Renogy DC-DC Charger Installation

Mouseketab

We installed this mostly in the truck, and only added some wire to the trailer. But here is our DC-DC Charger install. A PDF file with full description attached. UPDATED - DO NOT disconnect the ground wire from the 7-pin wiring, merely add the new neutral to your ground bundle or ground pin in your junction box. UPDATED PDF file.

DenisP

Very nice installation. We installed a Victron DC-DC battery charger earlier this year and have been very happy with it. 

JeffroNC

Thanks for taking the time to post this. Do you have any test results? 

CrabTab

Beautiful install @Mouseketab!  Thanks for providing such clear, downloadable documentation too.

Mouseketab

JeffroNC said:

Thanks for taking the time to post this. Do you have any test results? 

Not really yet. Haven't gone out. We did hitch up the T@B, and when we crank the engine, the digital meter does jump up when hooked up, so it works, but haven't gone driving when pulling the T@B yet.

JeffroNC

@Mouseketab OK thanks, its got to be better than the 4 amps or less I get from the factory setup in my F150. :-)

Blueespy

What timing.  I have a F-150 (2020) and it def doesn't charge my new lithium batteries while moving.  My brother-in-law a diehard Air Stream guy is going to do something similar on his rig and suggested I consider the same for our t@b.  I like the fact everything is in your truck.  I am though confused a bit on the trailer setup.  Could you send some more pictures or explain it a bit more?  Our t@b 400 BDL is a early 2019 model.

Mouseketab

What I did was open up the junction box under the front of the T@B and disconnect the hot that runs through the 7-way line on the trailer. Then I ran new wire in a wire chase along the 7-way cord and zip tied it to the 7-way cord with the other end of the Anderson connections toward the truck, then tied in the new wires to where the old hot and ground were in the junction box. I sealed off the old hot that was in the 7-way cord with heat shrink tubing. On a 2019 400, you will probably have a junction box with lots of posts and the wires put on the posts with ring terminals.

Anderson connectors on truck end.



New wires zip tied to 7-way cord.

Junction box on 400

7-way wiring. So disconnect the black coming from your 7-way inside the junction box, and feed in the new wires and hook them in the same spot. I used red and black wire, and made the red hot, and the black ground.

cafyrman

Anyone know what size the junction box to battery feed is on a 2018 400?  I'm looking to do the same and was thinking about this exact same procedure, but I'm worried that the battery feed is too small a gauge for the DC>DC converter I bought -- a Victron 18 amp.

Dutch061

I am not sure of the wire size, I suspect 8 Gauge which is more than adequate for 15 Amps. 8 Gauge would pass 15 Amps up to 28 foot.

Looking at the photo of the junction block above, I think this is a safe assumption. 

Brad

ScottG

FYI, that photo is of my junction box, on a 2015 320. The battery wiring is all 10G. I suspect the 400 is configured the same, but I don't know if the battery wiring is any heavier. 

Mouseketab

ScottG said:

FYI, that photo is of my junction box, on a 2015 320. The battery wiring is all 10G. I suspect the 400 is configured the same, but I don't know if the battery wiring is any heavier. 

My apologies Scott. The thread was about a 400, and I misread. I was mainly trying to point out that the junction box is completely different than mine, which is some wires in a box tied together with wire nuts.

Blueespy

Mouseketab - thank you for the additional photos.  I too had a question regarding the gauge of wire from the junction box to the batteries.  My Air-Stream loving brother-in-law was at a recent Air Stream rally and attended a seminar on DC-DC Charger Installation.  I sent him your posts and his two comments were - yep this will work as long as he uses the same gauge wire and "in the seminar it was mentioned the Charger should be as close to the batteries as possible", which isn't an issue in an Air Stream but could prove challenging in a t@b 400, but it looks like this gentleman came up with a clean solution.  I'm going to start complying my supply list and hope to have everything when my son (a certified electrician and a very good mechanic) visits.  I'll be incline to let him read your post and then grab a chair, find a shade tree and enjoy a cool one while my young son breaks a sweat.  He'll love the challenge and appreciate his Dad's shade tree comments. 

Mouseketab

UPDATE - Only remove the HOT wire from the 7-pin wiring, and replace it with the HOT wire from the Anderson connector. DO NOT remove the ground wire from the 7-pin wiring, just add the additional neutral from the Anderson connector. (Your lights won't work)

Dutch061

Brakes won't work either unless there is enough of a ground connection through the trailer ball. Which I wouldn't want to depend on either.

Brad

Mouseketab

Dutch061 said:

Brakes won't work either unless there is enough of a ground connection through the trailer ball. Which I wouldn't want to depend on either.

Brad

I have surge brakes, so don't have that consideration, but you are right

Blueespy

Mouseketab, have you had the opportunity to do a test run with your DC to DC install?  I am planning to make the gear purchase and do the same install mid-Nov but wanted to ask if everything seems to be working as you planned. 

Mouseketab

Yes I did. I took the T@B to Georgia, and ran the 12V fridge while driving (6 hours), and the T@B was still fully charged when I arrived at our campground. No detailed testing, but the plug in meter showed 12.8 just before connecting to the truck, and then showed 12.8 when we arrived and disconnected before plugging into the campground pedestal. Same thing for the trip home.

Tundra57

I installed one in the front gas box of my 2019 Tab 400 a couple years ago. Uses the usual charging wire from trailer plug to enable. Power comes direct from battery using dc battery plugs like in pictures of other installation here. Battery goes through winch solenoid and ignition fed switch on instrument panel in truck so I can disable it. Mine works great too. 20 Amp version.