Some good information here thanks all y'all! I think for now I'll shut the system down, I don't need it at this time. This year has been a shakedown journey and now I have one more thing on the list to buy (kaching!), dang!
FWIW I had a battery blow up in my face when I was a kid. I tried to jump start a wet engine at a car wash. Fortunately, I was able to hose myself down and also had fast enough reflexes to jump back and shut my eyes as the top of the battery case flew up into my face. I learned then, when jumping a car battery, to attach the ground wire cable to the car frame, far from the battery.