House Battery getting hot

[TEO]

I store my 2018 Baystar in an rv garage at my mother's house, the other day she told me that there was a weird smell in the garage, today I dropped by and opened the door to the house battery tray and you could hear a hissing. Pulled the tray out and of the four Interstate group 24 lead acid battery's the second one was very hot and you could see moisture on the top of it. I unplugged the Inteli-power battery charger.
I have owned this for about 10 months and the battery's don't have a date sticker on them so unsure of the age, could be OE.
Couple questions,
Is it OK to leave the Inteli-power on when in storage?
We don't boondock so do I need 4 battery's?

 

[Richpatty]

I would check the water first…. But I am betting it is time to replace them….especially the one that got hot.

It is normally ok to leave a charger on, but it depends on the settings and keeping tabs on the battery maintenance.

 

[Phillbo]

Start from fresh and replace them. Yes you need batteries, even when plugged in to shore power the batteries provide power for stuff like lights, water pumps, fridge / ac / water heater control boards.... group 24 sounds small. maybe just invest in a singe 100aH lithium since you don't need the max storage. They don't get damaged if drawn way down of when an "inteli" anything becomes not so "inteli" and tries to cook them.

 

[TEO]

I would check the water first…. But I am betting it is time to replace them….especially the one that got hot.

It is normally ok to leave a charger on, but it depends on the settings and keeping tabs on the battery maintenance.

I installed a battery watering system right after I got this and topped them off about 2 week ago, so it shouldn't have been low on water.
I will have remove a barrier to get a better look at the charger, can't see if there are settings to adjust.

 

[T’sOVR&Explore]

Four lead acid batteries is a lot of expense to periodically replace and a lot of weight. For about 25 years, I suffered along with maintaining a series pair of flooded lead acid 6 volt golf cart batteries, wired in series so they could stay balanced up while being the 12 volt house batteries in a Chevy P30 motorhome chassis. Bought new ones every 5 years or less, They were 115 to 140 bux each back then (last bought in 2010). once in a while, we got one that seeped acid from the git go, dangit!

Fast forward to 2025, our current (now a trailer type) camper got the LiFePo4 battery upgrade. Bought a 300 amp hour one for about 280 bux from Amazon, bought a 20 amp charger suitable for Lithium, put the battery in a Noco group 19 plastic battery box with one of those 50 amp lever style breakers screwed to the end of the box and now, no water to deal with, likely 10 year life cycle, weighs what one group 24 lead acid did, works great. We don’t deep discharge it, so the 20 amp charger is enough to bring it to full charge fast enough.

As the other poster suggested, the 100 amp hour Lithium might be enough. We also have one of those, in another group 19 Noco battery box (and use a loose lay 10 amp Lithium service charger), that we ride on the floor of the back seat in the crew cab truck that pulls the trailer. The 100 amp hour battery serves our piezo picnic day trip cooler so that the truck batteries are not involved. Weighs maybe 25 pounds.

Lithium will free you from the lead acid rig-a-ma-roll. Not really more expensive than multiple lead acid if you can do the upgrade yourself. Hope you get to a good solution!