastard batteries...). Its nothing more than cycling them a couple times to get them up to their max capacity. After that the NPT charger prevents them from doing anything overly damaging to the battery and they get good longer term airsoft use out of them.

The reason why I would like this to be in PM is that this is supposed to be a FAQ. Now it turns into a huge mess.... from an exterior point of view.

I don't really mind to argue about what to do or not with batteries, just not in this tread. We could start a separte one if you want, I would just like to keep the FAQ clean.

Just incorporate the feedback into the FAQ in some manner and delete the original posts. I trust you to process it effectively, and I don't have ego about deleted posts to clean up the thread. I think we're both interested in making sure people have the facts, so I think we are on the same page even if we quibble a little.

Peace dude.

out.

Batterie Question
 

I Have An M4A1 Jingg Gongg Has A Mini Batt 8.4v 1100mAh
How do i find out the discharge rate 10 amps or 30?

i have modified the upper hand guard to hold the batterie and was thinling of upgrading to a

#2708NC ATTACK PACK: 9.6v NiMH 2700mah Airsoft Nun-Chuck Battery
Connector: mini Tamiya (Marui)
Cell: Sanyo HRAUX 2700mah A
Pack Size (LxWxH): 4.00"x 1.32"x .66" (each chuck)
Discharge rate: 10amps
Or\
#E3016NC ATTACK PACK: 9.6v NiMH 3000mah Airsoft Nun-Chuck Battery
Connector: mini Tamiya (Marui)
Cell: ELITE 1500MAH 2/3 A
Pack Size (LxWxH): 4.62"x 1.32"x .66" (each chuck)
Discharge rate: 30amps


just dont want to hurt anything does the discharge rate affect anything besides the time the batt will last eg:more amps =less shots i also know that if i upgrade the spring later the 30 amps will be needed to cycle the gears

Thanks in advance for any help.
_________________________________

Just a heads up to Kos-Mos, the 4 links at the end of your first post in this sticky have died (or at least do not work for me).

First 2 (Charge rates) take me to an *unable to view this page* splash screen, second 2 (discharge rates) are pictures of a sword (top and bottom).

Thanks for the great info though!

Cheers,
-Dr.

Dischare at 10 is an heavy load... you should try around 5A

And DISCHARGING as nothing to do with battery capacity at all... it helps maximizing battery life.

Ni-Mh packs don't need to be discharged every time.

And READ the first tread, which is the FAQ.... everything you have just asked is in there.

*get the 3000mAh pack. 2/3A cells have a better discharge capability than A cells

Thank You For The Help I Think Im Gonna Go With This
http://velocityarms.ca/index.php?mai...products_id=33
and this
http://velocityarms.ca/index.php?mai...&products_id=8

Useful resource for calculating charge times:

http://www.greenbatteries.com/batterycalc.html

Thanx 4 the link! :cheers:

-BH

now I have a stupid question that is probably answered here somewhere If I put a 9.6 volt battery in my stock TM mp5 or stock JG M4 to increase ROF will I kill my gearbox or motor much faster than the 8.4 or will it not put much more stress on them.
Thanks!
Norm.

It will chew the stock components up really quick. Do these aeg's have the EG700 or equivalent motor ? If so then just upgrade to an EG1000. If you are persistent on using the 9.6v battery, at least upgrade the gears. If i'm wrong someone please correct me.

that sounds reasonable thanks
and no im not stuck on a 9.6 i just need a small ass batt to fit in a M4 upper handguard with the m203 on the barrel i'm gonna see today if the BB bastard 8.4 is a bit smaller than the stock JG 8.4 that i have now

Does anyone know if the chargers at WGC are compatible with the North American system, or am I going to have to buy an adapter?

You'll probably need an adapter at the very least. The other thing is Asia IIRC uses a 50Hz electrical system, we use a 60Hz. Don't know if that will make a difference, but you'd probably be better off buying a charger in North America.

Even something like this?

http://cgi.ebay.ca/TLP-EXPRO-II-Fuzz...QQcmdZViewItem

I don't know anything about the Hz electrical system, but this says 100-240 AC input. I'm just having trouble finding anything here in Fredericton. There are no hobby shops around...

I can order you one and ship it...

I am manager of a hobby shop.

Anything you want, I can have it.

Not sure if this has been covered before. I'm paralleling two small batteries in a fake ANPEQ. They are identical 8.4 1400mah minis and give me a crazy ROF, comparable to my large 2400 battery (which won't fit in the ANPEQ).

Can I charge them together or should I charge them seperately? I'd prefer leaving them together because I'm lazy, but I believe my TLP charger says its for 4-8 cell batteries while the batteries have 14 combined. Will my blue universal smart charger work better for charging them in parallel?

Thanks.

Charge them separately would be my advice.

You should charge them separately.

A Good parallel system would have all cells paired, then wired in serial, not the opposite.

would this be bad for a krakens gearbox?
http://cgi.ebay.com/ws/eBayISAPI.dll...tchlink:top:us
the only upgrades i have in it is a G&P "explosive" piston head and a set of systema bushings

11 volts, Id say its a little high. It'll give you some crazy rate of fire.
Maybe shred some piston teeth, maybe not. Maybe chew up some gear teeth, maybe not.

sounds like its not worth the risk then. ill just grab a firefox 8.4 1500mah stick instead
i liked the near instant response when pulling the trigger on semi when i tesed my lipoly battery in it

You can ask that kind of question on a new tread, as it does not bring anything to the FAQ.

But yes you coud use it. I am running a 12v (11.1v) in almost all my guns, sofar, the pistons are holding perfectly.

i was more worried about the gears as tokyo said. were talking kraken/cyma stock gears here

Good guide/FAQ. I use a 9.6V 1700 MaH and I get a good rate of fire and it lasts the whole day. If you are looking for a good battery, get one like mine.

Just to make sure, I have a FireFox 11.1V 1600mAh 15C Li-Po battery and a FireFox 12.6V 1A Li-ion Charger. So you're saying that it should be fully charged in an hour? Also, I think I did something really bad because I charged it for about 8 hours for the first time and also used my TM Battery Discharger to discharge it completely after I was done using it. I have not charged the battery since the first time, so should I scrap it and get a new one?

Li-Po's should not be discharged, especially not down to nothing.

Throw it out at a hazardous waste place.

So is the suggested time of charging any Li-Po battery fully is 1 hour? Can I play a full days worth of gaming if I charge it for only 1 hour?

I'd only use a lipo charger WITH auto cut off. Mine takes about an hour, maybe slightly longer but it stops itself. And SHOULD last a full game day... though I haven't gamed with mine yet but i plink allot in my basement and it's lasted many oh days with one charge.

To give my input:

I had a 7.4v 20C 1600mah lipo in my M4 with a Magnum Motor/Hi Torque Gears/380fps spring, and I lasted two 4 hour games at TTAC3, and a 6 hour game at FlagRaiders before charging: Sure, the battery was low, but still above the over discharge limit. I do not run a disconnect circuit, but I suggest that you should, it's less of a safety hazard and more about protecting the battery.

Ni-Cd Charger for Ni-Mh?
 

ok guys I need help here..

I bought an airsoft with a Ni-Cd battery but its cheap so I want to buy a Ni-Mh, the problem is I don't know if my actual charger(black square thing,wall power supply) will be good to charge my Ni-Mh.. I read on the charger but its not written if its a Ni-Cd or Ni-Mh charger.. here what its says:

Class 2 power supply

Model:YXD08402501-18

INPUT: 120V AC 60Hz 90 mA

OUTPUT: 8.4V DC 250mA

C UL US

so do you think it will charge an Ni-Mh battery(same voltage 8.4v)?

That's not really a charger.. just a transformer.

Get the NPT Smart Charger from www.bbbastard.com

The thing is I dont want to spent much more money then I already paid for all my airsoft stuff.. do you think my ''transformer'' can actually charge an Ni-Mh?

ok so with this being said i was wondering that is this: http://shop.ehobbyasia.com/bb-batter...ak-series.html
worth it to buy???

You know the answer. You QUOTED it.

There is over 70 types of lithium batteries. Most are NOT suitable for high discharge use (think watch battery or photo camera battery).

Lithium =/= awesome.

Now stop polluting this thread with questions that HAVE BEEN ANSWERED ALREADY IN THE SAID THREAD!

Updated with more information about LiPos and why use a properly rated battery.

Thank you...that's awesome.

Ebay chargers are good for your money. I have 2 of them and i can tell you, they are worth your 60$ (they can charge ANYTHING)

If you want to use a LiPo but your gun is stock, best is to use a battery which gives discharge rate of 15C and at 7.4V. 7.4V in lipo is equivalent to 9.6V nimh ... 15C will not tear your gearbox and gears apart like an 11.1V , that's why most often, 7.4V 15C batteries priced like an 11.1V 20-35C battery.

No.

Read the update I JUST added.

The reason 15C packs are priced like 25C packs is because it is labeled as "airsoft".

I can get a 1300mAh 15C pack for under 15$ from hobby websites.

http://www.hobbycity.com/hobbycity/s...Ah_3S1P_15-25C

It will never be more gentle on your internals. In fact, it will most likely damage the motor and accelerate the wear on it.

Because if the motor is allowed to accelerate very fast, the current drops almost instantly. Where when you limit it, the motor will drain the maximum for a longer period of time before dropping.

Think about it this way. 35A for 1 second then 5A for 9 seconds or 15A for 5 seconds then 5A for 5 seconds.

If you want to save your internals, do a regular maintenance and adjust your mechbox properly. If you are still unsafe, reduce the voltage of your battery.

I have run STOCK TM guns, except for the bushings and spring at 400 fps on 11.1v LiPo for YEARS. EVERYTHING is holding.

Hey I have a small question.

I just got my charger yesterday, and I was wondering how I should charge the batteries.

I got this charger:
http://www.airsoftparts.ca/store2/in...oducts_id=1030

it can charge at 0.9A or 1.8A.

the battery I am getting is a G&P(yeah I ordered a tamiya to deans adaptor since the charger dont have deans plugs...), 8.4v 2200mAh. Should I charge it on .9 or on 1.8A? also if I undestand the first post correctly, lets say I charge it at .9A, it should take 2.4 hours to charge right? 2200 / 900 = 2.44...

It depends on your battery.

The safe thing to do is to put it on 0.9A setting.

If your pack is made out of AA cells, stick to lower setting. If it is made of 2/3 A or 4/5A, you can put is at 1.8A.

Can you charge lipos with a universal smart NPT charger like the one sold by airsoftparts.ca? Because according to this you just need an additional balancing chip? What are the cons of not balancing the battery?

No

The charger you linked only works for LiPo use.

If you want to blow your house away, feel free to try it though. My one-time experience sent some metal shrapnel into the wall 74' way.

You do hits some very good points in your original post, Kos. I haven't read through the whole 5 pages but I gotta clarify a few inaccuracies in your original post.


1)

Your definitions of energy and power are misleading/inaccurate. You say current is energy and voltage is power. Most people won't even understand the true definitions anyways.


2)

You also state that motors draw as much current as they need, and this isn't totally accurate. We're dealing with DC motors NOT AC motors. AC motors will draw as much current as they need to reach their rated Speed - this is due to AC power being sinusoidal at 60Hz (50Hz in Europe). DC power is not sinusoidal so if you:

- Use the same type of battery cells
- Increase the voltage (ie. add one more cell)
= You'll push MORE current into the AEG DC motor.

Here's some testing done by an airsoft player proving this:
http://www.airsoftcanada.com/showthread.php?t=57571

Note the 1700mah mini battery can only push 9.5 amps. The previous two Sub C packs have similar discharge characteristics and prove my point.

If you look at the "Motor Current Vs Load" graph here ( http://www.girr.org/girr/tips/tips5/motor_tips.html ), it also shows that as you increase voltage (loaded) you'll push slightly more current.

This leads me to the point you make:



3)

Heat is more related to the current flowing through the wires, not the voltage. It's like fluid flowing through a pipe, the faster it flows, the more friction is generated (thus more heat). This is why when you spec wires for a system you generally use the current going through them (http://www.interfacebus.com/Copper_Wire_AWG_SIze.html). Although more voltage does mean more current in our case.

You're bang on with the arcing issue and higher voltages, though.



EDIT: I'm a Mechanical Engineer, BTW, but am trying to unlock the mysteries of electricity for myself. The guys I work with are very helpful.
EDIT2: Forgot a link.

Thank you for your inputs.

I know my explanations are not the most accurate in an engineering point of view, but it I worded them so that the average person understands. I did make a mistake however, as voltage is equivalent to potential, where power is the 2-dimension unit representing the combination of both current and voltage.

In theory, DC motors do not drain an infinite amount of current. Every motor can be tested at a stall load to get the maximum current drained into the system.

That value is way past anything that the components of the AEG can hold for more than a few seconds. For all purposes and intend, the value is too large to be relevent. In this perspective, 100A in a system that can take at most 40A can be considered infinite.

When the system is powered by a battery that can deliver around 40-50A peak, it also can be considered infinite in the way that it is a lot above the physical limit of the components.

You cannot push more current into an electrical system because current is a 1-dimension unit. It represents the instantaneous amount of energy that flows in a device. To be able to "push" more current, it would need to be at least 2-dimensional. Voltage is a speed at which the current is moving, thus it can be "forced" faster into the device. The increase in current is only a side effect of the increase in power with the same load or resistance on the circuit.

Also, when using a microcontrolled MOSFET unit such as the Trigger Master, the signal going to the motor is an AC wave form generated by the PWM signal from the controller amplified by the MOSFET.

**WARNING** this is bound to get nerd'ed up here fast...

Kos, can you reword your above post to reflect which portions of my post you are talking about; I'm having a tough time following you.

Potential IS voltage, not equivalent to. The terms are use interchangeably, potential just makes more 'sense'. For instance, you rub your feet on the carpet and now have a static charge (voltage/potential)...you now have the 'potential' to shock the hell out of someone - assuming the other person is at a lower voltage/potential than you are. I haven't a clue what you mean by "2-dimension unit"...are you talking about scalars vs vectors???

Not sure what you were trying to prove/disprove there.


Again, you lost me there.

It's the amount of Coulombs that flow (not necessarily in a device) -> Amperes = Coulomb / second. Volt x Coulomb = Joule (joules is the unit of energy)

Sorry, but that makes no sense. The mechanical analogy to Voltage is Pressure (ie. PSI, kPa), and current is the fluid flow (ie. GPM, CFM). You can think of an electrical system exactly like a hydraulic system. Mathematically you also model both systems the same way (treat pressure like voltage and current like fluid flow).


Again, not sure what you meant here but I'm going to try and clarify things.

Power = Voltage x Current

Resistance of the system stays the same (ie. you don't upgrade/downgrade your AEG spring or change anything).

Now if you assume your theory that the motor only draws as much current as it NEEDS, then the power consumption would remain constant. So if this were true, if you increased the voltage you would see the current DECREASE to compensate to keep the power constant.

However it's proven that this isn't the case with our DC AEG motors. When you increase the voltage, the current also increases (thus more power). This is why we get higher ROF when we increase the voltage - assuming the cells have similar discharge characteristics.




Think of an AEG electrical system like an air powered angle grinder. If you want the grinder to spin faster, you need more power...so you need more air! To get more air you either:

a) increase the pressure (voltage) or
b) decrease the resistance - like use a larger diameter air hose - so more air (current) can flow.

http://www.horisonhobby.com/

is dead, thanks for all the tips and general FAQ knowledge.

I had a 9.6v 1700mah NiCd, which I did not discharge, sitting away for 2-3 years. It seems to charge fine and is usable once again. However I'm not sure how the capacity held up since I don't usually unload ~1700 rounds.

Typo.

Should read:

http://www.horizonhobby.com

NiCds are ok to be re-used after 2-3 years, but capacity will suffer.

You will probably notice after a few charges that the battery struggle to shoot 500 BBs... that is because it is getting too old.

Say I have a Lipo 11.1v 20c 1300mah, can I tell when it reaches ~3v by counting the rounds fired? Or does it depend on the motor and spring as well?

Best bet is to get a Trigger Master MOSFET with a low batt warning. Counting rounds is only for a very rough ballpark.

I thought total rounds are limited by mah, I guess that's not the case for Lipo? Anyways if his 1500rds only used 1.2v, I think I found my ballpark, until I get the LVC.

StrikeFreedom...I disagree. Your approach is complete bullshit.

Taking someone else's results and taking that for fact is not prudent. You have no idea what gear ratio/motor/spring I had in my gun...you have no idea if I shot semi mostly, or mag long full auto bursts. Both of those factors have a huge impact and the ability of your battery to keep up with that is directly affected by those factors. (or rather...the characteristics of a given battery is tested very differently in those setups).

Saying 1 shot per mAh...don't know about that. If I'm pulling a really stiff spring on a std ration gear with a so-so motor...I'll used up more energy than if I shot a light spring with a decent motor with the same gear set.

If I shoot exclusively semi...I'm making the motor start up to torque/speed with every shot, which will use a lot more power than if I just shot long full auto strings.

If my battery is small (and that one is) it might have decent start up power, but quickly start to lag on full auto with a stiff setup. A large pack might be better in having more than enough juice to start up a motor and sustain long bursts.

So....THE BEST THING TO DO IS:
1. Get a quick decent way to measure your pack...hobby/ebay shops have a little dongle you can plug into the balancing tap and it'll read each cells voltage and the total pack voltage. Takes about 5-10seconds. Check before the game, check periodically when you can, check after you're done for the day.
2. Start with a freshly charged LiPo every game...they don't suffer badly from a "memory effect"...so there's no harm in topping it up if in doubt of it's capacity. Besides...it sucks to start a game and run out of juice. Have a second LiPo ready to go. Number your packs and tag a questionable battery to check out later.
3. Learn the characteristics of your battery, in your gun....how many mags you can get out of it. You'll get this by measuring the pack throughout the game/day.
4. ABSOLUTELY...have a good charger that can sense/display what is going on with your pack and balances it properly. LEARN how to interpret what your charger is telling you.
5. STOP...if your battery seems weak or you ROF starts to slow down. Check your pack...swap it out if necessary.

LiPo's are great. Lots of power in a small package. But if you want to minimize your risks...and maximize the life/usage of them...you've got to understand what's going on when you use it.

Best of luck,

Tys

Yes I made assumptions as I just needed a ballpark. Since it was an outdoor milsim I assume you were running ~400fps with a somewhat torquey motor. I run with <350fps with a high speed motor. So I believe in that aspect my setup draws less power than yours. Of course I could be wrong lol.

I know that semi draws more power than full auto; it's pretty much common sense, similar to gas consumption when driving a car.

I will get a LVC...soon.

If you know your rifle VERY well, and have been using LiPo safely for quite a long time, you can guess when it reaches 3v.

I don't need an electronic sensor because I know exactly when to stop.

You *CAN* get a ROUGH idea of a good time to stop if you have a Ni-MH battery that is the save voltage range (say 8.4v is in the same range as a 7.4 LiPo, 12v is for 11.1v) and same capacity. Take a 15-20% margin to be safe.

If you are using a large pack (3000mAh +), you should be good for at least a complete game. Just charge it every time you are done with it.

If you are restricted in space and are using a smaller one (like the little 1200mAh for buffer tubes), you should consider stopping at about 1000. The pack CAN fire more, but depending on your setup, past 1000 is total random.

When you get used to the gun, you will know when the pack drops. That is because LiPo have a very linear and sharp voltage drop. The gun will fire fine. 5 rounds later it will struggle. You will notice it by sound, feel and response. You HAVE to stop BEFORE it struggles. If you stop RIGHT THERE, there will be no harm to the pack.

3.0v is an average. Some good packs can be dropped a bit lower without harm. Some cheap ones will start to heat-up at 3.3v.

The most important thing is you NEVER want you pack to heat, even less to puff. If your pack start to swell, STOP USING IT. I mean stop using forever.

I ordered those cheap tiny monitor module from eBay, it's on its way.

http://www.sgshoppin.com/store/images/led.jpg

That's the same one I use. Find a little plastic box or something to tuck it into...the you can keep it in a pouch on you at games. Until you feel like you really know your setup...check your battery as often as you can.

Temp, age/#of cycles, etc...all affect how a battery lasts...so check it again periodically later on (or everytime...but I don't do that).

You'll see pretty quick...it ain't rocket science but you do have to think about it.

im going to buy G&G CQB-S but i have problem with battery - i have searched many sites and they recommend Intellect 9.6V 1400mAh for GG CQBR/S Series - it is still "out of stock" on most sites. Some people whitch i asked said sanyo will not fit there /because they are bigger/ - could you recommend me whitch to buy - it looks like GG have little different shape of crane stock?

Check www.cheapbatterypacks.com. They're in the US but they make awesome batteries for good prices, usually takes about a week to get the battery.

http://www.airsoftparts.ca/store2/in...oducts_id=1585

It states that it will specifically fit in a G&G CQBR and CQBS Crane stock

I found out from a friend that a 11.1v 1300mah 20c (26A) has a faster trigger response (semi-auto) than a 11.1v 1100mah 15c (16.5A). Would a 7.4v 1300mah 20c have the same trigger response? So higher the "A" (mah*c) the faster the trigger response, regardless of the 11.1/7.4v? ROF is not an issue.

No

The voltage and drain rate will be the big factor here. If you where to compare a 7.4v 5000mAh 20C to a 11.1v 1300mAh 20c, then yes, there is a huge difference between the two, enough to make a difference.

ROF = Trigger response, so it is an issue. If your gun can fire 13bb/sec, your best response would be 1/13th of a sec. If you gun can fire 24 bb/sec, then your best response is 1/24th.

Found a site with lots of FAQ answers on NiCad and NiMH chargers and batteries.

http://www.greenbatteries.com/bachfa.html

* What's the difference between a rapid charger and a fast charger?
* Does rapid charging reduce the life of batteries?
* How long will it take a charger to charge batteries?
* Can a battery charger damage a battery (shorten its life or reduce its capacity)?
* What is trickle charge?
* Is trickle charging harmful?
* What's the difference between a NiMH battery charger and a NiCd battery charger?
* Can I use an older NiCd battery charger to charge NiMH batteries?
* Which are better, NiCD or NiMH batteries?
* What is battery conditioning or exercising?
* What is a charge channel or charge circuit?
* What is a charge station?
* What makes a charger a "smart charger"?

So... I bought a 2200mah 11.1v nano from hobbyking, and it says not to exceed 10C for charging (45C-90C max discharge). I was wondering... people are saying don't exceed 1C for charging, so that would mean 2.2A, but at 10C, wouldn't that mean I could charge at 22A?

I have gotten burned by buying imax b6 chargers off ebay, which I believe were fakes. I briefly read over this thread - for someone who wants to charge both lipos and nimh batteries, does anyone have a link to a reputable charger in the $50-$100 range? Thank you in advance.

Been ages since I wrote that, but right now the ISDT Q6 Pro is the one to get.

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