god knows what happened to my j3 piper, when i attached my 1250 mah 11.1v wolfpack, it became hot and swoll  and died in a minute, i thought sth happened to my battery and connected other battery 6 hrs later, this time zippy 1000mah 11.1v, same thing happened... what can i do ?? throw the model??? it was brand new,.. just 1 flight done...landing was not that bad.. tail crashed but got it fixed...is sth wrong with esc???

Did you check the + and - symbols on the ESC and ensure the right leads matched from the battery?

it is an rtf...we used a deans connector that worked perfectly fine the previous flight

red was with red b with b

bro .that may be u use more than minimum neede volt.9v.or there may be a bad connection problem.do u see any sparking?

check the motor to esc wire is properly insulated

I thought the same... The connectors it originally had was of 7.4 v cell but the specification given in rcbazaar for this product was 11.1v so I desoldered it and connected deans... But it has 1700kv motor and 18amp esc... What's your opinion?? I previously had a flight and that worked perfectly fine.. How can it suddenly not accept 11.1v??

it cant happen.even though there is some case.if the connectors are, ok the 3s 18a es c and 1700kv motor burned some particle of ur esc.upgrade it with 25 amp or 30a esc

Roby were you bought this??

Both times esc beeped... Then stopped.. Usually they beep for long .. C'mon whr r the experts?? Escs not broken

Mr Moorthy I dint get yah :p

And batteries and connectors are fine... Works well with another electronics

Were you bought j3 piper cub

roby - its very difficult to understand what you are saying thats the reason
none of the experienced people have commented.


please from the beginning ... explain properly

also try and post a picture

did the two batteries swell and die immediately upon connection
or did it swell during the flight ?

Quote from: roby on February 22, 2014, 06:12:12 PM
And batteries and connectors are fine... Works well with another electronics

first you have mentioned battery swell and died and now you type battery is fine with other electronic could you be clear

Most common cause is you exceeded the battery capacity by drawing too many amps too fast.

1700 kv motor.  What prop size did you use?

Kindly tell exactly what prop size, motor, esc and battery rating used by you. Also, although I know this is very small thing, still since two batteries died so am asking this... are you sure you soldered the T connectors(Dean connectors) properly. + and - are usually printed on the sides of connecting terminals. A pic of the whole setup would be helpful. Its really shocking and sad two batteries died simultaneously...

look, what i meant was i was doing a workshop for my college fest, i connected wolfpack, that died...i though sths wrong with the battery, i used zippy.. that became hot..got swollen... but is still working with other electronics as of now..but i dont think that'll last long..that already looks like an airbag

did you change connector in zippy lipo? what mah zippy you used?

prop size 9 inch..motor 1700kv esc 18...have mentioned these :p

and where am i not clear? it might sound crazy.. but then u are most welcome to test it with your lipos... i'd be glad to ship it

Mr. morthy i bought it from rcbazaar..

and i dont wanna risk any more of my lipos :p i dont have many :p

i dint... but i did that with wolfpack... how does it matter anyways? it was a 1000 mah 11.1v
what i was thinking was is it because of the voltage? but in the rcb specifications 11.1v was required

check the soldering , low quality plugs usually melts from inside while soldering, jst a random thought.....

checked it...cant see anything wrong there... is there any way to check by suppying some dc power? don't want to end up with burned lipo again

Did you try using the battery with another esc? There can be short inside the esc. You can remove the heat shrink and check if anything is burnt, if you cant claim a replacement or warranty.

Or the motor can be burnt. Try to use it with different motor.

And if the second battery got swollen, so should the first battery I assume, as you have mentioned it died?
If both the batteries got swollen then the culprit is a short circuit somewhere. You have to check each item by plugging them with other esc's or motor to ascertain what the issue is exactly.

You mentioned the battery has swollen up like an airbag. If you aint exaggerating, then get rid of the battery before something goes wrong. Lipos are unstable and dangerous you never know when it lights up particularly if its damaged. Similarly expect the soldering in the dean to be perfect without any shorts.

While mentioning items please mention the make and also size of the motor, discharge rates of battery and esc's. Makes things easier.Right now how do we know whats the current your motor/esc are rated for and voltage your esc/motor is rated for?

There's your answer.  9" prop on 1700 KV on 3s Lipo.  I'm estimating burst of 40+ amps at full throttle and 275 plus watts.  Something had to give.  Either the ESC or battery will burn out.  You got lucky if your ESC survived and only the battery died.

You can put in 100 brand new 3S lipos and run them all with the same result for each.  If you insist on using the 9" then upgrade the ESC and go to at least 3000 mah 30C lipo but ecen if you do, your motor will burn out instead.

With a trainer style Cub with a flying weight of  > 500 grams, you just need about 120 watts.  Those Cubs will fly on 8 and even 7" props depending on motor KV.