Charging 12V deep cycle bat in truck

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eleblanc

eleblanc

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I need to know if i can use the rear cig lighter plug in the rear of my montero to charge 2x deep cycle battery connected in parallel. Can i simply use a cig plug and hook the + and - to the battery and that will charge them, or i need a special device. I'm leaving this weekend so if i need something special i kinda need something i can find localy.

How does the battery are charged on a camping trailer? is it only charged with when you connect the trailer to 120V? or does the battery also gets charged when the tow truck is hook to the camping trailer?

I will be camping 2 days in a camp ground them driving a whole day to the next camp ground, stay there 2 days and again to a third location.

TY!

EL
 
If you are using a 7 pin connector on your trailor and the truck has one also and all the connections are made the 7 pin RV style plug is made to charge your trailor batteries while you are connected to the truck.
 
Niner said:
If you are using a 7 pin connector on your trailor and the truck has one also and all the connections are made the 7 pin RV style plug is made to charge your trailor batteries while you are connected to the truck.
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The two deep cycle batteries are in the back of my truck, not in the trailer. Right next to a cg lighter outlet.
 
eleblanc said:
I need to know if i can use the rear cig lighter plug in the rear of my montero to charge 2x deep cycle battery connected in parallel. Can i simply use a cig plug and hook the + and - to the battery and that will charge them, or i need a special device. I'm leaving this weekend so if i need something special i kinda need something i can find localy.
Click to expand...

Connect + to one battery + and - to other battery -. Should only draw enough amperage to top off the batteries. If they're deeply discharged, this may not be sufficient though. I hope the rear cigarette lighter is fused.

eleblanc said:
How does the battery are charged on a camping trailer? is it only charged with when you connect the trailer to 120V? or does the battery also gets charged when the tow truck is hook to the camping trailer?
Click to expand...

Some MFRs provide a seperate circuit that is 12V+ to the trailer harness with a tow package for this purpose. Otherwise, you'd have to do this yourself. I'd run a 10g wire directly from the battery + via a 30A fuse or circuit breaker.
 
Last edited:
hj60 said:
eleblanc said:
I need to know if i can use the rear cig lighter plug in the rear of my montero to charge 2x deep cycle battery connected in parallel. Can i simply use a cig plug and hook the + and - to the battery and that will charge them, or i need a special device. I'm leaving this weekend so if i need something special i kinda need something i can find localy.
Click to expand...

Connect + to one battery + and - to other battery -. Should only draw enough amperage to top off the batteries. If they're deeply discharged, this may not be sufficient though. I hope the rear cigarette lighter is fused.

eleblanc said:
How does the battery are charged on a camping trailer? is it only charged with when you connect the trailer to 120V? or does the battery also gets charged when the tow truck is hook to the camping trailer?
Click to expand...

Some MFRs provide a seperate circuit that is 12V+ to the trailer harness with a tow package for this purpose. Otherwise, you'd have to do this yourself. I'd run a 10g wire directly from the battery + via a 30A fuse or circuit breaker.
Click to expand...

So if i connect my cig plug in the rear of the truck directly to my battery, it should charges, unless they are deeply discharge, i may blow a fuse? because deeper they are discharge higher the amp will be when charging?
 
eleblanc said:
So if i connect my cig plug in the rear of the truck directly to my battery, it should charges, unless they are deeply discharge, i may blow a fuse? because deeper they are discharge higher the amp will be when charging?
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That's right.
 
Now i do have a 12V to 120V 300W inverter. Could i use that with a 2/4amp small charger? does 300W inverter enough to feed a 4 amp charger?
 
eleblanc said:
Now i do have a 12V to 120V 300W inverter. Could i use that with a 2/4amp small charger? does 300W inverter enough to feed a 4 amp charger?
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You will have more loss using an inverter and then converting it back to DC... The biggest thing to watch out for is overloading your eletrical system. If a cable used is too small for the amount of current passing through it will results in the wire overheating and causing a serious fire risk. Make sure it is fused with the proper size fuse for the wire.

The other thing you should know is that you will never be able to charge the battery fully using this method, but it will help extend there run time and for a 2 day trip should work fine

The loss intruduced by the small size of a normal 12volt outlet might not be delivering the 13.5 volts required to properly charge the battery and the more current you draw the less voltage you have avalible...

I'm in the process of adding 2 deep cycle batteries to my trailor and have run 8 gauge wire to the trailor plug in an attempt to minimize the loss but I still see a loss that might not let the batteries charge fully within my normal driving time. But by having 2 deep cycle batteries insted of one should more then cut the recharge time in half, hopefuly making the system work for me.
 
Deep cycle batteries for marine applications will not properly charge from a Land Cruiser alternator so if you are using marine application batts you will need to top them off every so often with a 15 amp or higher battery charger to keep them fresh. I don't know what type of batteries you are running, I just thought I would throw that out there.
 
eleblanc said:
Now i do have a 12V to 120V 300W inverter. Could i use that with a 2/4amp small charger? does 300W inverter enough to feed a 4 amp charger?
Click to expand...

300/120=2.5 Amps
 
If you use your alt you will be efectivley charging 3 batteries in parallel. The volt reg will sense the avg. voltage and charge accordingly. What you propose is slightly effective for maintaining a charge but not adequate to charge them properly.

I would purchase a charge controller and connect it direct to your alternator, fused for 40-50 amps and run a #8 wire to the battery location.
 
photogod said:
Deep cycle Marine batteries usually at lest 15 amps and usually more to get a full charge except for Gel Cells which will get full with 15 or a bit less. The LC alt doesn't put out 15 amps. Comes close but not quite.
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Thank you. I didn't know that. I was looking into buying one of these for my battery set up.

Battery Isolation

Probably won't get that exact one, but similar from a local source.
 
That looks good but you're gonna want to run #2 wire to match the size of the original battery cable. Look into making your own cable sets. It is very easy and will be better suited for your needs. Cable from West Marine or your local welding shop works great. JMHO.
 
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