7.4v Firefox Lipo issues

I bought a firefox 7.4 lipo, and a firefox balance charger and its got me frustrated. I plugged the batt. up and 2 lights came on, when 2 lights when off i plugged my volt alarm into it and it didnt beep, so the next day i tried to test it out and when i plugged it in nothing happened, so that night i went back home, plugged the volt alram in and it didnt beep, so i plugged it into the charger and the lights didnt come on, so after leaving it plugged in for about 2 hours ( because i assumed the lights just meant it was balancing and when it was charged maybe the lights would turn green, yes I had to guess because the manual on the package is in chinese) i plugged it back into the gun and it fired just fine. 3 days later i tried to shoot it again and plugged it in and nothing happened! Took it home and plugged it up to the charger and the 2 lights came on for about 3 seconds then went off! Checked it with a voltmeter and it showed 8.2 volts DC, but wont work on any of my guns.

Whats driving me crazy is i did all that with my 11.1, volt tested it before charging and it beeped, plugged it into the charger and 3 lights came on about 2 hours later they went off, volt tested it and no beep, plugged it into the gun 3 days later and it worked just fine.

Any suggestions??

Learn to read Chinese... Sorry, that is all I got!

Im not familiar with that charger, and all I searched came up with guys asking the same question as you and getting no answer.

Its a $20 charger. I doubt if it is really correctly balancing anyway. I suspect It has an autodetect that will not charge out of balance batterys. Or it will (slowly, very slowly) balance out of whack cells to a point that the battery will charge.
I bet your 2 cell battery is bad. Especially if it is showing 8.2 and wont work. 8.4 is max charge.

Im sorry to have to say, but if you plan on sticking with lipo...and everyone should. You need to get a charger with a led screen and separate balance and power leads. These show you each cell and can charge at much higher amps. You need to know how many Mah you have put in and whatnot.But they are expensive.
I dont know much about any mid-range price chargers..mine was $140
Im sure there are some way under a hundred that are not as powereful, ect.
You probably dont need or want to charge at 5+ amps...
Rule of thumb is charge at 1 amp per 1000MaH the battery has---if its a 3200, charge it at 3.2 amps...an 1800 MaH can take 1.8 amp charge. You CAN go higer..in a pinch, but it can degrade battery life and risk fire.

Hope that helps some.

Yeah it was like 12 bucks from HK so i dont put alot of stock in it. I have read alot of good reviews on the tenergy 30 dollar balance charger, but it seems to be about the same as this one just has an indicator light to tell you when its dones, and instructions in english.

So you think the battery is F'ed for good? Or will a good charger fix it? Just crazy that it worked that one time.

Hard to say for certain about the battery. Your going to have to try it on a different charger.

The good news is, it hasnt caught on fire. lol

http://www.airsoftgi.com/product_info.php?cPath=27_74&products_id=6333

I have this charger for mine. Works great as a balancer and when your interested in the balance you have left. All my lipos (except one) are over 2800mah and this works just fine with them.

AK-Andrew wrote:Hard to say for certain about the battery. Your going to have to try it on a different charger.

The good news is, it hasnt caught on fire. lol

Amen to that, theres to many horror stories about lipo's. I wont even leave on the charger if im not in the room, although ive heard the same really goes for all batteries you just dont hear as much about the others.

I dont know if this is important info for the issue but I forgot to say the battery is a 2300 mah 20c. i'm wondering if i discharged the battery and recharged it if that would fix it?

if you are careful, you can check the voltage of your battery to see if it was overcharged. it should not go over 4.2v. put the black probe on black and red on each of the other pins to check each cell. do not short it out.

i use a separate voltage monitor to check charge rate on my cheap turnigy charger. it wasn't balancing correctly and the percentage readout was not accurate so i opened it up and adjusted it.

the imax b6 seems to have good reviews for a good price. the lower price ones do not come with power supplies, but i already have several heavy duty power supplies.

ok I will try that tonight and see what i find. I could probablly plug the low volt alarm about halfway into the balance plug and use the volt meter to touch of the low volt probes since the pins in the balance connecter are pretty much covered up.

If its overcharged would that make it not work?

overcharge will reduce the lifespan of the battery. overheating will also reduce the lifespan. the LiPo's i have are rated for up to 5C fast charge but i still charge it at 1 amp or 2 amps charging 2 lipo's at once. i don't wait for the auto cutoff, i just turn it off at 4.10v (i don't fully trust cheap chargers).

Well after last night i tested the p90 again and nothing with the 7.4v so i put my 11.1 on it to try and adjust the motor and just in a matter of maybe 10 bursts the battery was warm, and the mosfet was very warm. Im thinking it may be shimmed wrong causing the motor to work extremely hard to turn the gears, which may also explain why after just testing the kwa and trying to adjust the p90 motor it was tripping the low volt alarm ( motors working extra hard and drawing a ton of juice) i checked the gears motion as best i could but the way the GB is designed I'm thinking i checked the gears and they seemed free spinning but when i tighten the screws after sliding the motor bracket in the gears are packed in and cant spin freely. Im going to replace the bushings anyway so i will break it back down and re-shim it as soon as i get those,
.........BUT I say all that to say I am wondering now if the 7.4 did'nt have enough juice to turn the p90 since there was so much drag on the gears (if thats the case, which im pretty sure it is)

As far as the charger question i stubmbled across a how to on youtube for this one and it looks like a great deal for what it does and the price.

http://www.xheli.com/thac6bachwac.html

heres the video i watched that shows all its functions

https://www.youtube.com/watch?v=Jl-TyLfQBtc

what do you guys think?

if you don't want to disassemble the motor housing, you should be able to check the gear shimming by putting it together minus the bevel gear. but i recommend testing the shimming with the motor removed and gearbox screwed in place. start shimming with the bevel to pinion adjusted correctly. motor height changes will affect the bevel to spur gear clearance.

yeah thats what im going to do. Im going to remove the shims i added and put the 2 screws in for the motor housing and see what it feels like, but the bushings wont be here until tomorrow so i gotta wait, which i hate doing.

fyi rirefox lipos are the worst lipos that you can possibly buy. There 11.1 lipos are equal to about a 9.6v bc there c rating is so low

These 11.1 20c's have a pretty high ROF, high enough for me anyway, as for durability time will tell, but its hard to beat 14.99 a piece. Havent chronoed them to what the actual rps is though.


I decided to go lipo instead of buying more ni-mh and had to buy all my batteries at once and a charger so i had to get something that would let me play while i acquired more.

That 20c rating is a little generous of a rating. But I'm sure it will work fine for your needs.

Right now as long as its safe I'm fine with it. Gear isn't cheap and full-time students/stay at home mommies isn't paying much.

Silent_Option wrote:Right now as long as its safe I'm fine with it. Gear isn't cheap and full-time students/stay at home mommies isn't paying much.

LOL, Tell me about it!!! Mine is my retirement fund but she better get done with school quickly because I got hobbies to pay for!

So i checked the voltage on the 7.4 and got 4.5v from black to red wire, and 8.2 from black to blue. Does that mean anything?

4.5v is too high... shouldn't go over 4.2v per cell.

Silent_Option wrote:So i checked the voltage on the 7.4 and got 4.5v from black to red wire, and 8.2 from black to blue. Does that mean anything?

Yeah thats way to high, its not balancing properly

Would this be a battery issue or a charger issue?

Silent_Option wrote:Would this be a battery issue or a charger issue?

If thats the only battery doing it then more then likely just the battery.