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sigelitest
12-01-2011, 11:02 AM
I am running a 4082 2200kv motor and a 442 prop
On my DF 29 the battery is a 4000ma 4s pack

On a 6 to 7 min run the battery was hot/warm. I didn’t have my heat gun with me but It was slightly bulged. The motor and ESC were cool. The hull has turn fins, tabs and a stinger for a setup.

I am guessing the bat is shot

Doby
12-01-2011, 12:05 PM
Whats the C rating of the pack....is it new or old.........6-7 minutes is a long run time for a 4000mah pack...do you have a meter that shows pack/cell capavity?

sigelitest
12-01-2011, 12:30 PM
it is a 35c it charges at around 3700 the pack is about 6 months old
but i usually stop running it before i kill the battery all the way.
I wasnt on the throttle the whole time.

The pack swelled a little, but went back to shape after it cooled.
I have not noticed that before, but all my other packs are hard packs and I wouldn’t be able to tell anyway.
I just don’t like taking a chance with lipos

eboat
12-01-2011, 01:25 PM
I bet it takes more than 3700 to charge it this time
(you should quite running when it would take 3200 to recharge)

martin
12-01-2011, 03:12 PM
You should not take more than 80% out of the pack or you will cause damage if you havnt already to the battery.

sigelitest
12-01-2011, 03:25 PM
the ESC cut out is set to 13.6 or 3.4 volt per cell

eboat
12-01-2011, 03:37 PM
Your lipo got hot because you have over drained it if motor and esc were cool

kendt
12-01-2011, 03:43 PM
Ya 7mins is way too long to push a pack. My 4400 mah packs never see longer than a 3-3/12 min run.

sigelitest
12-01-2011, 03:55 PM
cell voltage range is around 3.34 and 3.35 is that ok
the only thing i can think is the ESC didn't shut down when it should have

kendt
12-01-2011, 03:59 PM
Ya thats pushing it for lvc. Best not to rely on the esc's lvc. They are notoriously unreliable. I have had issues with them a few times and now I just turn them off and use a timer.

iamandrew
12-01-2011, 06:34 PM
7Min is fine

To be honest, it could be something compleatly un related do the battery, motor and ESC.
I found that my batteries are cooler on my genesis now that i changed to the 150 to 3/16 single peice drive shaft

eboat
12-02-2011, 12:41 PM
Have you tried to re charge the lipo yet ?
If it has shrunk back down I would try to recharge it
Just keep an eye on it when you do
Would be interesting to know how much it takes to get back to full charge

sailr
12-03-2011, 02:05 PM
A typical 1 mile heat race takes 2-3 minutes tops. Anything longer than 5 minutes is really pushing the pack! I suspect the pack is just fine, you are just abusing it.