battery cell bad

[Roger1]

my p3 battery is showing one cell is lower, giving me an error about battery bad. It wont let me charge it fully either, 3rd bar starts to blink.

Anyway to fix this? considering the 4th cell is still holding charge fine? example: 4.07v, 4.10v, 4.10v, 3.73v.

 

[flpholt]

run it down to 10 percent then try again

 

[mnewxcv]

I would run it down until the aircraft turns off (at 0%) then recharge.

 

[flpholt]

bad for battery to run it down to 0

 

[mnewxcv]

bad for battery to run it down to 0

0% for the battery in DJI app is not the same as 0% for the cells. 0% in app is still 12+ volts.

 

[DroneDestination]

Run the battery down to about 2-3% (not 0) and see what it says. Just run the motors (no props) on a table or something inside until it reaches 2%.

 

[Roger1]

Ran it down to 0. until the lights will not turn on. lets see what happens

 

[DroneDestination]

!!!!!!!!!!!!!!!!!!!!!
Doesn't seem like a good idea to me; running LiPos to 0% is NEVER good.

 

[flpholt]

!!!!!!!!!!!!!!!!!!!!!
Doesn't seem like a good idea to me; running LiPos to 0% is NEVER good.

very good point not good at all

 

[With The Birds]

Running the battery until the quad hits LVC and shuts down is not the same as draining the battery to below critical cell voltage.

Likely a fruitless exercise in this instance though. 360mv is a significant variation in cell voltage. Without access to the individual balance taps there isn't much you can do to recover from this position.

What is the history of this pack (manufacture date, purchase date, number of cycles)? Has it been subject to elavated temp in storage? Kept at full charge for extended periods?

 

[Roger1]

The battery re-charged back no problem but still shows the low voltage on one cell.

The battery has 9 cycles on it. it has been not in use for atleast 6-8 month

 

[With The Birds]

Did auto discharge work? What voltage was it stored at- fully charged?

What state of charge was it out of storage?

In any case your in the market for a new pack, unfortunately.

Worst case scenario for a lipo pack is storage at 100% charge. You loose up to 40% of the available capacity in 12 months. In your case I suspect it went into storage at low voltage and the cell went under critical due to natural self induced discharge. They rarely recover once this happens.

 

[Roger1]

i am guessing that is exactly what happened. too bad there is no way to fix this.

 

[BW4706]

I had sane problem after my first charge. Go App showed cell 3 was bad. Did a discharge and recharged with no luck. Called DJI in California and they said send it to them for replacement. They emailed me the shipping label while on the phone with them. Waiting for new battery to arrive.