1998 GMC Jimmy voltage too high

A few days ago my wife's truck died while at a friend’s house. No power, no turnover. After her friends tried jumping it for about 20 mins they finally noticed the battery was bone dry (I didn't even realize they still sold batteries that needed water). They filled it up with distilled water and it started fine. Next day she goes to start the truck and gas gauge dies and battery light comes on. After a bit I notice a few blown fuses. Replaced them, they worked for a while and blew again. Hooked up a volt meter to the truck and noticed it's putting out over 17 volts. Figured the alternator was bad, took it into the store and tested. It passed. Figured better safe than sorry, installed a new one anyway. Now it's still reading over 17 volts when on and blowing fuses. I tried draining the battery down (it was at over 14) and that seemed to work for awhile, but the problem keeps coming back.

Could the battery be the culprit?