Dual Batteries
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Joined: Oct 2007
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Dual Batteries
Has anyone ever mounted a second battery in their van? I have a 94 and I would like to get a second battery but I can't think where to put it or how to wire it. Any help would be appreciated.
George
George
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Joined: Aug 2007
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RE: Dual Batteries
I have 3 deep cycle batteries in my 89 b250. The Second and third batteries are under the body behind the drivers seat in a custom metal battery box I welded every where I could. I can Isolate the engine battery from the 'house bank' via a boat battery switch. This is wired to the oem battery connections over 2 awg cable. 12 foot lengths.
You want as heavy a gaugecable as you can afford. Use too light a wire and too much voltage drop will occur, making it difficult to fully charge the 2nd battery.
You could put an AGM battery inside the driver compartment as they dont outgas unless overcharged. I kept 2 flooded wet cell batteries inside for years but this is not a good idea. Regular batteries should be vented to the outside.
Batteries that are hooked in parallel, Ideally should be the same exact make and age.Otherwise the strong one is always being pulled down by the weaker, and the strong one will be overcharged by the alternator or other charger.
Adding another battery and regularly depleting itis asking more from your whole charging system and will expose any weakness.
I'm currently using3 wally world quasi deep cycly batteries. Although a deep cycle has significantly less cold cranking amps than a starting battery, one by itself has more than enough to start my engine.But Idon't live in the frozen north.I frequently will isolate the engine compartment battery, and after starting it, Iwill move my battery switch to both, and instantly the engine takes on a different tone as the alternator goes from pumping 12 amps at idle to 60. That 60 amp output reading is with my house bank only 7 to 10 percent depleted. If I drain the house bank to 50% then my battery monitor indicates the alternator is putting out 85 to 95 amps.
Most alternators are not designed to put out so much of their rated capacity for very long.
I'm on my 5th alternator since adding another battery, and then one more.
Buy the lifetime warranty.
You want as heavy a gaugecable as you can afford. Use too light a wire and too much voltage drop will occur, making it difficult to fully charge the 2nd battery.
You could put an AGM battery inside the driver compartment as they dont outgas unless overcharged. I kept 2 flooded wet cell batteries inside for years but this is not a good idea. Regular batteries should be vented to the outside.
Batteries that are hooked in parallel, Ideally should be the same exact make and age.Otherwise the strong one is always being pulled down by the weaker, and the strong one will be overcharged by the alternator or other charger.
Adding another battery and regularly depleting itis asking more from your whole charging system and will expose any weakness.
I'm currently using3 wally world quasi deep cycly batteries. Although a deep cycle has significantly less cold cranking amps than a starting battery, one by itself has more than enough to start my engine.But Idon't live in the frozen north.I frequently will isolate the engine compartment battery, and after starting it, Iwill move my battery switch to both, and instantly the engine takes on a different tone as the alternator goes from pumping 12 amps at idle to 60. That 60 amp output reading is with my house bank only 7 to 10 percent depleted. If I drain the house bank to 50% then my battery monitor indicates the alternator is putting out 85 to 95 amps.
Most alternators are not designed to put out so much of their rated capacity for very long.
I'm on my 5th alternator since adding another battery, and then one more.
Buy the lifetime warranty.
