dc to dc charger wireing

[Turd Furgeson]

i am gathering the stuff to do the dc to dc charger.
i can pass a fish tape from the battery compartment under the insulation up to the pin box just to the right of the under deck light.

how should i get these wires thru to the pin box or thru the fiberglass lid?
a am thinking a 1" hole and grommet just to the right of the light on the lid.

any idea's or help would be appreciated.
pix too if you have em.

[uhftx]

I guess I"m not following you. If you are talking about the truck to camper charging. It is already there while your truck is running. It will charge the 5er battery. But if just connected without the truck running, It will not charge.

[Turd Furgeson]

the 3021 has a residential fridge...it draw 11 amps...the 7 way plug from truck delivers 7 amps...after 5 hours on the road the batteries are at 11.7v and the inverter shuts down and the fridge and freezer warm up...also...if you overnight at a circle j or somewhere with no hook up you may or my not have enough power to run your slides out, or in the next morning...
there is a great writeup on the dc to dc charger on here by daryles...hoping to hear from him...
i need to run 2 4 gauge wires from charger in battery compartment up to the pin box so it can hook up to the trucks powerpole connecter..
i have the snake under the fiberglass pan but dont know how to terminate. thru a 1" hole and grommet in the pan or some other way.
looking for idea's before i commit to drillin

[Daryles]

Here's a link to my write up of my install.
https://www.montanaowners.com/forums...hlight=charger

I used Gorilla tape to close the opening around the pin box.

[Turd Furgeson]

thank you for the pix.
did you put the negative thru a fuse as well?
it looks like it may be going thru a blade fuse.

is that factory in your rig? i dont see it in mine.
but i will looky closer.
do you think the neg side should be fused in a 12v dc system?
i am getting mixed input

[Daryles]

No, only the positive wire is on a 90A circuit breaker in the truck near the battery.
The black block you see is the negative bus bar.
Above it is the on/off switch.
Below it is the Victron BMV-712 battery monitor.
Here's a better picture.
No, none of this is factory.
When I upgraded batteries to lithium, I put in +ve and -ve bus bars, 0 gauge cable, 3 way switch (off, battery 1, battery 2, both, i kept the originalFLA battery as a back up), Victron BMV-712 battery monitor, 400W solar panels, Victron 100-30 MPPT, 2000W inverter.

[Turd Furgeson]

got the dc charger mounted and a 70 amp fuse behind it before the battery.
found the light up on my shelf of sacred junk and installed it to.
Let there be light,,and it was indeed good!
Waiting on wire and powerpoles.


found a flush surface mount for the anderson powerpoles. if there is enough room in the box/fenderwell for it i will mount it in the box of the truck.
i am thinking a 10 ft "extension cord" for when truck is unmounted and parked beside rig.


this thinkin sure is fun! thank you daryles!

[Daryles]

The wiring in the truck bed is about 8'.
I have another coil of about 8' rolled up in the pinbox. This way I can park the truck on either side and still have enough cable to plug in.

Remember IF the truck is NOT hitched, you have to provide a ground between the truck and the rig.
They must be on the same ground plain for the 12vdc on switch to work.
I use jumper cables from the rig front leg to a bolt head on the truck frame.

Last March when dry camping on Ocracoke Island OBX NC Campground we had 3 days of rain. Solar panels did not work. I used the DC-DC charger twice a day for an hour to charge the batteries. Having a 60A output really charges lithium batteries fast. Our 4000W generator only puts out about 30A, but we seldom carry it. We rely on the solar and DC-DC charger as a back up.

[Turd Furgeson]

daryl
i got it working...thanks for the heads up on common ground if unhitched.
didnt have a greeen light until i hooked the cables between frames....


how do you get the ac's to work going down the road? do i need to bring it back to the inverter for power????



this thinking makes my head hurt!

[Daryles]

By code, you need to install a transfer switch between your shore power input and your inverter output to have power into your power distribution panel.
This will allow you to run whatever you want BUT you must manage your load manually. In other words you only turn on devices your inverter can handle. Also if you have a transfer switch providing power to your distribution panel, you must turn off your converter circuit breaker. If you don't you will have an unnecessary loop from your battery, through the INVERTER, through the power panel, through the CONVERTER and back to your batteries. A total waste of energy.
When we are running off the inverter, I turn off all circuit breakers for anything I don't want accidentally turned on like the electric water heater, the ACs, fireplace, microwave etc.
The AC is a power HOG!!!
You need a LOT of solar and a BIG battery bank to run it off grid. Here's pictures of a test I did.
The AC unit is the 13,000 BTU forward one with a SoftStartRV installed.
This test was done without the DC-DC charger running (batteries alone). The 60A DC-DC charger would definitely help with the load and slow the depletion of the batteries.
When we get home from this trip i will be adding another 400 maybe 800W of solar panels. We are planning to go southwest next winter and attend the Circling of the Montans at Quartzsite in January.