Dual Battery Setup Discussion

buggman

buggman

Do not touch the trim!
Here's the place to discuss the Dual battery/ battery isolator mod.

If you have done the mod, let's see the details of your setup... what parts are you using, how you made the connections, where you mounted the 2nd battery, etc.

This should be a pretty interesting topic as I'm sure many of us have thought about doing the mod.
 
I haven't done it, but if I was, I would relocate the air cleaner and get a 2nd Ranger battery tray. To connect it, I would use the oem style cables from an E or F series Ford diesel. I think a 120 amp alternator would be minimum.
An effective air cleaner would be the hard part. I personally don't like the cone style aftermarket ones. Maybe some sort of flat panel in front of the radiator with hose connecting it up. Bonus points for the extra 5hp from the ram air effect.
Option 2 would be put the air cleaner in the wheel well.
 
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Almost four months and then two people making posts but neither have dual battery setups.

One thing to remember, when doing this mode get two new batteries… even though they will be isolated they will take a charge the same way.
If they are close to new or the same age then it should work ok but think new alternator, new batteries and new cabling to include a new grounding system and make sure the cabling is sized correctly for the current flow (amperage).

While you are at it… here it comes, make sure to run a new ground from the battery to the frame, also from the battery to one of the starter bolts and a new ground wire to the engine and a separate connection to the alternator housing and always get to bear metal for the connections.

This all sounds like extra work and it is but if you are doing a dual battery setup you want good power and also a good return path for the current to flow.
i.e. “The Path of Least Resistance”, this makes for better charging and the most current making it to your accessories

Maybe this will wake up some people with dual battery setups so I can learn what they have done.

Post up guys !
 
One thing to remember, when doing this mode get two new batteries… even though they will be isolated they will take a charge the same way.
If they are close to new or the same age then it should work ok but think new alternator, new batteries and new cabling to include a new grounding system and make sure the cabling is sized correctly for the current flow (amperage).
While you are at it… here it comes, make sure to run a new ground from the battery to the frame, also from the battery to one of the starter bolts and a new ground wire to the engine and a separate connection to the alternator housing and always get to bear metal for the connections.


Good points. I guess I assumed most of that would be understood by using new diesel cables. The last F350 diesel I worked on did not have isolated batteries. The batteries as a matched set is important. Although you "can" get by with one new one if you existing battery is tested and verified good. The batteries are not always the same size. Check the battery specs for diesel Ford vans. The right battery is a different size than the left.
I wouldn't think you need a new alternator, just a good high amp one.
Your truck won't draw any more amperage than it does with one battery. It will just be able to have twice the capacity. Instead of cranking for 10 minutes it can crank for 20 minutes. Unless you add a winch etc..
Make sure you wire the batteries in PARALLEL not series. 24v will make your truck start fast one time.
Your suggestions are correct to do it right the first time, but be prepared to spend some money. I personally would scavenge a junkyard to find oem Ford cables. The diesel cables are plenty heavy duty and already molded together for dual batteries.

My comments come from working in a school bus garage for 20 years, where we had over 100 dual battery vehicles. Real world fleet maint. may be different than customizing a Ranger.
 
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I guess I am the man of the obvious.
I have mentioned the new ground wires and the additional starter/alternator grounds on a few other occasions and mention “here it comes” so not to get an fur flying.
I think there is something called the Big 3 too but the big thing is do it right and you will not have to do it again, at least not too soon anyway.
 
I am guessing by Big 3, they mean the 120 amp 3G Ford alternator. It was an option on Rangers, and fairly common on Explorers. It's a 20 minute bolt on upgrade. I had to change the belt also. Some may not. I bought a used 3G 120amp and a rebuild kit for it from fleabay. I have an 03 with a serp belt.

stolen from a thread on another board...

Definition: the "Big Three" upgrade means improving the current capacity of three cables: 1) alternator positive to battery positive, 2) battery negative to chassis, and 3) engine ground to chassis.
 
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Really had something to do with wiring.

To me putting on a 120 amp alternator would be OK if you were running a 50 amp alternator but most are 90 +.
190 or 200 amp setup is the way to go IF you are going to upgrade, go big sort of thing.
 
Scrambler82 said:
Really had something to do with wiring.

To me putting on a 120 amp alternator would be OK if you were running a 50 amp alternator but most are 90 +.
190 or 200 amp setup is the way to go IF you are going to upgrade, go big sort of thing.
Click to expand...


I agree except for the fact that a 120 amp unit can be bought and rebuilt for about $60.00 total investment. A 200 amp aftermarket is several hundred dollars. Personally I think 120 amps is more than enough for most needs. 200 is overkill unless you have a specific need for it. I don't have a huge stereo or winch/plow. All I am looking at is cold cranking amps in PA winters. 120 amps will keep those batteries charged fine.

With a rebuilt 120 amp, used cables/battery tray, and an additional battery I can have a working dual battery setup for approx $200.00. I can always buy 2 new batteries when these fail and upgrade the alternator IF I need to. I agree to go big and all new if you have the cash to go that route. I personally don't have the $1000 to do that.
 
Wow, three months, where does time go.

Money, that is big problem now-a-days, good jobs are not there any more.

I never stop to think about the money, not that I have a lot but just because I like to do it once and forget about it and yes that means new parts.

Under the Ranger hood is tight, fitting in the duals is tight going.
Wondering how far apart the two batteries can be ?
 
If you're going that route, you could mount them both in the bed. It would give a little better weight distribution. It would also simplify the cables. Ground them in the back and run one cable to the starter.
 
Shawn said:
If you're going that route, you could mount them both in the bed. It would give a little better weight distribution. It would also simplify the cables. Ground them in the back and run one cable to the starter.
Click to expand...

That is actually a good idea but I was just asking, not sure what is in my future for batteries.
IF I did the dual batteries in the bed setup, I would run a positive and negitive cables to the front, maybe an HD stud setup and all the electrics would come off of those points.
GROUNDS, that's another ball game. There would be multiple points, at least one inside the body and some on the frame but isolated from the frame. All connected back to the battery setup, like you would have with a Fiberglass Body.

Sorry, got carried away... again !
 
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