I'd go for a li-ion type over the older tech lead-acid versions. They work ok, but are more prone to leaking and don't like getting banged about as well as being a lot more bulky and a damn sight heavier.
The PowerAll type was one of the first out, I have a couple of those (one in the wife's car and one in the ute) and they are pretty bloody good. Will start a 3.5L diesel easily - from a 600A rated unit. You'd want the slightly larger unit for reliability with the 4.2L although I've started a couple with the unit I have so they do the job. Benefit is any way up storage, runs a cellphone etc and pick it up with one finger vs a fist...
Bookmarks