12V battery issues

[Resoman]

I bought a new battery for my 2013 Forest River PUP last fall and stored it in the garage, giving it a full charge every month and disconnecting the charger (NOCO G1100) between charge cycles.
When I went to use the trailer this spring, I found that the A/C unit and the lift mechanism had died over the winter, had them both replaced, to the tune of $2K.
I got the rig home from the shop this week, took the battery into the garage and hooked up the charger. I was surprised to see the charger initially indicate only a 25% charge, and left it connected overnight.
Today, it's still showing only 25% charge, and I'm concerned that I've had another battery die on me. Water levels look fine.
I assumed that the one hour drive home from the repair shop would top off the battery charge, is that reasonable? It sat at the repair shop for two months.
Tomorrow, I'm leaving town for a couple of weeks, but will leave the charger connected for another 24 hours and see if things improve.
I'm in sunny Texas, FWIW.
Any thoughts from battery experts will be appreciated!

[wa8yxm]

Several possible issues.
1: You say the charger shows only 25%.. How big is the charger, How big is the battery bank, and is the charger properly calibrated

What does the RV panel display,. a known accurate digital volt meter (I have a calibration procedure on my other computer but it's in the shop just now)

THe shop clearly did not maintain the battery

Is the battery a flooded wet cell? Did you check the fluid level (Or is it maintenance free)

All these affect reply,

[MEXICOWANDERER]

Take rig in for service.

Show service writer eyeball to meter reading battery is full. Lights work.

Pick up rig.

Battery dead

Search out same service writer right then and there.

[Resoman]

All,
I'm back from my travels, and was able to convince the RV repair shop to replace the battery that went dead while they had the trailer.
Thanks for all the replies!
Gary

[MrWizard]

If that battery is not in a charged condition now
Leaving it for another two weeks is not going to help it

You might as well plan on buying a new battery, and a larger charger

For the record
A one amp charger is used to Maintain a battery that is already fully charged
And you leave it on the all winter, you done disconnect it

[Resoman]

I contacted NOCO and they confirmed that my 1.1A charger won't be effective on a deeply discharged battery. I'm leaving town for two weeks; I'll get it charged and analyzed when I get home.
Thanks to all who have commented!

[pianotuna]

Driving for an hour may do little to charge a "house" battery.

[MEXICOWANDERER]

Like trying to put out a brush fire by ------ on it.

[drsteve]

The NOCO 1100 is only a 1.1A charger. According to NOCO:

Charge fully drained lead-acid and lithium-ion batteries up to 40Ah, including ATVs, lawn mowers and motorcycles. Safely maintain all types of automotive, marine, RV, powersport, lawn & garden and deep-cycle batteries.

It's too small, not going to get the job done.

[CA_Traveler]

Resoman wrote:
it's still showing only 25% charge, and I'm concerned that I've had another battery die on me.

Another battery suggests maintenance issues, charger issues or the rig is discharging the battery when it should not.

It sat at the repair shop for two months.

Bad stuff can happen at a dealer in 2 months. Accidents, "Borrowing" a part for another repair, discharged batteries, etc.

You dealer may be one of the better ones but I would never leave the rig that long for repairs. For you I'm thinking 1 day for assessment and bring it back for 1 day of repairs.

[MrWizard]

Several members have a noco charger
IIRC it won't charge a really low battery, You need to use a different charger, to bring it up to where the noco will do it's maintainance thing

[CA_Traveler]

Often the long wires from the alternator to the battery are inadequate to charge a battery due to the voltage drop.

It's very common for batteries to become discharged at a dealer and that can be a battery killer.

Have the battery load tested at any auto store for free.

Also a 25 percent charge suggests idiot lights, is that correct? They are only good for the salesman to sell you the rig. Start researching your charger, wiring and battery. Low quality chargers often don't adequately/correctly charge batteries.

Above all else buy a voltmeter with which you'll know a lot more about your battery charge and condition. $20 tops and the free HF ones are acceptable. A good hydrometer is the best device for checking a battery and more involved than a voltmeter.

[red31]

take it to an auto zone, they will charge and test it.

How long would a 1A charger take to fully charge it?

[Flyfasteddie]

I assume your charger bases its state of charge percentage on voltage. If that is the case your resting voltage is around 11.7v, and that's after your tow vehicle did some charging on the way home. No bueno.

If the battery was charged when you took it in, and being only a year or so old I would guess that someone at the shop left something on in the trailer and killed the battery.

[Flattop1]

I would verify that the constant 12v power in your tow vehicles 7way is good (1 o'clock position) may have a blown fuse