Battery Death

What’s going on yall, I was hoping for some help with an issue. On my chopper (newer build) it runs great and fine but randomly my battery keeps dying, and it doesn’t slowly die out it’ll be completely fine and then just cut off and totally dead. I’m about to be on my 3rd battery so I know it’s not that, but I’m unsure if it’s a voltage regulator issue or what exactly to just die immediately randomly. The batteries so far have lasted about 1-2 weeks

05’ HD Sportster