One system, two independent batteries?

[Chromosome17]

Afternoon,
Please could someone me advise what I need to buy to achieve the following.
I'll have a 20w pannel and to keep my car battery charged =(12v 77a type 096) but also an old 70a type 069 battery separate to power my lights etc in the garage.
I don't want any draw from the garage lighting on the car and don't want to system trying to balance the 2 batteries.

Would one of the dual battery controllers that show up on Google for about £20 achieve this and then just connect my garage lighting rig to the old independent battery without effecting the car?

Many thanks. Ian.

 

[littleharbor2]

That or an A B switch.

 

[Chromosome17]

OK thanks, I'll have to look at the a b switch. I'm not sure that will fit with a fire and forget setup I need

 

[12VoltInstalls]

setup I need

You could use an automatic battery isolator and you need a panel much bigger than 20W imho

 

[Chromosome17]

It's just to maintain and unfortunately 20w pannel is pushing the maximum size I can fit.

 

[pollenface]

Voltage sensing relay ... as found in vehicle dual battery systems.

voltage sensing relay 12v - Google Search