Is the second battery beneath the passenger seat necessary or just useful?

[ThysVanLeer]

Hi, first post here and it's a complete Noddy question.
I recently bought an ex-RAC T32150hp 17reg BMT stop start van and am converting it into a little camper. I removed all the RAC wiring and am left with the second battery beneath the passenger bench seat. This is a MOLL efb+ 70Ah starter battery identical to the main one under the bonnet.
I saw that it had supplied power to all the RAC stuff which is now all removed, but is it necessary in any role to the function of the van or can I happily remove it and free up space. Because this second battery is a starting battery and not a deep cycle leisure battery I've fitted a leisure battery in the back of the van powered by PV on the roof. If this second battery isn't doing anything essential, could I simply keep it as a spare main starting battery?

 

[roadtripper]

It will be identical because it will be charged using a very basic split charge relay. It would still have been used as a leisure type role.

The MOLL batteries have known issues so when the engine one goes you'll probably want to replace with a better brand AGM.

You could consider fitting a DC-DC system and running 2 leisure batteries (one under seat, one in rear) as the higher spec Californias do, however if you didn't put the cable in then that's not as easy and may not help.

It's not essential to anything in the van but if you do remove it then you need to make sure the feed from the main battery is made safe and disconnected both ends. I'd leave in situ in case you decide to have engine charged battery in the future.

If it's a factory second battery system if you do remove it there are a few circuits that might be supplied from it you will need to move - possibly 12v sockets and towing. You have VIP membership so you can see the wiring diagrams

 

[Dellmassive]

You can use it for your 12v leisure electricals.

 

[Bigsidavies]

I removed the battery and used the feed to power my dc-dc charger using a nifty little plug and play relay/harness from travelvolts who no longer trades unfortunately.
I’m sure it would be easy to replicate that wiring.

 

[roadtripper]

I removed the battery and used the feed to power my dc-dc charger using a nifty little plug and play relay/harness from travelvolts who no longer trades unfortunately.
I’m sure it would be easy to replicate that wiring.

Most of the "standard" automotive electrical items use the 6.3mm blade terminals - so the blades of a relay or the "standard" fuses - which means if you make up appropriate leads you can pick up the feeds from the fusebox/relay plate.

Sadly my time here and travelvolts didn't cross but from what I've seen they went quite a bit further to have everything in a dummy relay.

If you feel worried by having wires sticking out of the relay plate you can probably depin the connector, insert your new lead, and make good with some heat shrink.

 

[Bigsidavies]

I’m fine with mine. It was plug and play 3 years ago and still going great. What I was alluding to is that there are people on here with the knowledge to create something similar to enable the OP to use the factory cabling straight to his dc-dc.

 

[roadtripper]

And I was trying to pass that knowledge of how to replicate it on.

 

[Bigsidavies]

And I was trying to pass that knowledge of how to replicate it on.

Aaah, I realise that now.