battery questions and issues

[CODan]

new RV owner here - 2000 Tioga 24', had it thoroughly checked on and repaired when we got it, then it sat for 2 years unusued. Now I'm trying to get systems going.

Batteries were brand new 2 years ago.

When I parked it I pulled the 2 6V batteries (which were wired in series) and put one of the batteries on a trickle charger I use for my car and motorcycles. Unfortunately I charged ONE of the 6V batteries at 12 volts for about 12 hours before I discovered my mistake, then switched it to 12V.

Did I ruin this battery?

I correctly charged the other battery at 6V.

The batteries check out at 6V each when tested individually, or 12+ volts when wired in series.I took a photo for reference before I disconnected them so I know I got them right.

I've put the batteries back in, wired in series , but have problems when checking things out on 12V.

Everything works perfectly on 120 volts - heater, water pump, lights. But only the lights (LEDs) work when on 12 volts.

The water pump runs on battery (very quietly) but doesn't pump any water. I can't hear any water being moved at all. If I plug into 120 it works perfectly.


And it seems like the voltage goes down VERY quickly.

Any thoughts?

Thank you. I'm not generally dumb (just RVs) so maybe I'll be able to help one day.

[2oldman]

CODan wrote:
Well, someone that knew what they were doing came out and looked at my batteries. No liquid at all.

Several of us said that. First thing.

[CODan]

Well, someone that knew what they were doing came out and looked at my batteries. No liquid at all. I'd never opened the battery (never occurred to me that I could) so I killed them somehow. I think that maybe I left them in the RV over a CO winter, uncharged, and I had forgotten that. It's been a tough couple of years.

2 new batteries and everything is good.

My wife says "It's a learning process" and I'll take that point of view.

Sorry for the stupidity, I'm an idiot on electricity.

Thanks to all.

[wopachop]

CODan wrote:
No, were not uncharged. I charged them over the 2 years they sat in my garage, just used the wrong voltage the first day and now I have trouble with my 12V systems.

Thinking more about this, i wonder if its just a connection issue. Make all the metal parts shiny and put it back together.

Doesnt sound like his batteries are dead. Could just be a dirty ground.
You could probe the battery terminal and have someone turn on the water pump. Take note of the voltage drop.

Also try probing the lead battery terminal, then probe the actual wire. Ive seen a huge difference when you probe the nut that tightens the wires down, versus probing the actual lead terminal.

[CA_Traveler]

A $20 digital meter is adequate

[KD4UPL]

If your voltmeter won't read "as exact as 6.4" then it's worthless. Get a good voltmeter or your just guessing.
A 12v trickle charger likely won't damage a 6v battery in a few hours. Not checking the water in flooded batteries for 2 years likely will damage them.

[pianotuna]

Bob few folks have a charger that could equalize a 6 volt jar--so I suggest put them in series--and equalize charge them. I'm sure that's what BFL13 was talking about.

Try and keep your cool with this heat wave!!!

[BobsYourUncle]

BFL13:
He has 2 - 6V batteries... 🙂

[Grit_dog]

Can’t follow your story on the batteries and won’t try.
And no reason your 12V stuff is not working if both batteries are over 6v, if even for a little while if they’re weak.
Get a hydrometer if you actually want to check the batteries.
Get a better multi meter if you intend on doing any electrical work.

[BFL13]

Load tests are done on full batteries, but OP does not know if they are even close to full. An hydrometer would answer that.

The charging that was done on and off the past two years was a good thing, but as well, you should have charged them right up at 14.6ish volts every couple of months so they won't stratify.

Hard to say if they can be "recovered" from that, but maybe. You need to recharge them to full as they can get at 14.6 now and then do an "equalize" for a few hours at 15.5 or 16 volts, and see if the SG is up close to where it belongs with your hydrometer.

[pianotuna]

CoDan,

I'd suggest doing an equalization charge.

[wopachop]

CODan wrote:

CA Traveler wrote:
Absolutely hands down a load test by a good battery shop will answer your battery questions far better than any other test. An auto store is not a good battery shop

I'm 4 hours from the nearest "battery shop" I'm sure.

Dont worry about it. That was bad advice you should not follow. Reason is because the load tests will often call an OK battery a bad battery. Im assuming youre trying to save money or you would just buy new batteries.

[CODan]

CA Traveler wrote:
Absolutely hands down a load test by a good battery shop will answer your battery questions far better than any other test. An auto store is not a good battery shop

I'm 4 hours from the nearest "battery shop" I'm sure.

[CA_Traveler]

Absolutely hands down a load test by a good battery shop will answer your battery questions far better than any other test. An auto store is not a good battery shop

[jdc1]

Just continue to charge them overnight, then go from there.
Disconnect the charger.
Let them sit for an hour or so before checking the voltage again.
Then get back to us.