2 batteries??

[PToombs]

can we get some specs on the batteries? everyone i talk to about going to dual batteries say you have to get some crazy big alternator so you dont burn up the stock one. how does yous do? i really want to do this cause i have a plow that draws some amps and im going to have a rear back drag blade ran off of a electric hydraulic pump so im just wondering. thanks

With that much drawing on the batteries, you may need a bigger alternator to charge them back up. Or else run the truck enough to charge them before you shut it off for the night.

[ekk33]

I have two group 31's one NAPA, one CARQUEST

Biggest batteries I could find

BOTH 1250 CCA

[rwatford]

My biggest problem was my one battery was junk anyway! I had a friend donate me two almost new group 30s so I figure I may as well install both since I have them. I can build the battery tray no problem but I'm not positive on wiring them up. My old F350 was hot to hot and then to the starter and ground to ground and then to the chassis and engine for ground. Is this what I need to do?

[Richie O]

My biggest problem was my one battery was junk anyway! I had a friend donate me two almost new group 30s so I figure I may as well install both since I have them. I can build the battery tray no problem but I'm not positive on wiring them up. My old F350 was hot to hot and then to the starter and ground to ground and then to the chassis and engine for ground. Is this what I need to do?

Yes + to + and - to - . If you do it pos to neg then you will have 24 volts.

[BobS]

Because of my old GMC I hate dual batteries. Rule number 1, you always need to replace them in sets so you are already at twice the cost. And the problem is no two batteries are created or consumed equally. One will always respond to a charge faster than the other and over time that creates a leading and lagging condition causing the faster charging battery to constantly get slightly overcharged. Then as the battery starts to deteriorate it constantly pulls the other out of balance battery down as they try to equalize whenever the truck is not running. Sometimes switching battery positions can have a slight prolonged effect but normally it is not a significant justifiable gain. In the old GMC I thoughts of trying two large 6 volt batteries in series instead of two 12 volt batteries in parallel but I quit running the truck before the last set of batteries died. When I bought my Dodge I was really happy it only had one. Yes, I can understand the need for higher capacity batteries but I don't want to get back into that ordeal again.

[GO OVRIT]

I've got 2 Optimas in my 440 truck sideways on the stock tray. They fit nicely with the little half round tabs folded down.

[ccoxva]

Its fixed!!! I went to NAPA and bought the biggest DEKKA Commercial batt they had. 1300CCA. Also had some heavy guage out of an ambulance that I scraped and doubled the hot to the batt to give it that little extra. All good now thanks for the info.

[Begle1]

Because of my old GMC I hate dual batteries. Rule number 1, you always need to replace them in sets so you are already at twice the cost. And the problem is no two batteries are created or consumed equally. One will always respond to a charge faster than the other and over time that creates a leading and lagging condition causing the faster charging battery to constantly get slightly overcharged. Then as the battery starts to deteriorate it constantly pulls the other out of balance battery down as they try to equalize whenever the truck is not running. Sometimes switching battery positions can have a slight prolonged effect but normally it is not a significant justifiable gain. In the old GMC I thoughts of trying two large 6 volt batteries in series instead of two 12 volt batteries in parallel but I quit running the truck before the last set of batteries died. When I bought my Dodge I was really happy it only had one. Yes, I can understand the need for higher capacity batteries but I don't want to get back into that ordeal again.

Isolators and switches can remedy those situations and give you a system with much higher reliability, capacity, capacity and flexibility all rolled into one.

Two batteries wired in parallel like later generations do stock is a waste, I agree. But for bullet-proof reliability, do it like a boat and isolate the batteries. Run different things off each so that you don't drain down your starter battery with your headlights, retain the ability to switch to both batteries if one fails or you need twice the capacity, and charge them evenly through a big diode block.