DC - DC Charger Project

[Yoda]

Yoda Keith, I was looking for a 2 pole twist lock like we use at work when the class 8 power wires for trailers crossed my mind. Someone probably makes a smaller amperage one that may be cheaper, but those are pretty easy to get at a farm and ranch store or truck stop should something happen.

Found these on ZORO Says US made??? 1/2 Pollak price
https://www.zoro.com/grote-trailer-p...59/?q=82-1042v
https://www.zoro.com/grote-trailer-s...029/?q=82-1041

Horizontal pin similar to Pollak
https://www.zoro.com/grote-socket-2-...41/i/G5965878/
https://www.zoro.com/grote-plug-wspr...887/?q=82-1042

Not sure which is better

[acoleman43]

It should be 397 amp if the order guide is correct. Comes with the in cab instant heat option on the diesel.

With the 397 amp alternator, you should be able to choose whatever charger you want

I like Victron so my vote is for the Victron 12/12-30

[Jlawles2]

Yoda Keith, I was looking for a 2 pole twist lock like we use at work when the class 8 power wires for trailers crossed my mind. Someone probably makes a smaller amperage one that may be cheaper, but those are pretty easy to get at a farm and ranch store or truck stop should something happen.

[Yoda]

Yoda How many amps do you have available from the alternator of you tow vehicle?

It should be 397 amp if the order guide is correct. Comes with the in cab instant heat option on the diesel.

[Yoda]

Yoda Keith, I would measure from one battery to the 7 way RV trailer plug by using a fiberglass tape and following the same route that you will put the wire. From there use the RV side of the 7 way plug as a reference for the 12 VDC interconnect cable up to where the DC-DC unit will be mounted. Add these 2 numbers together. It may not be the right thought, but if the 7 way has not been too short for any situation you have been in, the 12VDC interconnect cable should be safe also at the same length.

I'd consider one of these for the interconnect cable end:https://www.amazon.com/POLLAK-2-Pole.../dp/B078WD7792 and the mating vehicle side https://www.amazon.com/POLLAK-2-Pole...78WD8X3K&psc=1

Now that would make the in bed connection a snap - Thanks. I guess I could use 4/2 or 6/2 SOOW cable to the trailer too. Thanks for the wiring length tip - I'm guessing it is now about 30' give or take (so 4/0 range). I'll measure my old truck to see. By the time I run two welding cables plus loom I am near the SOOW cable price too.

Thanks Joseph
Keith

[Jimmer]

For reference, I went with a Renogy 60amp DC/DC charger. I'm using 2 gauge wire wire and a Mechman 320 amp aftermarket alternator. I'm pulling 86 amps out of the truck to get 60 amps out of the Renogy. Of course, I can switch the charging from 60amps to 30 amps. I'm using the Keyline Iso-Pro 140 battery isolator which is connected to ground through a switch on the dash in my truck. I don't have any solar (yet) so I wanted maximum charging of the 5 Battleborn 100ahour batteries in my RV. I'm very happy with this setup.

[acoleman43]

Yoda How many amps do you have available from the alternator of you tow vehicle?

[Jlawles2]

Yoda Keith, I would measure from one battery to the 7 way RV trailer plug by using a fiberglass tape and following the same route that you will put the wire. From there use the RV side of the 7 way plug as a reference for the 12 VDC interconnect cable up to where the DC-DC unit will be mounted. Add these 2 numbers together. It may not be the right thought, but if the 7 way has not been too short for any situation you have been in, the 12VDC interconnect cable should be safe also at the same length.

I'd consider one of these for the interconnect cable end:https://www.amazon.com/POLLAK-2-Pole.../dp/B078WD7792 and the mating vehicle side https://www.amazon.com/POLLAK-2-Pole...78WD8X3K&psc=1

[Country Campers]

Yoda

This is good timing as I have been pondering a similar setup for my new battery system. I believe that Guest Jim has installed and is using a Renogy 20 amp for his single battery setup with the stock wiring on his truck with no issues. I will be following closely to see if I will go with your setup or choose another way, it is nice to have a large test base with this Forum.

Brian

[Yoda]

Well after reading howson Howard's tutorial - https://gdrvowners.com/forum/operati...e-battle-borns and many others I have decided this will be a good project for my new truck and plan on what I need to complete the project, This time getting only what I need. Thanks to everyone for the parts list and links.

First DC-DC charger selection.

How big do I REALLY need? I want to charge batterys and run fridge using my Multiplus. I usually drive 6 to 10 hours a day. So far solar has kept everything up, but I am not trying to run the fridge yet Fridge is Dometic single door DM2862RBFX https://www.dometic.com/en-ca/outdoo...-2882-_-183126

Input voltage (AC) 120 V
Input voltage (DC) 12 V
Rated input current (AC) 2.7 A
Rated input power (AC) 440 W
Input frequency 60 Hz

From rough numbers the 30A charger should handle it. Assuming 120V. at 2.7A is 27A at 12V or 24A at 13.4V I need to run a teas with the multi plus, but couldn't today as I have hard switch set to charger only (did not have cargo key with me) and touch 50 would not turn the inverter on for some reason. Amway once I get it to fire up I was going to see the change in power usage for inverter on with fridge off, then with fridge on. Is my math correct? Remember I have solar on top of this.

BTW - I noticed only one solar panel was providing any input (batterys at 100% ) Both MPPT's are set to the same profile - bigger unit is controlling - both on per Multiplus. I guess I should take some screen shots.

Renogy has 3 units out there 20A, 40A, and 60A - well documented in Howard's write up. Can be set for various battery types, but not fully programmable
https://www.renogy.com/battery-charg...rt=bestselling

Victron Energy has 12/12-18 and a 12/12-30 Bluetooth and Victron connect compatible and charge profile is customizable - about twice the cost of the Renogy.

So first question is what do I need and which unit should I get?

Second is wire sizing. If i go withe Victron 30A unit
it appear I can go with 6AWG wire. F350 CC long bed with 5th wheel should be about 25' -30' battery to battery. Am I correct on this or just plan o 4 awg as others have used? I know I would need 4awg for the 40A or 60A Renogy.

Thanks for getting me off on the correct foot
Keith