Did I damage my house batteries?

[MetalGator]

I replaced my house batteries back in August of 2020. I got 3 1/2 years out of the first set of house batteries (bought motorhome new). We are going on a trip tomorrow so I checked the water level in my batteries and noticed white crud on the battery strap. One of the batteries was swelling and was wet. These batteries are only about 2 1/2 years old. Called the local RV shop and replaced both of the house batteries. When I checked the new batteries, the water barely covered the plates.

I always fill the batteries much fuller than these new batteries were filled. I am wondering if I have been overfilling my batteries and that is why I am not getting more time out of them (and the swelling). My first set of batteries swelled as well.

I do keep my motorhome pulled in 24/7 so there could be an issue there as well.

Any advice to get more time out of my house batteries?

Burch

[2oldman]

Freezing is also a cause of swelling. Any chance that happened?

[MetalGator]

Thanks for the responses. My motorhome is a 2018 Thor Miramar 35.3. I will have to look at the inverter/Charger and see what the model is. The old batteries were still working fine but once I saw the one battery swollen, I wanted to change both of them.

Would turning off the battery switch while plugged to AC at my storage facility keep the batteries from overcharging? We do have stuff in the fridge so still need to be plugged in.

Burch

[JimK-NY]

What is about AGM battery charging? Mine charge at 14.3 and float at 13.3.

[time2roll]

Fill to 1/4" to 1/8" below the split ring that extends down into the cell. Fill after fully charged as the electrolyte will expand as it charges. Although the plates need to be covered before charging. Just touching the split ring is absolute max and may still have some electrolyte pushed out and cause corrosion. Swelling and wet of one battery sounds like a shorted cell and is fairly common.

Charging voltage can make the issue worse. Plenty of equipment charges at a voltage too low and floats at voltage too high. Post the converter or charging equipment make and model number for best answers. Also make sure the battery is not allowed to discharge below 12.0 volts while in storage. Float at 13.2 will work well for storage. May need to get a voltmeter to verify actual conditions.

I recommend LFP replacements next time.

The 12 Volt Side of Life

[2oldman]

Johnny G1 wrote:
You want to get your charging unit checked first before you even think of going AGM batteries as they usually take a different charge pattern,

Are you thinking of Lithium? AGMs may vary, slightly, but not to have to change out charging systems. They're still an acid battery.

[Johnny_G1]

You want to get your charging unit checked first before you even think of going AGM batteries as they usually take a different charge pattern, I have had batteries last as long as 14 yrs so there is something wrong in your Mh.

[2oldman]

JimK-NY wrote:
you might want to consider AGM batteries next time. They cost more but generally last longer and do not require maintenance.

Yeah, or lithium.

[JimK-NY]

After checking to be sure you are not overcharging, you might want to consider AGM batteries next time. They cost more but generally last longer and do not require maintenance.

[Grit_dog]

Agreed, not overfilled but likely overcharged.
Fwiw I typically fill flooded batteries to almost the top of the slot. Not an issue for boiling over if not egregiously overcharged.
If your converter isn’t smart enough to trickle/float and/or you have a WFCO converter that actually charges like it should it may be the cause of cooking a battery or 2.

Another possibility but not likely is the alternator on the rig “could be” overcharging them.
Hard to tell though based on your observation, presumably after a long storage.

[johnhicks]

Battery water level should be at the bottom of the tube/slot or slightly lower but still covering the plates when looking down the filler hole. It should never be actually full. A common plastic battery'watering jug will take care of the level.

Sounds like they're being overcharged. Right now, with normal fulltime usage and plugged in, my converter is putting out 13.3 volts.

Batteries do of course fail. I had a pair of Interstate Grp 31 batteries that lasted six years, then supposed equivalent Walmart Everstart batteries that lasted all of 14 months, and now a pair of Crown GC2 that are a little over three years old.

[MFL]

All converter/chargers are not equal. Depending what you have, it may not go to float charge, 13.2volts, when plugged in 24/7. If the charger you have, maintains 13.6, or more, you may be cooking (overcharging batteries).

My battery is original, and 10 years old. Always plugged in, other than when removed over Winter. My converter/charger is a Progressive Ind smart charger.

Jerry

[way2roll]

Sounds like overcharging.