Dual batteries--Ground location? (1 Viewer)

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Since I installed my dual battery system I have been getting lots of oxidation(green on the batteries)? The primary battery was grounded to the engine block so I ran the 2nd ground to the same location. I used 2/0 wire. Anyone use a different location? I also have a hum in my speakers on start up now.

Thanks
 
I grounded mine at the engine block along with the primary, and to the chassis in the symetric spot as the primary battery.

I've got no hum and no problems. By any chance are you mixing batteries, either by type or by age/condition? You may be cooking them.
 
I grounded mine at the engine block along with the primary, and to the chassis in the symetric spot as the primary battery.

I've got no hum and no problems. By any chance are you mixing batteries, either by type or by age/condition? You may be cooking them.

I am mixing a deep cycle/start and a plain start battery. I installed a marine charging system that is set for the particular battery--down the road I plan on dual deep cyle/start. Where is the chassis ground you are talking about?
 
Ground battery negtive terminals to the alternator casing directly.
 
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I am mixing a deep cycle/start and a plain start battery. I installed a marine charging system that is set for the particular battery--down the road I plan on dual deep cyle/start. Where is the chassis ground you are talking about?

Chassis may not quite be the correct word, but if you look at the stock battery it's got one lead going to the engine block and another lead going to a screw on inside of the front left quarter panel. I duped this setup for my second battery, but on the opposite side.

If your charger is smart enough to know your battery and charge by type, temp, etc, then I'm surprised you have a problem.

Are these normal flooded batteries?

Do you have a schematic? I wonder if there's something wrong with the charger. I associate the green corrosion with overcharging and acid bubbling out, but I could be wrong.
 
Chassis may not quite be the correct word, but if you look at the stock battery it's got one lead going to the engine block and another lead going to a screw on inside of the front left quarter panel. I duped this setup for my second battery, but on the opposite side.

If your charger is smart enough to know your battery and charge by type, temp, etc, then I'm surprised you have a problem.

Are these normal flooded batteries?

Do you have a schematic? I wonder if there's something wrong with the charger. I associate the green corrosion with overcharging and acid bubbling out, but I could be wrong.

After reading this I realize I made an error. I rerouted all my wiring--I have a marine grade positive post on the fire wall. I cut the wire that grounds the original battery to the left quarter panel. Heading out to try this...... My water levels are pretty full still. Yes these are flooded batteries--one is a marine dual purpose from Costco.

Like Grench I used Anchor tinned terminals, connectors, and heat shrink. Also used a marine grade battery switch and charging system. Our cruisers are rather common to cruising yachts.
 
Drove to work today "HUM" free. I was dreading trying to find the bad ground...... Turns out grounding both batteries to the quarter panels solved the problem:cool:

hopefully this solves the "green" build up as well.
 
I haven't noticed any hum, but I did upgrade the 8ga body ground to 4ga when I did the dual install. Still only on the DS though. Good catch on adding more grounds.

I agree. These ARE like yachts. Not -quite- as expensive, but I use marine stuff frequently on it. Especially electrical components.
 

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