Electrical Gremlins on my '14 LSV - Could it be Battery Issues?

[North Woods Mobius]

I jumped in our LSV yesterday morning to fire it up and head out, and I had a dead Battery #1. No problem, I just switched it over to Battery 1+2 and it fired right up. After we drove a bit, I switched it over to #1 figuring I'd be able to charge #1 as we boated around a bit and everything should be good to go. The amp gauge looked good and I assumed it was all sorted out. When we started to get ready to surf, I turned on the ballast pumps and got nothing .... I checked the fuses, and they were all good. So I shut down, turned the battery switch to OFF, then over to #2, restarted the engine and started the pumps and all was fine! Additionally, my wake plate was frozen until I switched over to #2.

So my question for you guys is if you think I just need to replace Battery #1. It didn't seem to hold a charge when running, and I had some systems fail when only on #1 (but fine on #2). Also, would you suggest that I replace both batteries at the same time, or wait until I have a problem with it? My '14 LSV has ~175 hours on it and I currently don't have it on a trickle charger during the season while it's on our covered boat hoist.

Thanks for any suggestions on this!

[zabooda]

Dead battery which can be confirmed at an automotive store. No need to replace the other battery as you have the isolator. Newer batteries can still fail.