Battery FAQ

[techobo]

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?

[Kos-Mos]

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.

[techobo]

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

[pOkiE]

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?

[Scarecrow]

$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.

[Scarecrow]

Originally Posted by ILLusion

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.

^^^^^
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.

[Scarecrow]

Originally Posted by techobo

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?

Originally Posted by Kos-Mos

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.

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.

[Kos-Mos]

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!

[Scarecrow]

Originally Posted by Kos-Mos

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.

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.

[Kos-Mos]

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.

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.*

[Scarecrow]

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.

Originally Posted by Kos-Mos

Yes I know that most people are not using larger cell types and yes I know that heat can deteriorate batteries.

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.

[Kos-Mos]

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.

[Scarecrow]

Originally Posted by Kos-Mos

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.

[Hectic]

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.
_________________________________

[Dr.]

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.