Not sure what you mean about your Tx battery never goes past 85%??..if it was only at 80% than its discharged %20? that would put my tx down to 8.9 volts and it would fail at 8.5 volts....course it could have been a 3 second glitch that you couldnt recover from no matter what...had that happen, check to see the xtal is in snug too.....Rog