Hi all
I have a rechargeable battery from a motorcycle intercom headset, when measured with the meter directly at the battery tabs reads 2.3v it should be 3.7, however, taking a reading on the output of the charge/protection board it reads nothing so I’m assuming the mosfet on the board is possibly failed and I can’t find one anywhere only number in it is 8205A, loads of sites have the data sheet but can’t find the actual component.

If anyone can find it or let me know if an alternative it would be greatly appreciated

 

Hi all
I have a rechargeable battery from a motorcycle intercom headset, when measured with the meter directly at the battery tabs reads 2.3v it should be 3.7, however, taking a reading on the output of the charge/protection board it reads nothing so I’m assuming the mosfet on the board is possibly failed and I can’t find one anywhere only number in it is 8205A, loads of sites have the data sheet but can’t find the actual component.

If anyone can find it or let me know if an alternative it would be greatly appreciated

The protection board may be shutting down the connection to the LiPo to... protect it. 2.3V is 0.2V below the common low voltage cutout. Try using a bench supply set to 3.5V to directly charge the LiPo to above the threshold and see if things start working.

Don't leave it unattended, and monitor the current—avoid going over 1A. It really isn't much of a risk since you are seeing 2.3V but before you reassemble everything, make sure they cell didn't develop and internal shorts. Put it on the normal charger and check that the battery doesn't heat up (excessively). Then discharge it and try again, a couple of times.

If it passes this test, reassemble it and enjoy your ride.