Auxillary fuse box wiring help + which batteries for dual battery set up?

I am looking to wire up an auxillary fuse box to a second battery.
Should I install a circuit breaker from each of the battery terminals to the fuse box? If so, what amp rating? 30amp?

I currently have one battery which is physically quite big and I don§t think I could fit a second one in there. I would like to buy two and have been looking at the Optima Yellow Top. They are quite expensive so are there other options I could look into?

Cheers

I fit two full size batteries in my seatbox.

Currently mines wired directly to the starter battery but will be wired via a Durite VSR.

Aux fuse box wired into the second batt. If you fit a fuse should be 150amp.

What will you be running off the aux fuse box?

nobber said:

What will you be running off the aux fuse box?

Click to expand...

Very ocassionally a fridge, otherwise usb phone charger, some work spotlights. Possibly an inverter in the future

mikerajjers said:

Very ocassionally a fridge, otherwise usb phone charger, some work spotlights. Possibly an inverter in the future

Click to expand...

Its difficult to say then, because you also need to spec the cable as well, without knowing what you will be drawing through it you may as well spec it as high as you can, just keep the fuse rating lower than the cable, the job of the fuse is to protect the cable. Keep the fuse as close to the battery as possible, the fuses in the fuse box will protect the cables on the other side of it, so the only things really that can cause damage is the fuse box melting and shorting out on the battery side or the cable getting damaged and shorting out, if the fuse is right close to the battery side it should be good..

You need to put a split charge relay in to direct charge from your alternator - there are many different set ups. I use the national luna one, which is needlessly expensive but works well.

https://www.expedition-equipment.com/product/national-luna-split-charger-kit/

Copy the set up in the picture 2 using the same rated fuses and cable and you won't go wrong.

I use a blue aux fuse box which is a nice piece of kit - some people use a disco fuse box as they are cheap.

https://www.mudstuff.co.uk/products/electrical/sockets-and-plugs/blue-sea-fuse-box.html

Battery wise optima is what i've got at the mo