I know of a neighbor that bought a brand new sealed battery and a Plane Power Alternator. The alternator model was the one selected by Plane Power for the set up on the aircraft. Two hours of flying destroyed the battery by overcharging. Plane Power determined the wrong alternator had been selected and agreed to replace it (and the regulator) with the correct one. They would not replace the battery. I know this is a tough call. Just curious if most would expect a battery replacement in this case. Apparently the correct alternator was more expensive and they felt it offset the battery loss. The vendor exits with damage under control. The customer leaves with a bad taste in his mouth and a horror story to tell.