Anyone done a dual battery upgrade?

[Ice98]

Looking to purchase the cables and battery to add a second battery

Planning on running an amp off the second battery and linking both with an isolator between so that the starter battery cannot be drained when using the secondary...


Either that or running everything but the starter off the main batter, and re-routing the starter to the secondary battery so it is the only thing being run off

My main question is what the lengths are on the "Big 3" cables (power, ground, etc) as well as what length it takes from the left to right and any other cables I may need, I would buy a kit but they are stupid-expensive and I can do it for less than half the price building my own cables and buying welding cable and connectors

 

[Lion77789]

I`m planning too

 

[zaden]

I did. replaced stock alternator with H/O 250 amp running the charge cable (0awg) to the rear battery then back to the front also used 0 awg ground to connect the two batteries. This allows even voltage to the batteries as you loose some with the run of wire. I use 300 amp fuses at the alternator and again at the rear battery to catch any shorts. Used 0 awg ground wire running from negative battery post to back of alternator also upgrading existing grounds. Last upgraded the power wire to main fuse/relay box to allow more current to flow.