LiPo Battery Question

[Kos-Mos]

If you are using 3 cells (11.1v), Great Plane is making a nice convenient charger.

Part number is GPMM3315
It only do Li-Po, 11.1v and balanced lead only.

[rexdlu]

Originally Posted by txaggie08

I thought it would be pretty obvious since these batteries are common in RC aircraft.


Yes it was an RC plane. a 1.20 sized extra to be exact....


I've seen them burn twice. Once was in a low pass on a .60 sized trainer coming in to land. No low voltage cutoff on the ESC and the battery popped.

The second time was inverted, midair. We THINK one of the cells died and dropped the other three in the pack(flying a split pack setup) below there critical level. Plane caught fire and came down quickly.

I believe it, I run a brushless truggy with a 6 cellLiPo and after dickin around with my hobby shop in the SNOW (yes i kno not smart, but fun) I didn't investigat why it happended, but 2 cells puffed up tripple their original size.

Thanks, Rex

[ginnz]

Originally Posted by txaggie08

Nope, deans are extremely easy to install.

If you need a smaller connector the make gold plated bullet connectors that are even lower resistance than deans.

Be very careful discharging that battery as well. DO NOT drop the cells below 3v per cell. Contrary to the falsehoods being spread on several forums, it is possible for them to catch fire that way. I've seen it happen, in midair, and destroy a plane.

overdischarging a lipo will cause it to "puff"..... and 3v per cell is too low! use the 80% rule, never discharge your pack more than 80%, and it will last long. i never let my lipo's fall below 3.6v per cell. and i balance them each time i charge them.

i have some 3s packs that have over 150 cycles on them, and there still going, although theyve lost some of their "pop"...... i have five 8S 3700 mAh 30C lipo's i use in my T-Rex 600 heli..... two of them have 200 cycles on them, and they charge, and all 8 cells balance fine, although the two oldest packs wont charge higher than 4.16v, but all 8 cells balance at 4.16..... and they've certainly lost their pop, when i hammer down on the collective, the motor noticeably bogs...... my new OutRage 3700 mAh 30C 8s packs make that bird scream...... almost 4 hp on the shaft ;-) (anyways thats another hobby/forum all-together)!

[m102404]

If you're nervous about the whole LiPo thing...go to a good hobby shop that does a lot of cars/helicopters/planes.

Buy stuff from them (might not be the cheapest...but what you'll pickup in hands-on personal info is worth it!). Ask them to show you the different chargers. If you have a charger already and are confused about connectors....bring it with you (your charger...NOT YOUR AEG!!!! although the guys at Hobby Hobby would have loved to see some when I was chatting it up with them...heheheh) and get the guy to show you what's what.

They'll have the connectors there...they'll have wire there. A really good shop might even swap the connectors for you right there and show you how to do it (they might charge for that...but otherwise you're left with trying to figure out how to do it right solely from posts on some internet forum).

Read up before hand about LiPo packs, charging and C ratings...so you at least have a clue what the guys will be rambling on about.

Otherwise....read up as much as you can or try to get a local guy at one of the games to show you what to do.

Best of luck,

Tys