Tapping 12V from the truck to charge Battle Borns

[ncitro]

howson I have to agree. I would say I rank it above the solar panels even. They are great when its sunny, but it is amazing to be able to recover so much charge off the truck while towing in bad weather.

[bertschb]

howson I have to agree. I would say I rank it above the solar panels even. They are great when its sunny, but it is amazing to be able to recover so much charge off the truck while towing in bad weather.

C'mon guys! Quit laying it on so thick! I need to focus on my solar project.

[ncitro]

C'mon guys! Quit laying it on so thick! I need to focus on my solar project.

lol to be fair we use a ton of power. My residential fridge draws a ton, and we both work still. We do a lot of overnight Cracker Barrel’s add Walmart’s on driving day’s and if it’s raining it makes the difference between two of those back to back and needing to find a campground every other night. And it seems like it’s always raining lol.

[wygieman]

I recently returned from 6 weeks camping and using the DC-DC charging system and like it very much. Just a couple of notes on how I did it a little differently for a 5er though substantively I followed Howards model. I connected to the driver side battery and ran the wires down the driver’s side of the truck to match the normal 5er power connections. I also used an upfitter switch to control the power to the connector using a 200 amp solenoid through a 60 amp Blue Sea breaker in the engine compartment. I covered the two 4 AWG wires with split loom separately and put heat shrink over the pair where they are exposed in the bed of the truck. I routed the cables into the truck bed through the drain between the bed and the tailgate to avoid putting any holes in the bed, at least while I try it out. I did not use a separate D+ connection as mentioned above and directly hooked the D+ signal to the input as it is already switched. Another slight difference is that the output of the Renogy is connected to the DC circuits after the battery shutoff switch so that it can power the RV even with the batteries shut off should that be necessary. Even with 4 AWG wires, there was almost a 10% voltage drop over the run. With the voltage of 14.46 volts at the battery, it was 13.22 volts at the Renogy. The Renogy input current was 52 amps while outputting 40 amps. I was surprised to use almost all of the 50 foot rolls of wire I had ordered. A couple of pictures attached. I noticed on the other forum they had implementations using a frame ground to reduce the mount of wire run. I preferred using a full run of both wires to avoid an electrical connection under the truck.

Just an update to my previous post. After reading about the experiences of the people in Texas during the prolonged power failure and cold, I decided that I wanted to boost the ability to charge my RV during what I might call unplanned boondocking like in Texas or after a hurricane where I live. I have a pair of Honda generators for when I plan to boondock but don’t want to carry them when I don’t plan extended stays without minimal hookups. Also, I don’t carry the amount of generator fuel it would take for long unplanned periods without replenishing. I decided to up my Renogy DC-DC charger to the 60 amp version to increase the charge rate from the truck. I changed the breaker to 100 amp model and replaced the Renogy with the 60 amp version. It does work even though the voltage drop is significant as expected. Voltage at the Renogy input is 12 volts which is well above its minimum (shutoff at 8 volts and restart at 10 volts). It does draw 83 amps to produce 60 amps at the right voltage but the truck alternators have plenty of amps available. My 200 amp/hr bank can now be recharged in 3 hours of idle or tow from a significant discharge. Since I have an additional fuel tank, I also have at least 75 usable gallons of diesel in the tank when filled. I also added a simple toggle switch on a wire from the D+ terminal to the low current terminal. When on, the charger is limited to 30 amps when I don’t need the additional charging capacity (most of the time). Fyi as there is little cost difference between the 40 amp and 60 amp solutions. As a result, I have a lightly used 40 amp Renogy DC-DC charger for sale cheap if anyone is interested.

[ncitro]

wygieman that’s great info. I also saw the price was similar but when reviewing the manual they did not have a recommendation for wire size for the length I would need so I chickened out and went with The 40A. I’m glad to know it works fine.

[wygieman]

wygieman that’s great info. I also saw the price was similar but when reviewing the manual they did not have a recommendation for wire size for the length I would need so I chickened out and went with The 40A. I’m glad to know it works fine.

Yes, the latest manual shows 4 awg up to 30 feet for the 60 amp input but has no specs for longer distances on any of the models. The product is built to compensate for voltage drop so minimizing it probably isn’t as important as it usually is I guess.

[ncitro]

Yes, the latest manual shows 4 awg up to 30 feet for the 60 amp input but has no specs for longer distances on any of the models. The product is built to compensate for voltage drop so minimizing it probably isn’t as important as it usually is I guess.

Yeah I agree 100%. When I bought mine the 60 amp has just come out and it only shows like 5 foot, for vans I guess. That’s great.

[John L]

For those of you ncitro and wygieman and any others who have a 5th wheel how did you run the wires from the pin box to the DCDC charger?

[wygieman]

For those of you ncitro and wygieman and any others who have a 5th wheel how did you run the wires from the pin box to the DCDC charger?

There is room to run the wires straight back into the forward compartment from the kingpin opening under (rather above) the outer skin that covers the front of the 5er from the cap to the forward compartment. There is insulation in there but if you look forward from the compartment, you will see there is plenty of space to go straight back to minimize the length of the wire. Fish something from the kingpin opening to the forward compartment and then pull the wires through.

[ncitro]

For those of you ncitro and wygieman and any others who have a 5th wheel how did you run the wires from the pin box to the DCDC charger?

I tried fishing and couldn’t get a path. My bed is oriented front to back, so I drilled a hole above the pinbox and went up into the under bed storage, back a ways, and then came down into the front compartment. Sealed the holes with silicone and it’s been fine.

[Bbytes]

Howard,

Not sure if you are running a monitoring camera off the back of the rig and if its powered through the marker lights. I'm thinking about powering the ignition input on the charger in this manner.

Jim

Howard/Jim

Saw where someone ran the ignition input D+ From the positive input side of the DC-DC charger. Do you see any reason this wouldn’t work? When you plug in the charging cable it provides 12volt… when you unplug no 12volt!

Thoughts?

[howson]

Howard/Jim

Saw where someone ran the ignition input D+ From the positive input side of the DC-DC charger. Do you see any reason this wouldn’t work? When you plug in the charging cable it provides 12volt… when you unplug no 12volt!

Thoughts?

It should work. Personally I like how the D+ is triggered from the light circuit so I can turn off if desired (stuck in traffic on a hot day, etc).

[ncitro]

Howard/Jim

Saw where someone ran the ignition input D+ From the positive input side of the DC-DC charger. Do you see any reason this wouldn’t work? When you plug in the charging cable it provides 12volt… when you unplug no 12volt!

Thoughts?

I Just did an install on my father in laws trailer, and he did not want it on the trailer lights, so we did this. Note that it does not work on the output of the DC to DC charger (even though that should be hot from the trailer batteries) but does work fine when connected to the input side (which is the truck power). You would want to fuse it between the D+ input and where you tap off the truck feed.

[Bbytes]

I Just did an install on my father in laws trailer, and he did not want it on the trailer lights, so we did this. Note that it does not work on the output of the DC to DC charger (even though that should be hot from the trailer batteries) but does work fine when connected to the input side (which is the truck power). You would want to fuse it between the D+ input and where you tap off the truck feed.

So what size fuse did you use on your father in laws trailer?

[ncitro]

So what size fuse did you use on your father in laws trailer?

Smallest I had was 5 amps, but a 1 amp would be fine. Its just a set of relay contacts, it cannot draw much.