Posted 9/9/2022 19:57 (#9837190 - in reply to #9836426) Subject: RE: DJI Phantom 4 controller not charging
When lithium cells fall below a certain charge level, they may no longer take a charge. Best to replace the batteries.
I have managed to bring some of them back with a variable power supply, using higher voltages and limited current.
But I wouldn't recommend this procedure to someone not familiar with the technique. You have to monitor current and temperatures carefully to avoid a thermal runaway and possibly fire.