Campervan Leisure Batteries retrofit installation questions

Radventures · Jul 4, 2018

Hi there,

I have a setup at the moment involving a leisure battery/inverter. I am replacing the single battery with 3 batteries. What I'm wondering is will this mess up my previous calculations re wire/fuse sizes? I'm very confused by the information I've read online. And to connect the two other batteries do I just add them like this:

Hope you can help - many thanks!
Scott

westward10 · Jul 4, 2018

Is your single battery the same voltage as each of your three new batteries.

PEG · Jul 5, 2018

Hi bud, they should be connected in parallel,as diagramish.

Your issue may be the potential current they will supply,and the capability of the conductors and fusing.

Another thing to watch,is how you are charging these batteries.

If they are all identical age,size and condition,a charging system can be configured to work ok. The fact you need three,may be an indication of intended current usage,and you need to factor the amount of current,they will attempt to draw,if depleted.

I trust,you do not have a 1960's split-charge relay....

Radventures · Jul 5, 2018

Thanks for the replies chaps! The single battery I am doing away with. I have three new 110ah amg batteries and am using a battery 2 battery charger. The charger is currently fused with 50amps on the in and after referring to the manual, have realised I should have fused the out (I assume also 50amps?!). I missed this before as I had an auto electrician come in and check I was doing things safely and he never mentioned it, so maybe it's unnecessary?

The max wattage I can use through the mains is 500w as this is my inverter's capacity, but in reality I probably won't use anything more powerful than my laptop (120w).

I've been looking into potential current. Am I right in thinking if the batteries are identical, the current will be the same (ie a 1/3 from each battery)?

(reference: "What does change is the total potential energy in this circuit. If you double the battery count, the total current sourced to the LED will be unchanged, but the current supplied by each battery will be 1/2 of the total. Because the batteries are supplying half the current as before, they will last twice as long.")

PEG, you mentioned that they will draw current when depleted. I can't find anything on this, would you be able to elaborate? Thanks in advance!