I have had this problem, eventually, with all the re-chargeable battery packs in my controllers. The problem seems to occur when you continually run your battery completely flat, too many times. The usual problem symptoms are, charging cable LED briefly turning RED (charging) but then turning GREEN (charged) 5-10 seconds later, indicating a full battery. However battery is still flat. This is a false reading given by the charging cable, which interprets that the battery is full, when it is actually dead flat. There is a fix, which I discovered awhile ago. This method can take more than a day sometimes, but what I did was continually repeat over and over and over again until it charges properly and the LED stays RED, indicating a proper charge. It may take 30 tries. It may take 300 tries. It will almost always eventually fix the battery though. 1. Plug charging cable in. 2. Charger LED should be RED indicating it's "charging". 3. Wait for charger LED to change from RED to GREEN. 4. Quickly unplug charger. 5. Rinse and repeat. This will trickle feed the battery, so the charging cable can eventually detect the battery is flat, and will charge the battery as it normally should then. This method may take awhile, just be patient and stick to the process.