# dual batteries



## packrat69 (Oct 13, 2012)

Hi, new guy here . I have a '63 jeep pickup with a homemade plow setup if I put a separate battery in the bed of the truck where the plow pump is and run a separate wire from the alternator would I still have to have an isolator or have issues overcharging the starting battery?


----------



## leolkfrm (Mar 11, 2010)

why not just tie the two batteries together with reg cables?...if you do, i would suggest 2 new batteries as thery need to be the same age for longevity


----------



## 2COR517 (Oct 23, 2008)

You won't need an isolator, and you don't have to worry about the batteries over charging. You do need to ground the second battery to the frame with a wire as large as the feed from the alternator, and both wires need to be sized for the max output of the alternator. You also need to run a ground from the pump to the second battery in the bed. This wire needs to match the size of the positive wire to the pump.


----------



## packrat69 (Oct 13, 2012)

thanks for the info I was hoping to avoid spending money on new batteries right now as the extra one I have is different from my starter battery.


----------



## packrat69 (Oct 13, 2012)

2COR517;1500425 said:


> You won't need an isolator, and you don't have to worry about the batteries over charging. You do need to ground the second battery to the frame with a wire as large as the feed from the alternator, and both wires need to be sized for the max output of the alternator. You also need to run a ground from the pump to the second battery in the bed. This wire needs to match the size of the positive wire to the pump.


thanks for the help ,I have a 105 amp alternator so I'm guessing I'll need something in the neighborhood of a 2-4 gage cable from the alternator to the battery a distance of about 8 feet.


----------



## 2COR517 (Oct 23, 2008)

Number 4 would be fine from the alternator to the second battery. You really should run a wire of the same size from the second battery ground to the alternator case for best charging results


----------



## forbidden (Dec 22, 2010)

And make sure you fuse the + line at both ends.


----------

