Adding a House Battery

TreeSeeker wrote:

TyroneAndGladys wrote:
On our RV we have two house batteries with one being under the hood and the second one in a battery compartment at the rear of the RV.

Are you sure those are both "house" batteries? Typically battery under the hood is for the engine and the battery in the back is for the "house." Sometimes they are both under the hood.

It is not good to install different types of batteries in parallel as the better one will be weakened by the weaker one and one is always getting overcharged and the other is getting undercharged.

Articles about RV electrical systems:

BATTERIES--AND OTHER ELECTRIC STUFF

The 12v Side of Life

Intro to Dry Camping

Battery Education

Yes two batteries under hood and one in compartment in back. Take cables off of battery on left side engine will not start. reinstall cables unhook cables off other battery engine starts. The only reason that I went to two different batteries is that if you want to check the water level in the back battery you have to remove the battery and that is a MAJOR pia and I did not want to spend the money for two AMG batteries.

I had CW put 2 6 volts in mine and an easy fill system have great power for dry camping. just another idea for you

TyroneAndGladys wrote:
On our RV we have two house batteries with one being under the hood and the second one in a battery compartment at the rear of the RV.

Are you sure those are both "house" batteries? Typically battery under the hood is for the engine and the battery in the back is for the "house." Sometimes they are both under the hood.

It is not good to install different types of batteries in parallel as the better one will be weakened by the weaker one and one is always getting overcharged and the other is getting undercharged.

Articles about RV electrical systems:

BATTERIES--AND OTHER ELECTRIC STUFF

The 12v Side of Life

Intro to Dry Camping

Battery Education

I would cut a piece of plywood to cover bottom of sheet metal compartment,( to distribute battery weight), put battery in a battery box , and secure battery box to the ply bottom with removable aluminum L shaped extrusions to keep it from sliding around in the compartment. Would be nice to have some sort of slide-out feature for checking fluid levels and cleaning connections if there is no access to top of battery.

pianotuna wrote:

tenbear wrote:
I don't know much about AGM batteries, but you probably have a lead acid battery now. It may not be advisable to have a lead acid battery and an AGM battery in parallel.

X2

On our RV we have two house batteries with one being under the hood and the second one in a battery compartment at the rear of the RV. The front battery is very accessible for maintenance the rear one is a pain since you have to remove the battery for maintenance. I did put a AGM battery in the rear and a standard battery up front due to the higher cost of AGM batteries. Four months now and no problems so far.

How old is the exsisting battery? The "problem" with two batteries, is the weak one will allways bring tahe strong one down! When changing the batteries allways replace both, with batteries built the same day, sequencial serial numbers would be the best! If you are thinking of going to two batteries, then buy two brand new batteries and install them as previously stated in this post. The two batteries will give you more amperage, for dry camping, and or to power an invertor. Good luck!

tenbear wrote:
I don't know much about AGM batteries, but you probably have a lead acid battery now. It may not be advisable to have a lead acid battery and an AGM battery in parallel.

X2

TyroneandGladys wrote:

tenbear wrote:
You should have some ventilation in a compartment that has batteries in it to let the hydrogen gas escape.

AGM batteries have little chance of a hydrogen gas explosion or corrosion. AGM batteries are AGM batteries gel and sealed batteries are not a type of AGM battery

I don't know much about AGM batteries, but you probably have a lead acid battery now. It may not be advisable to have a lead acid battery and an AGM battery in parallel. Maybe someone with more experience with AGM batteries can advise.

tenbear wrote:
You should have some ventilation in a compartment that has batteries in it to let the hydrogen gas escape.

AGM batteries have little chance of a hydrogen gas explosion or corrosion. AGM batteries are AGM batteries gel and sealed batteries are not a type of AGM battery

Hi,

Welcome to the forums!

This is what is balanced and best for twin twelve volt batteries.



As it often doesn't cost a dime more to do this, I think it is worth the trouble.

If you wish to understand the "why" surf here:

correctly interconnecting multiple twelve volt batteries

Others may say it doesn't matter--but unless there is a compelling reason to not optimize charging and discharging why not do it the best possible way?