Is Power Booster working

I’ve been using the first prototype Power Booster for about 2 yrs now and noticed recently that my battery level is lower than it used to be. Is there a way for me to check to see if its still working? I did get the released version shortly after it came out but haven’t hooked it up since my other one was working fine.
Station ID is 15419
Battery level is currently at 2.63v but normally was at 2.77v

If running the Proto Field Test Power Boster on 4 x Lithium Batteries. . .that might be one explanation. . .even IF the batteries are Brand New… I recenlty had to dig my Proto Power Booster out because of 8 x Cloudy Days (all 3 of my ST devices were running low because of No Sun). .and it worked just fine. . .using the supplied AC power adapter. I had to alternate (ST devices had to “take turns” on the Proto) but they all 3 charged up to max voltage . . . 2 of them got up to 2.81v and the “Backyard” device got up to 2.82v. . . .taking slightly less than 2 hrs for each one to “perk” up!

I am using the AC adapter with the Proto Field Test Power Booster. Should I switch it out with the Production version to see if it makes any difference?

It is definitely worth switching it out. The prototype was not designed to last very long in the weather, though mine is still working fine on the AC adapter.