How To:Dual Battery/Inverter Setup

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OneOneNiner

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Main batt. pos. and neg. with lugs,shrinkwrap,and jacket
Now Yellow Top =)
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Breaker stashed behind Provent.
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HD marine switch "1,2,all"and volt meter
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1500 w. inverter under rear driverside seat"with enough wire to sit on floorboard,if seat is down"
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Rear mounted bluetop"again,appropriate lugs n shrinkwrap"+250A.12V. circuit breaker
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front wire chase
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rear wire chase
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Main batt. positive to switch #1
Main batt. negative to rear batt. negative, off rear batt. negative to inverter negative
Positive of rear batt. to switch #2
Switch #3 to positive of inverter

Switching to 1 runs inverter during driving
Switching to 2 runs inverter when engine off"to the back batt"
Switching to "All" when driving,charges rear battery
Switching to "All" when engine is off,runs inverter,and or radio,x-tra long"through the night with fan"
Also "All" during dead main batt. is an instant jump-start

15 foot 4C. #2 S.O. cord "stripped out of jacket"
H.D. Perko marine switch
8 #2 lugs "you'll need to borrow crimping tool"
shrink-wrap at all lug terminations, wire casing"under the hood"
Blue-top Optima with batt. box
Inverter "min. 1500W." wish mine was a lil bigger
Voltage meter "optional"
2- 250A. 12V.DC breakers@each Batt.Positive
Enjoy...
This is a tried and true system,used it for years in my 56,and 85 ford trucks
 
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kb0nly

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Basically what i had setup in my S10 but instead of the marine switch i had a continuous duty 200 amp relay that was ignition switched and i also had a bypass switch that let me turn on the relay regardless of the ignition position. With that setup i could do the same thing as yours, just the rear, tie them both together running or not, etc.. It was a single pole double throw switch, up would bypass the ignition switch with power from the front battery, down would bypass the ignition switch with the rear battery, and with the switch in the center off position the relay was just ignition switched. That way no matter what battery was dead i could still manually flip the relay over.

The switch and added voltmeter is neat though!

Did you bolt down the battery box in the rear or use those metal pieces that you screw down and run the strap through?
 
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twack

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If you noticed the strap in front of the box;well,I cut a small slit in the carpet on each side of the battery box and ran the strap under the carpet.
Been holding great for a long time now
well not to (deadhorse)... in a rollover siuation it will easily rip that carpet and turn into something deadly, i come from drag racing so its a little more extreme cases but thats the logic behind a good tie down
 

OneOneNiner

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The wire(coming from beneath carpet run into bottom of batt. box via groment)will keep it from going too far,strap just assists.
Think mabe the battery box will fit inside of a battery tray?
 

speedracerbubba

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from the first result on google search:
"A good starter will normally draw 60 to 150 amps with no load on it, and up to 200 amps or more while cranking the engine. The no load amp draw depends on the rating of the starter while the cranking amp draw depends on the displacement and compression of the engine. Always refer to the OEM specs for the exact amp values. Some "high torque" GM starters, for example, may have a no load draw of up to 250 amps. Toyota starters on four-cylinder engines typically draw 130 to 150 amps, and up to 175 amps on six-cylinder engines."

It looks like big diesels can draw in excess of 450 amps.
 

kb0nly

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The wire(coming from beneath carpet run into bottom of batt. box via groment)will keep it from going too far,strap just assists.
Think mabe the battery box will fit inside of a battery tray?

Only the carpet is holding it then?? Projectile in a crash!

Oh i noticed the comment about the fuses, i wasn't going to say anything but where are the fuses located?? You should have the second battery fused right at the battery otherwise the entire length of the positive cable from the battery up to the switch or fuse location is unprotected, i've seen some really nice car fires where they put the fuse for a large stereo amp at the amp instead of the battery end of the cable at the battery.

Rule #1... Its only protected AFTER the fuse, so think about the amount of unprotected wiring you have before the fuse.
 

kb0nly

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The wire(coming from beneath carpet run into bottom of batt. box via groment)will keep it from going too far,strap just assists.
Think mabe the battery box will fit inside of a battery tray?

I wouldnt bet on it... That battery weighs enough that in an impact the wires will just tear apart, and the plastic box will just break and shred... I have seen it happen with trunk mounted batteries before. Usually the cables pull out of the lugs or the terminal even breaks off the battery and leaves the cable intact. Doesn't take much to snap a post off a battery, i can do it with a pipe wrench and some lateral force, think of the forces involved in an accident.

I would just make up two brackets to put on the floor, under or on top of the carpet doesn't matter, and then bolt them to the floor and slide the straps through them and around the battery box. Usually those boxes come with some plastic or metal hold downs for the strap, but the plastic ones ain't worth crap, i broke a few sets from the battery box weight shifting around on the boat i used to have.

Or you could even just bolt the battery box down with a couple metal straps inside to spread out the load of the bolt heads and put the strap around underneath the box. Basically just bolt the sucker to the floor regardless.
 

kb0nly

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Do you think 40amp is enough to crank a dead battery if the main battery ever dies?

You don't always need the second battery to crank the engine, it merely acts as a charger, you connect the batteries and wait a while, this lets the second battery charge the main battery.

If you need second battery starting capability then go with larger fuses or a resettable circuit breaker like so...

That's also why i went with the 200 amp continuous duty relay for a two battery setup, they can be tied together and with large enough circuit breakers you can have a two battery starting.
 
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kb0nly

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Get the changes made? Just curious if you got it all done... I'm seriously considering a second battery on my KJ, probably won't get it done until next spring though. I wish i had taken all the bits out of the S10 i had before i sold that so i could re-use them... Wasn't thinking when i sold it.
 

OneOneNiner

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There were so many to choose from.confused2.gif
Just ordered the 250A inline breaker,so I wont have to crimp any more lugs on.
They are 4 1/2" long,and I hope that I can cram it in the batt box.
I'll post pics when I finally get around to install.
 

OneOneNiner

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Finally added the breakers,updated pics in original post.
Feel better about the system knowing it's safe.

JL,does this qualify me for my Yellow Belt?
 

OneOneNiner

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Can list where you got the parts?

No problemo Joe.

1500 w inverter and Optima Blue Top-Sam's Club
Perko 1,2,all-Local Marine and Boating store
4conductor#2 SO,#2lugs,shrinkwrap-Local Electrical wholesaler
250A 12V. circuit breakers-Online(only one or two that sell'em)
Voltmeter,wire casing-Autozone
:cool:
 

Kugellager

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@kbOnly

So have you done any night wheeling with all your lights on since you did the dual battery setup?

I have 400w of lights on top and notice if I have all of them on with my headlights and fog lights there appears to be some slight dimming of my lights after about 1.5 hours of everything being on while driving.

I am considering the dual battery setup with the 160 amp alternator as a soution to this issue.

John
];')
 

kb0nly

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@kbOnly

So have you done any night wheeling with all your lights on since you did the dual battery setup?

I have 400w of lights on top and notice if I have all of them on with my headlights and fog lights there appears to be some slight dimming of my lights after about 1.5 hours of everything being on while driving.

I am considering the dual battery setup with the 160 amp alternator as a soution to this issue.

John
];')

I don't have a dual battery setup in my KJ yet, wish i did, its on my wish list!! I did in the S10 i had, and that had a headache rack in the back with 400w on that alone, and another 200w on the front. I went pretty tame on the KJ due to its electrical system. I upgraded the alternator on the S10 to a 225 amp model and added a second battery, no problems!

The KJ is limited on the alternator because even if you put the larger 160a alternator in unless the PCM is reprogrammed it won't make a difference. The PCM controls the alternator. You can't take the larger Renegade alternator and toss it in a KJ and get more output, it will still be the stock output regardless.
 

kb0nly

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Finally added the breakers,updated pics in original post.
Feel better about the system knowing it's safe.

JL,does this qualify me for my Yellow Belt?

Looks damn good! Just finally got back to this post tonight. Nice looking breakers they will do the job.

You get pretty good run time on the second battery with the power inverter?
 

Kugellager

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The KJ is limited on the alternator because even if you put the larger 160a alternator in unless the PCM is reprogrammed it won't make a difference. The PCM controls the alternator. You can't take the larger Renegade alternator and toss it in a KJ and get more output, it will still be the stock output regardless.

I don't think that is the case. The KJ alternator only has two connections. One is the main output which goes directly to the battery and the other is a two-wire connector as in any standard 3-wire alternator that I believe goes to the ignition switch and indicator based on the wiring diagrams I have seen... and of course the case is grounded to the block.

Now after the battery everything is managed by the computer...

John
];')

P.S. Nice ham shack by the way!
 
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