Green Models 1:7 Tiger Moth Battery Puff

[mkxiv]

Well been flying this thing for a year now. Have about 20 flights on her now with the below setup.

E-flite 60amp esc
E-flite 3 Cell 20c 3200mah
Motor - Emp EMP-C3542/05 1250KV
Apc Prop - 11 x 5.5
2 standard servos plus 2 misco servos

Yesterday: powered up and up she went. Got up about 50 feet and the power stopped. She started gushing smoke. I was able to set her down but the smoke was billowing out! I ran over and ripped the battery out. Airframe is Ok, ESC is ok but the receiver lead is melted badly in one spot. Battery is cooked.

My questions are what makes a battery do this?

Also what is the best way to fix the esc receiver lead?

[eye4wings]

Bit of a fright eh?
Do you know why the receiver lead was melted? Was it in contact with the battery pack?

As to the cause of the failure was the pack balance charged or not?
Most problems seem to result from cells getting out of balance within a pack, causing the lowest to take serious punishment.
It is possible that the pack may not be completely useless. On occasions I have found only one cell to have died in which case - and with care - the dead one has been removed and the remainder balanced and recharged to be put back in service.
So don't just bin the pack without checking the voltage of each cell.

You mention 'puff' - do you mean that you were aware of them having puffed up prior to flight or that they were after?

Possibly the receiver lead was overheated breaking down the insulation and causing a short of red and black - but then again you landed safely (apart from the smoke and wear and tear to pilot!)... Were you using a separate UBEC?

Sorry - lots of questions and no definite answer as yet.

[Jim_Marconnet]

Sounds to me like your best bet is to look for a knowledgeable local who can look at your equipment and make suggestions.

Like eye4wings, this seems to be much of a mystery to me without additional information.

I used to try to reuse packs with a puffed or shorted cell. But I decided after a while that the risk was too high for me, compared to the cost I now pay for new packs ordered directly from China. Now I only use packs that I have opened up/modified to run my battery-operated string trimmer!

Jim