Dead battery causes?

Hello gentlemen. I have a 2015 RZR 1000 that I bought last May. I went to go for a ride today in the snow and the battery was dead. It’s been about 3 weeks since I’ve been in it before today but it’s been in the shop. I’m trying to figure out what may have caused it. I’ve added a Wetsounds Stealth 10 soundbar wired to the battery. I’ve also added two light bars. One on the bumper and one on the roof. Both are wired to the terminals under the hood. I would appreciate any input. Thanks in advance.