new leisure battery

[2CRAZYCAMPERS]

Hi any suggestions, old leisure battery dead need to replace, i would like to install two 125ah battries inline but dont have room in battery compartment.
I could bring the lead inside motorhome and store under seats in living area, but my concern is that the battries give of fumes and to me this spells danger! (is there a battery that doesn't give of fumes)?
As anyone got good advice or do i just replace with a 113ah the largest i can fit in compartment.

 

[Lorry Ball]

Most new battery's are sealed for life
so long as you don't overcharge them and make them boil, there should be no problems charging from the alternator or solar panels
I have 2 starter battery's under my drivers seat (24v) and 2 leisure batts (24v) under my bed, and charge them at about 6amps with no problems, with a mains charger when hooked up, via my 1500w inverter/charger.
The only way you would get fumes is if you heavily discharge or charge them at a high amperage, making them boil
i.e. possibly using a Microwave for 30+mins with one 12v battery
go with 2 leisure battery's connected in parallel, they will be sharing the load, so even less of a problem...

Lorry :drive:

 

[Deleted member 3011]

There is no battery that won't give off fumes under all circumstances, and sensible recommendations are to install them in a compartment that is at least partly sealed from the living space and ventilated to the outside.

That said, AGM and GEL batteries are regarded as the safest types provided the charging current is kept at the low end of their recommended range and many MH manufacturers mistakenly believe that it is perfectly OK to install them anywhere they please.

Mine has a low-maintenance Calcium battery as the starting battery under the drivers seat and a gel house battery under the passengers seat and a second dealer supplied gel under the dinette seat. Certainly far from ideal, but a major problem to do much about it.

Just don't buy a normal flooded-cell battery with screw caps with a hole in them. They DO need proper sealed enclosure ventilated to the outside.

 

[Byronic]

I've seen quite a few vans with batteries in underbed lockers with perhaps a vent in the front panel ie venting to the van interior,suggesting while it's not exactly good practice there's little risk.
My two start batteries are under the drivers seat are sealed to the van interior, but with a small vent slot in the floor, yet everyone knows the gasses given off by a lead acid battery are lighter than air, thats Mercedes for you!! Obviously it must be more a theoretical risk than real, Mercedes must assume enough air gets in thru the slot to purge the space.
Worth rembering cheap unregulated chargers if left on after giving a full charge will eventually make a battery boil giving off dangerous gas volumes.

 

[The Grand Wanderer]

Hi any suggestions, old leisure battery dead need to replace, i would like to install two 125ah battries inline but dont have room in battery compartment.
I could bring the lead inside motorhome and store under seats in living area, but my concern is that the battries give of fumes and to me this spells danger! (is there a battery that doesn't give of fumes)?
As anyone got good advice or do i just replace with a 113ah the largest i can fit in compartment.

All my batteries are inside the van, engine battery underfloor in front of passenger seat, leisure batteries under sofa in saloon. All of them are good quality lead acid batteries and all have a vent tube attached leading to the outside, none of the filling caps have holes in them. The van is a Frankia based on a Mercedes chassis. I think that as long as you get proper leisure batteries and vent through a tube you will be fine.
Wanderer

 

[2CRAZYCAMPERS]

Thanks for for your advice, dont know about cheap battery chargers the only charger i use is the alternator from the van while driving and the 240 volt connection lead (hook up) given with the van from new dont think they would (boil) battery, would they?

 

[Byronic]

The onboard 240v charger is designed for being permanently left on. As is of course the alternator designed to charge all the time the engine is running. At times though batts are detached for one reason or another and sometimes charged up with unregulated crap chargers and left unsupervised beyond a full charge, and they sure bubble away producing a surprising amount of gas.