The battery was reused and i tried the amplifiers with a modification but came to the conclusion an all in one solution probably would work better. A TPA3110 with bluetooth would just fit. First power on was not what i expected. A chinese lady would welcome and tell the name of the device it has connected to. It was very bad. Sound quality was again a disaster. Also the speakers could not handle the power. Not much time later the thermal protection kicked in. This board was not able to be used at maximum volume for a long time. For fun i hooked it up on a roadtrip on two 12 inch speakers and boy it was loud. I'm impressed with these class-d chips.