Battery / charger question

[Legend]

I had an issue with 2 group 27 batteries wired in paralell last week
My boat has the 2 froup 27 and 1 group 24
- the batteries were connected to shore power with the charger - checked the water and they were dry - 14 month old batteries? Filled them up with distilled water and tried charging them - the batteries were very hot to touch and the charging system green on the single battery but red on two that had gone dry. Ended up replacing the two group 27 batteries and the charging system went to green after 10 minutes .
The question I have is around the battteries running dry - Wonder if the charging system could be bad or maybe a bad battery that would not hold a charge and the system kept running to charge and fried them?
Does anyone know how to check the charging system - It is a Guest - I dont want to damage 2 new batteries if it is bad- Thanks for any tips

 

[Curmudgeon]

I'd get a battery cherger with has multiple leads, one battery can't screw up the other. I know nothing of your set-up, but I'd wager more batteries are killed each year by over-charging than any other reason. The second reason would be loss of water before charging (I check at least monthly), the third would be paralleling with a weak/bad battery. 'BOTH' position should be an emergency procedure ... :wink: