11v. or 9v.?

[GHOST514]

Hello guys, I got a tech question for you. Can I use a 11v. battery on a gun that I usually use 9v. ? Are there any improuvements on the gun performances? Should I think about upgrading gear box, or motor if I think of using a 11v. battery? Thank you.

[JonsM4]

The higher the voltage the higher your ROF will be. But you don't want your voltage high because you'll destroy your internals.

[THe_Silencer]

Trigger response and rate of fire will improve drastically. I personally can't go back to lower voltage batteries. Upgrading to a MOSFET is a must with an 11.1v and you must keep in mind that there will be much more stress and wear on your internals.

[Strelok]

Keep in mind, most guns are built to run off of an 8.4v. If you stick an 11 in there, it'll be to a similar effect of putting jet engine in a Neon car.

[ThunderCactus]

an 11.1v lipo is also significantly more powerful than an equivalent 10.8v NiMH, because a lipo offers all the amperage your motor needs.
Highly recommend installing a MOSFET switch and upgrading your wiring to increase ROF and battery efficiency before upgrading to lipo.

[phloudernow]

I thought 11.1 was equivalent to a 12V NiMH, anyway as everyone said, usually you would have to upgrade your internals with better quality parts or whatnot in order to run 11.1v lipos.

if you want ROF, a good way to let your gun last longer would be to short stroking your piston, so it gives you higher ROF as well as letting your gun last longer while using an 11.1

either way having a mosfet even a basic one (Nothing fancy needed like a AWS Raptor) allows you to control the discharge rate (correct me if I'm wrong guys i know its something similar) thus allowing your internals to last longer

[Azathoth]

Originally Posted by phloudernow

I thought 11.1 was equivalent to a 12V NiMH, anyway as everyone said, usually you would have to upgrade your internals with better quality parts or whatnot in order to run 11.1v lipos.

if you want ROF, a good way to let your gun last longer would be to short stroking your piston, so it gives you higher ROF as well as letting your gun last longer while using an 11.1

either way having a mosfet even a basic one (Nothing fancy needed like a AWS Raptor) allows you to control the discharge rate (correct me if I'm wrong guys i know its something similar) thus allowing your internals to last longer

I would say that a 12v Nickel battery is closer to performance of a 11.1 lipo than a 10.8v is.

Short strokeing your piston, AND then adding LIPo is effectively increasing your ROF twice over. I do not see how short stroking your piston will increase the longevity of your components, especially that if you are short stroking you are losing so much power from your spring that you need to move up to a m150+ to get the 420fps that players feel is necessary to be competitive.

I Feel that a basic MOSFET is a mandatory upgrade if you are using Large type batteries 9.6v or LiPo. A simple MOSFET is essentially a electronic switch, If you want to have power control to the motor you need to move up to advanced MOSFETS like the trigger master which ramp down the power to the motor after a trigger pull. (Motor power demands are highest in the initial start up sequence to overcome inertia of a static gear train.)

Their is a whole other pile of things you will "need" (read should upgrade) to do if you are running a complex trigger computer such as turning OFF active breaking with high power motors perhaps lathing your comm on the motor, and adjusting the springs on your brushes to reduce arcing, wiring upgrades to the lowest guage possible (silver wire, teflon jacket)



To answer the OP question.

It really depends on the gun. If you are working off a factory made gun that is unmodified and talking about a quality brand then you could run 11.1 without and big issues other than electrical damage from arcing and overloading wires, and increased wear and tear due to high RoF.

[ThunderCactus]

10.8 is mathematically closer to 11.1 than 12.0
My point was for the same voltage, a lipo will provide a higher ROF

[MaciekA]

You will likely not be able to run a 11.1 in the gun without failure unless you upgrade and/or re-adjust almost every critical part of your gearbox, and some parts outside of it (i.e. connectors). It's not hard, but it is tedious if you're doing it for the first time. You will need to do a bit of work and be prepared to make a few mistakes along the way.

Partial checklist...

1. Shimming must be near perfect with absolutely no play or bad interaction, sector, spur, bevel and most importantly the motor's pinion gear.

2. Angle of engagement will likely have to be adjusted to have flat face-on-face contact between the sector's first tooth and the first tooth on your piston.

3. You will have to ensure you're using a decent piston. Ask around, there are tons of options here. SHS blue ain't bad.

4. You will have to ensure you're not using crap gears. Stock gears can range from great to crap, even in high end guns. If you're running a G&P with stock you will want to either be a shimming and AoE hero or replace the gears with gears that won't snap their shafts under the stress.

5. You will need to install a MOSFET to reduce the amount of current over your trigger contacts.

6. A new motor is not necessary but some motors are better at handling the increased power than others without excess heat (look for neodymium magnets, also some of the other guys in this thread know a lot about good motors).

7. You will want to make sure your compression parts are up to snuff. If your compression isn't perfect and you develop a BB jam with back-pressure, prepare to shred a piston in mere seconds or worse.

8. You will want to upgrade your wiring while installing your MOSFET. Two options here are Deans or XT60. I've had good experiences with both.

9. You will want to get good 11.1V LiPos with fat discharge rates. Don't build a monster with a big fat 11.1V feeding tube only to pour a trickle of charge into it. Go for a high C rating. Hobby King will sell you a fairly massive LiPo with a giant discharge rate for the cheapest prices around.

10. If your setup is going to end up being high RoF, high fps, or both, you might want to look into getting nicer bushings. A lot of stock ones aren't that awesome.

[vink]

Two things you have to understand about batteries and lipos especially. NiMh batteries suffer from severe voltage drops, where as lipos don't. A 9.6V drops to approximately 8.4v under load. A 10.8 usually drops to about 9.6v under load. Lipos don't suffer such drastic voltage drops and also has a very flat discharge rate. Also the rated charge on lipos are the average voltages and not the nominal voltages. A 11.1V lipo fully charges to 12.6V. A 7.4V lipo charges up to 8.4V. Because the lipos don't drop voltage as badly as NiMH batteries, the 11.1V lipos are closer to 12V NiMh. The 7.4V lipos are closer to 9.6V NiMH batteries.

[Azathoth]

Originally Posted by vink

Two things you have to understand about batteries and lipos especially. NiMh batteries suffer from severe voltage drops, where as lipos don't. A 9.6V drops to approximately 8.4v under load. A 10.8 usually drops to about 9.6v under load. Lipos don't suffer such drastic voltage drops and also has a very flat discharge rate. Also the rated charge on lipos are the average voltages and not the nominal voltages. A 11.1V lipo fully charges to 12.6V. A 7.4V lipo charges up to 8.4V. Because the lipos don't drop voltage as badly as NiMH batteries, the 11.1V lipos are closer to 12V NiMh. The 7.4V lipos are closer to 9.6V NiMH batteries.

Thank you Vink. I forgot about that, A fully charged LiPO cell is around 4.2v

One more thing to add is that it is very easy to find quality RC lipo's that are very affordable; even cheap when compared to nickel batteries

[phloudernow]

If I'm not wrong, and from personal experience, a Lipo with a high discharge rate (anything above 25c) will fry your trigger contacts easily due to the large current running through.

I ran a 11.1 with a 30c discharge rate, and i think my trigger contacts fried within a few hundred rounds.

Stick to 15c and 20C batteries

[ThunderCactus]

that has nothing to do with discharge rate, it has to do with the voltage of your lipo, and the draw of your motor.
Higher voltage starts that arc at a further distance away, and higher amperage increases the heat generated.
A lipo's chemistry provides all the amperage a motor needs, a NiMH does not, that's why an 11.1v lipo provides higher ROF than a 10.8v NiMH.
Lowering the discharge rate is very dangerous, if your motor tries to draw more amperage than your battery can provide, your lipo's gonna light on fire.

Running anything above 9.6v(mini), 8.4v(large), or 7.4v(lipo) is a bad idea on stock trigger contacts.
That's WHY it's highly recommended to install a MOSFET switch BEFORE jumping to an 11.1v lipo.

[Azathoth]

Originally Posted by ThunderCactus

that has nothing to do with discharge rate, it has to do with the voltage of your lipo, and the draw of your motor.
Higher voltage starts that arc at a further distance away, and higher amperage increases the heat generated.
A lipo's chemistry provides all the amperage a motor needs, a NiMH does not, that's why an 11.1v lipo provides higher ROF than a 10.8v NiMH.
Lowering the discharge rate is very dangerous, if your motor tries to draw more amperage than your battery can provide, your lipo's gonna light on fire.

Running anything above 9.6v(mini), 8.4v(large), or 7.4v(lipo) is a bad idea on stock trigger contacts.
That's WHY it's highly recommended to install a MOSFET switch BEFORE jumping to an 11.1v lipo.

To add some more to the lowering discharge is dangerous...

Lipo's are rated by continuous and "burst" C ratings. Burst being the amount of amps that can be sucked away from the pack for very short periods, depending on the cells that can be up to ~10 seconds but it's typicall around <1 second. Burst ratings tend to be twice the C value and represent the abolute maximum capability of your pack.

To reduce pack stress you don't want to have the lipo discharging at it's maximum rate. a 25c 1100 (25*1.1=27.50 continuous amps) mah battery is just BORDERLINE what is needed to properly run a AEG. I recall reading somewhere on the PTW forum that their electronics and geartrain requires 30amps continuous to operate at peak efficiency. The above pack is typical of buffer lipo's and is just anemic.

I run a 2000mah 50c (Fifty C) Battery pack in my AEG with trigger master and the gun hums quite happily. I haven't opened it since last January and i've used this setup for 2 years with no damage to internals. Previously, when I tried to make my gun look cleaner by using buffer lipo's instead of a battery bag all i got for my trouble was smoking, and puffy lipo packs.

Lowering your discharge is akin to redlining your car engine for 99% of your travel time.

The buffer lipo's especially don't have accurate C ratings on them. If you zip over to hobbyking and find the equivalent pack to the firefox buffer style you will see that the C values are not given in abolutes but estimates between 15-25.

[ThunderCactus]

And that's why I'm probably going to modify a G&P marine stock to use on my PTW lol
Need more sideways lipo room!