Simple leisure battery system.

[andyh]

Firstly thanks for reading. Having spent hours reading through the myriad threads on here on this subject, I can imagine you're sure there isn't a question that hasn't been asked (or answered). However...

I'm planning on fitting a leisure battery, which will feed a secondary fusebox up front. All I'm planning to power from this is a unit of 4 x 12v sockets, unit fused to 10A, and the stock westy interior light. All I'm going to run from the 12V sockets is a couple of usb phone chargers, 1A each, and a stereo, guessing at 4-5A.

So the questions. Firstly, am I right in thinking that 17A cable, (fused to 15A), is more than adequate for the battery to fusebox run?

Secondly, what size of relay do I need to do the switching? I see that JK have a cheap set up here,

http://www.justkampers.com/092-vag-227-dual-charging-kit-for-all-vw-models.html" onclick="window.open(this.href);return false;

and I seem to comply with the "up to 15A" condition. BUT, and this is where I regret being relatively clueless on electrics, although 15A is the most I'll expect to draw from the leisure battery, how much current may flow from the main battery to the leisure battery through the relay during charging?

Which leads handily to Q3; what cable and fusing do I need to use between the 2 batteries and the relay? The standard battery cables look pretty meaty, do the other cables need to be of similar dimensions? I've seen how-tos suggesting that 35A cable and 30A fuses will suffice.

And finally, honest, what does the expert panel feel about the merits of a Smartcom voltage sensitive relay,

http://www.brocott.co.uk/split-charge-relays/intelligent-self-switching-split-charge-relay-12v-30amp-h78-1.html" onclick="window.open(this.href);return false;

against a relay switched by the charge light feed from the alternator?

Thanks again for your patience, all help very gratefully received!

 

[andyh]

A small bump, still waiting for the electrics gurus to come along!

I've been wondering about this a bit more, and regarding the wiring between the batteries it occurred to me that battery chargers don't use particularly thick cable, but then I assume that the charger regulates how much current it puts out? So still mildly confused...

 

[*Sam*]

Would a Zig Cf8 or similar not provide you with what you require and a split charge system and 240v hook up etc.

 

[bigdaz]

For a simple system you just need a relay with in line fuses the leisure battery wont be cranking the engine so the sort of spec you are talking should be fine.
The smart relay doesn't require a trigger from the alternator so is simpler.

Sent from my GT-I9305 using Tapatalk 2

 

[simo]

I have just fitted a Durite smart charger to mine, main batt to charger - charger to leasure batt and an earth for the charger, simples :msn4:
I used 10mm 12v cable rated at 70amps and an inline 60amp fuse next to each battery!

If you want more details on the parts let me know