[Maverick101]

If i install a 2nd battery in my 94 vitara would i need to upgrade my alternator, and if so what alternator would i use.

[stewy91]

yes it would be better to upgrade your alternator and you can do a swap for the amp ford alternator.
Heres the link to it.

viewtopic.php?f=17&t=5529

[want33s]

You don't need a bigger alt.

Having dual batteries just means you have a double sized electricity tank and as long as you are using less power than the alt is supplying both batteries will get charged.
(I recommend a RedArc 'over-ride' dual batt controller.)

Fitting a larger EF 110A alt is a good idea when yours dies as it is larger capacity and cheaper.

[Gwagensteve]

Why do you need dual batteries?

Steve

[britvit]

I'm running dual batteries on a standard Vitara alternator without a problem. However I don't use it for big loads, just to run a fridge over night whilst camping. My set up is controlled by a couple of relays, while not perfect it is cheap, and reliable.

[squibby]

Also helps if you buy a proper charge controller for the second battery. If you just get a manual switch, then yeah at times your alternator will be charging two batteries at once. If you get a redarc or sidewinder or something they always allow the primary battery to charge first before linking the auxilliary battery, so generally you only ever load the alternator with one flat battery at a time with the automatic controllers.

[got_bar_work]

If ur only running wet cells in wouldnt bother with a charge controller they are not going to draw enough to max out the alt any way
I have 2 enersys extreams and they only draw 30-40a off my falcon alternator after winching