Charging 12V deep cycle bat in truck

[eleblanc]

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

 

[tdesanto]

I'm not an EE, so take this with a huge grain of salt.

Trying to charge 2 deep cycle batteries with the factory 12 outlet probably isn't going to cut it. They probably used 14 or 16 gauge wire at most; it could even be smaller than that.

If you try it, definitely run a small inline fuse...say 5-10A or smaller?

What are you going to be running off the batteries? My worry would be if they get really low and then you try to charge them, that they may try to draw too much power through the factory wiring. That's why I think that the plug should have a fuse in it.

Regarding the trailer batteries and charging while driving: if you have a 7-pin connector with the power lead connected to the charging system of the tow vehicle (that's standard by the way) then the batteries will receive some charge. But it's not a whole lot. More of a trickle charge is how I understood it when I started looking into it.

Good luck. Glad to see another monty owner here.

 

[bc_fjc]

I posted a reply to you on another board but the above is vary correct... I just found the my bookmark to a webpage that explains everything better then I can.

http://www.batteryfaq.org/

 

[eleblanc]

I'm not an EE, so take this with a huge grain of salt.

Trying to charge 2 deep cycle batteries with the factory 12 outlet probably isn't going to cut it. They probably used 14 or 16 gauge wire at most; it could even be smaller than that.

If you try it, definitely run a small inline fuse...say 5-10A or smaller?

What are you going to be running off the batteries? My worry would be if they get really low and then you try to charge them, that they may try to draw too much power through the factory wiring. That's why I think that the plug should have a fuse in it.

Regarding the trailer batteries and charging while driving: if you have a 7-pin connector with the power lead connected to the charging system of the tow vehicle (that's standard by the way) then the batteries will receive some charge. But it's not a whole lot. More of a trickle charge is how I understood it when I started looking into it.

Good luck. Glad to see another monty owner here.

I will only run a fridge for two days before i can recharge.

I will check my local RV seller, they probably have somethinig to prevent large amp draw when charging.

 

[tdesanto]

May I recommend a Dual Battery Setup?

I think a dual batt setup is warranted and a better outlet for the fridge. I ran a dedicated 12v outlet with heavier guage wire than stock. I think I ran 10AWG directly (fused) from the main battery. I upgraded the main battery to the highest capacity Optima (group 31). The 2nd battery is simply a backup whenever the main is run down. It's connected to a dual battery management system.

 

[BiG BoB]

Just to add my 2c,

You need to run a heavy guage power wire to the back, I'd recomed popping the bonnet (hood?) and checking what guage of wire runs from your alternator to your battery. There's no need for anything heavier than this, any smaller and you can loose some efficiency.

I'm a bit confused as to the location of your batteries. If they are in the back of your vehicle, and will be drained from when the motor is off, I'd suggest getting a device to disconect your vehicle from these batteries. I'd recomend a Redarc.

If the batteries are in the trailer, and the trailer will be unhooked, there's no need for a charge controller. Set yourself up with an anderson plug on the rear of the vehicle, normal trailer light plugs aren't good enough to charge up batteries.

As always, use fuses. There needs to be a fuse at each battery, incase the wire between then shorts out.

Sean

 

[eleblanc]

Just to add my 2c,

You need to run a heavy guage power wire to the back, I'd recomed popping the bonnet (hood?) and checking what guage of wire runs from your alternator to your battery. There's no need for anything heavier than this, any smaller and you can loose some efficiency.

I'm a bit confused as to the location of your batteries. If they are in the back of your vehicle, and will be drained from when the motor is off, I'd suggest getting a device to disconect your vehicle from these batteries. I'd recomend a Redarc.

If the batteries are in the trailer, and the trailer will be unhooked, there's no need for a charge controller. Set yourself up with an anderson plug on the rear of the vehicle, normal trailer light plugs aren't good enough to charge up batteries.

As always, use fuses. There needs to be a fuse at each battery, incase the wire between then shorts out.

Sean

The 2x deep cycle will be in the back of my montero, for the tripp i'm doing next week. But after that i will be installing them in the trailer permanently.

I will be using the trailer with my montero (12v) and my BJ42 (24v)

but for right now i was needing a fix to charge the battery for next week. I will be running 10 ga wires from the batt of the monero to the rear. Obviously when the montero will be stopped i will disconnect the 2x deep cycle from the truck main battery. This is just temporarly.

I need to have a trailer spare bracket done so i can move the spare tire out of the trailer, giving me more space for a wood box for the deep cycle battery setup, then i will do things appropriatly.