Outer Limits 4x4 Board

Am thinking of setting up dual batteries while my truck is off the road getting some engine mods. When it's done i'm going to have limited room in the engine bay, i'll never fit a full size n70 battery.

I'm wondering if any battery guru's know what sort of minimum CCA I should look at for a basic starting/ignition battery?

My engine is a 4L V8, all other accessories will run off the DC battery.

I have a low profile euro style battery spare from the wifes car, but it's only 480cca, is that too small?

Stolen from me3@......

Odyssey PC925 - Small Start Only battery
These small expensive AGM’s are made to deliver spectacularly high starting currents from a small battery. If you don’t have room for a Dual Battery setup, or want to go to a Triple setup, then one of these should be your start battery. 925A for 5 secs, 620A for 10 secs - it starts my 1HZ with ease. I’ll update after a -5 winter day, but for the moment it works fine. I didn’t want a huge start battery that never used more than 5% of it’s capacity and wanted to be able to go to a triple setup later.

620a should kick over you 1UZ.

Thanks mate, they are nice and small. In fact I don't think i'd have to relocate it as planned, apart from moving it a few inches to the side to make way for......

The rest is secret

Looking at the peak cranking amps of these AGM batteries they're amazing, even this tiny thing claims 690PCA for 5sec

http://cgi.ebay.com.au/STINGER-SAME-POW ... dZViewItem

I have a hard time picturing it starting a V8 though, surely they're too good to be true

I'd go in the 600s for a Cold Cranking Amps which are the main ones to look for the ones on ebay are only 390CCA which is good for a small battery but ....