don't know if you have fixed the problem but my controller did exactly the same go on youtube and look for the fault there you will get lots of videos on how to fix it you take the back off in 2 parts disconnect the internal battery for a minute or two put back together and it should work fine no cost involved mine works perfectly now
Hi there the problem with no charge or less is the chip next to the lights on right hand side has dry solder ' so u tube how to strip down then get a heat gun or take to computer shop and ask if they can reflow it.....
It's easy do e lots of these do t panic " see attached image for the chip in question
A BIG thank you to Ashy01 for the pic of the offending area. I have had issues with mine too but after your description I went back in and put 350' c on that little sucker for 15 seconds and another 15 on the other side for good measure. I had been reflowing for 3 times previous generally all round the main board with some success but it would eventually revert back after a few week but it meant I was close to it. Funny though as I disassembled the rc their was No voltage from the battery so I bypassed the balance board by soldering to the other side of the board ....fairly quick and simple but also demonstrates there are issues in there as well. All good so far.
There maybe something at play between the balance board and this tiny ic chip.
Anyone with issues (out of warranty) I recommend balance board bypass and the ic chip reflow at above temps/time.