Battery ground disconnect and overcharge

[Steve Darwin]

I know almost nothing about batteries and alternators, but here goes… Arabella has two lead-acid batteries. Battery #2 became dislodged and the heavy-duty ground wire that goes from its negative terminal to that of battery #1 came away, but the ground wire from the terminal to the battery switch stayed attached. We’d been motoring with battery #1 engaged and didn’t notice the problem till we got back to the mooring (no battery indicator light when the switch selects #2, no needle movement on the battery tester for #2, though all was normal for battery #1). After re-attaching the ground to #2, everything seemed ok except that now the battery tester shows that BOTH batteries are over-charged. Did I blow the alternator/voltage regulator – or is this a temporary problem? If the voltage regulator got fried, how can I determine that? Thanks for any advice. - Steve Darwin

[Steve Darwin]

Sorry about the multiple postings - and I had the battery numbers screwed up (#2 battery is the aftermost one in the cockpit locker, the battery whose ground was accidentally disconnected. Looks like I will be replacing the alternator. The Yanmar Service Manual for the 1GM, 2GM, 3GM and 3HM is invaluable. - Steve Darwin

[mgphl52]

Steve, As the original poster of the "multiples" you can go back and delete the earlier duplicates as long as no one else has posted a reply to them!

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Just click on the "X"!