[peobryant]

You should be fine with one battery.

 

[Philip]

One battery is fine.

I used a 800 CCA battery for about 7 years. It finaly died in January of this year.

 

[BuffaloLake]

I've mounted an isolator before. The reasoning for going through the alternator is that your only pulling power when the engine is running so you don't kill the battery. If you don't want to tap into the alternator, use a relay instead of the isolator. You can run power directly from the battery (fused of course) to the relay, then use an ignition powered source to activate the relay. The relay will be much cheaper as well.

 

[kingof_boggle]

where do you live? i am a newbie so i can't say for sure but i know with my last truck (gas) i had a new starter, alternator and 800CCA battery and a few times last winter it was 100% dead. same deal with my last TD jetta-even had new glow plugs, bus bar, 700 cca battery etc.plugged in and still dead in the really cold winter nights at the cottage (@ 300km north of Toronto). this will be my first year with one of these trucks and i also hope i dont need an extra battery.

 

[90powerram]

I just replaced the battery in mine - it's a group 31 with 1150 cca's for about 90 bucks. The only reason I'd ever put two in there is if I run an isolator and a second battery for running the camper.

 

[wjones]

Im using a sure power 1 input 3 output isloator. Its not hard to grab the wire coming off the alternator, it goes right to the main battery, run it over to the isolator input then use the other end of the wire to charge the battery from the isolator output.

I dont really like the relay trick, if your aux battery is low, when you try to start the batteries will attempt to equalize and drain off the starting battery.

 

[Rattletrap]

You will be fine with one battery. Mine is 1000/850 amp. Our battery box is an odd shape, the battery fits best if it is one of the 13 inch long types.

If you want the ultimate, look at the Kinetik HC2400. It fits the box and has 1700cca. Dry cell, deep cycle, should last 10 years. A bit pricey though. You can usually find it at $300 or so.