Question about leisure battery and split charge relay

[Migz]

Hello, im hoping you can help me with a quick question.

I'm planning on installing a system into my Hyundai Accent 1.3 but HO alternators are far and few between so im going to have to rely on batteries. I can only buy from eBay and i can't find any proper car audio batteries in the UK and i cant order from Europe or USA as posting to UK is normally more expensive then the battery itself, so im thinking of getting a few leisure batteries.

My first question is that are these batteries any good for starting the car? As I'm thinking of replacing the starter battery with one, and having another 2 in the boot.

My second question is how would i go about split charging the batteries? I have a split charge relay but the cables it takes are tiny, can't be more then 12AWG. Their is no way these would carry enough power from my alternator to my rear batteries to keep them charged at all.

Basically I'm either going to have one leisure battery up front, with 2 leisure batteries in the rear, this is so that they don't feed off each other and drag the voltage down.

Or just have three leisure batteries in the rear with a split charge system so that i can keep the original battery in the front for just car electrics, and have the three in the back for the system.

My system is probably going to be around 3000wrms, maybe a tiny bit less at first.

[Guest]

no point in using a "split charge relay" unless you plan to play your stereo with the car off. with one of those relays, you'll drain your back batteries constantly and your alt will have to struggle so hard to try and recharge them (alts hate recharging dead batteries, and it shortens the alts lifespan too)

its best to just wire all your batteries together without any sort of relay inbetween them.