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New lipo the did something scary.

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Old 07-28-2016, 06:10 PM
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tewitt1949
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Default New lipo the did something scary.

[HR][/HR] I just bought a new lipo (http://www.hobbyking.com/hobbyking/s...Lipo_Pack.html).

I charged it completely and then hooked it up to a 1 amp drain just to see how long it would last. One amp is more of a drain then my transmitter, which is 180ma. It started out about 12.4 volts. After 2 hours it was only down to about 10.3 volts. I checked it 1/2 hour later and it went way below the safe discharge voltage just that quick. I tried to charge it and I had to jump start it before my charger would charge. I charged it and all cells took a good charge and appears ok now.

The scary part is what if I'm flying and the voltage gets down to 10.5 volts it might go dead with in the nest 1/2 volt drop. I guess if it gets down to 10.8 volts, put it on the charger.

I'm really surprised it went from 10.3 volts to practically nothing so quickly. Is that normal for lipos to drop off that quick?
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Old 07-29-2016, 03:45 AM
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Quorneng
 
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tewitt1949
1. How much charge did you put in to start with?
2 LiPo capacity can improve after a few cycles.
And don't automatically assume a battery actually has the capacity a manufactures might claim!

On something as important as your Tx never let the voltage drop below the nominal 11.1V for a 3s LiPo. At 180mA discharge it will still be able to run your Tx for at least 8 hours.
Dropping below the minimum voltage (about 10V for a 3s) does irreversible damage to the cell chemistry. The fact that your charger would not initially recharge it means you likely reduced its maximum capacity further.
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