My batteries overcharged themselves

[JuiceClark]

We have a real twilight zone deal here.

I'm on the boat at least 3 times per week (in back yard) and always keep the batts at 32v. The battery charger is always off at the breaker. When they need a little charge, I simply flick the breaker and let it run while I'm doing something on the boat.

I think it was Monday...I last checked the batts and they were 32.1 on P and 32 S.
Tonight, I hopped onboard and saw them reading 33.8 - both banks! I touched two individual batteries and they read 8.5v.

The charger breaker is off and I haven't run the boat all week. I put the battery tester on each bank 3 times. I'm flabberghasted. Either my tester has malfunctioned in the strangest way or somebody took the boat for a run in my absence! The engines are cool. The breaker is off and it doesn't charge over 32.5 anyway.

What in the world is going on?? Freaky man....

[SKYCHENEY]

They only charge to 32.5v?? Mine float at 36.1v and bulk charge at 38.4v.

Are you sure about your charger voltages?

[JuiceClark]

They only charge to 32.5v?? Mine float at 36.1v and bulk charge at 38.4v.

Are you sure about your charger voltages?

Well, I guessed on that...just having noticed the charger doesn't come on if the reading is above 32.5 on starboard. I always go by what my tester reads at conveniently located circuit breakers - and not on the charger way back in the front corner of the ER.

I have those circuit breakers on each bank between the batts and the charger anyway. I keep them tripped when not running the charger .... and they are tripped open.

Both banks (of 8 batts each) gained more than a volt since monday, with the charger breaker off at the box and the circuit breakers tripped.
That hurricane was hard on me....might be losing my mind.

Wish I had a backup battery tester, just because I can't imagine what else.

[madhatter1]

Get a decent meter from Home Depot. Less than $100. I use one with an amp claw. Very handy tool. My stern light had a bad bulb but would not light with a new one. After spinning it with no luck I used my meter to find I was getting 12v to the wire but 12v was not making it through the connections within the light fixture. Took apart and fixed. No meter and you would never figure that out.

[Dan Mapes]

It's been quite a bit warmer lately?

[Pascal]

A quality multimeter is a must have on a boat. Old analog gauges aren’t precise enough that s why I like the Blue Seas digital panel meters. Precise and visible.

It s been a while since I ve had to deal with 32v system but charged voltage is about 33.5/34v isn’t it? Just like a 12 or 24 bank is pretty much discharged at 12 or 24 v

Why all the connecting or disconnecting? I ve always left my chargers on 24/7

[rsmith]

With the charger on should be 36 volts there is a bunch of threads on here.

[Scarlett]

Should float at 33.4 bulk 38.4

[metama]

yep, 36.3V charge, 38.4 bulk.
Get a good charger and leave it on. Letting battery drop to below 32 and then charging them up to 32 and turning off the charger isn't good for them.

I switch over to analytic systems for a quality charger.

[bostonhatteras]

Get a decent meter from Home Depot.

oxymoron? jk