So, I tried to exercise my generator a few months ago. Wouldn't crank. Finally got around to diving into more detail this past weekend. When I tried to crank, voltage across the terminals went to ~4V. Pulled the caps off the batteries (there are two of them - 2 x 12VDC wired parallel, Deka deep cycle DC24). Plates were dry.

I put in about 2 gallons of distilled water to bring them back up to full. After charging all night, still no crank.

Dang, stupid hurts! I know, I know, I need to check them once in a while.....

On a related topic - any recommendations on decent deep-cycle batteries that are Group 24 sized?

Two gallons? That seems like a lot. Might want to check that those batts aren't leaking.

My camper has hardwired CO and propane detectors, and will drain the battery if it is left connected parked without power. My first battery froze when it discharged.

Edit: I replaced mine with a used deep cycle Deka, it works great. Have an Interstate deep cycle on a dump trailer, and it is also problem free since new a few years ago.

Pretty sure they aren't leaking, I didn't see any evidence of it. I'll look again today. However, even if they are leaking, it means they are toast.

I'm a full timer, so it wasn't left parked without power. Which also means I should have known better too. In my defense (shallow though it may be), they are kind of hard to get to. I have to crouch under the nose of the fifth wheel and hold up the battery box cover. The cover has external terminals, so that means the batteries are wired to the inside of the box, making it more difficult to lift up, support and maneuver around.

I would recommend a quick disconnect plug to so it's easy to connect a charger/maintainer and a schedule to check the electrolyte. That will keep the batteries at a higher charge.

Anytime it's charging, some of the water is evaporating if it's vented. If you have two particular cells that were much lower than the rest, that may indicate that those two were starting to fail and lower voltage than the the others.

Might be worth checking that the on board charger is not overcharging the batteries.

When you have a lead acid battery that is discharged , the clock is ticking . Dry cells , you're adding to the death sentence .
Verify the functionality of the charger but it sounds like your batteries are toast .

I'm pretty sure they died from neglect. It's on me. More diagnosis may be required, but I know I failed.

Now I'm running the rabbit hole of lead acid flooded vs. AGM vs. LiFePO4 (Battle Born or similar). Need to find my inverter manual....

Costco sells deep cycle batteries for golf carts 6v and 8v if you are near one, if these are over a few years old they are probably done, especially if left dry.

I would look at replacing them with a lithium battery pack that is rechargeable considering the difficulty to get to them and replace the water in the Lead acid batteries..

Imagine the tips on doing that are on some of the RV forums. When the Lead acid batteries on the golf cart take a dive I'm converting it to lithium which should last longer holding a charge and being 300 pounds lighter, improve speed and acceleration...

Get a Batteryminder and use it.

Battery Minder isn't the issue. It's always plugged in to shore power.

Unless by "Battery Minder", you're talking about something that slaps me on the back of the head and tells me to go check them....

quote:

Originally posted by IntrepidTraveler:
Battery Minder isn't the issue. It's always plugged in to shore power.

Unless by "Battery Minder", you're talking about something that slaps me on the back of the head and tells me to go check them....

"Desulfation keeps battery free of sulfate or dissolves sulfate completely in older batteries."

I keep the battery minder on ours even when it's on shore power.

quote:

Originally posted by IntrepidTraveler:
Battery Minder isn't the issue. It's always plugged in to shore power.

Unless by "Battery Minder", you're talking about something that slaps me on the back of the head and tells me to go check them....

Well if I weren't located so far away.........

How old are the batteries? How often do you check their water level?

Depending on the answers to those questions, I might look at your onboard charger to make sure it's working properly. Too much voltage to fully charged batteries will boil the water out in short order.

Assuming the charger is fine, you need to get on a schedule to check the water levels or get some AGM batteries.

The Lithium type batteries are dropping in price and can be discharged to the 10% level or so with no damage incurred. They’re much lighter too.

Best wishes to you.
.

quote:

Originally posted by IntrepidTraveler:
Battery Minder isn't the issue. It's always plugged in to shore power.

If you had to pour 2 gallons into two batteries, your "shore power" charger is killing your batteries. It is boiling them and killing them.

You need to look at your charger. It is supposed to charge then float. Yours apparently is not entering float stage and is just dumping amperage into the batteries, boiling off the fluids.

Thats my best guess anyways.

What type of charger is it?

Id be tempted to use a battery tender. I have never had them boil off a battery and they keep them full all the time.

This message has been edited. Last edited by: bubbatime,

or, he's not checking them regularly and it boiled the water out over time since none was being added... Doesn't take a long time...

Link for Reference Lithium

Two gallons in two group 24 batteries? Yeah, way too much, probably bone dry with warped plates.

I get nervous when the Rolls/Surrette 2-KS-33P (1700 amp hour, 2 volt, a little over 200#) batteries take more than a quart.

Yep, step up to the plate and buy one (or if you want to increase your capacity, two) Lithium Phosphate 100 AH batteries.

I made the switch a few years ago and love how much usable energy they have, how fast they recharge and how light they are….

A suggestion for battery replacement.
https://youtu.be/-c6A1THDaeU

Straightshooter - thanks, I appreciate the offer!

Trapper, Bubbatime, HRK - it's negligence on my part, I've had my fifth wheel for a bit over two years. I'm sure that's plenty of time to boil the water off.

Bubbatime - it's charging via the onboard converter, a Progressive Dynamics PD4575. I still want to diagnose, but I'm reasonably sure the converter is working OK. Like I said, negligence on my part.

OKCGene, HRK, Hvactech - I like the idea of Li batteries, but I'm probably going to end up with AGMs I think. For my converter to work with Li batteries, I need to swap out the charging board at about $160.