Power to truck bed - criticize my plan


My must-do upgrade before Spring is to get power into the truck bed for charging a camping battery while driving to run a refrigerator and other miscellaneous things (but the fridge is the main thing). (Up until now we've just put the fridge in the back seat of the cab, but we'll have an additional passenger on our Spring trip (Canyonlands Maze - yay) so we need the rear seat space.

My requirements/desiderata are:
1. To have capacity for 50A continuous supply (famous last words, but I think this should be plenty with lots of headroom for future uses). Main purpose is for camping battery charging while driving (but could also use it for, e.g., compressor for airing up when the camping stuff is not installed).
2. To be able to manually disconnect the system
3. To be switched on and off with the ignition (I go back and forth on this, vs switches in the cab or letting a DC/DC charger control the connection, but for now this seems like a good option).

To provide this, I would implement via:

a) 6 gauge wire (10 feet might be enough, 15 would certainly be more than enough). (1) (A probably dumb question I have - should I bring the ground wire all the way back to the battery, or is connecting it to the frame or similar sufficient?)
b) Inline 60A circuit breaker near the battery, also gives me a manual disconnect. (2)
c) 60A relay and socket (3), switched with an add a fuse to a switched circuit in the engine bay (3)
d) Terminated in an Anderson powerpole adapter (SB50 with environmental cover)

For checkout I will use this system with my existing Goal Zero (400Wh) camping battery, i.e. just make a Powerpole to cigarette lighter pigtail (I now charge the battery in the truck using the trucks cigarette power point), but the next step in the project will be to build up a better (higher capacity) battery solution with a dcdc charger and MPPT input (I already have a portable solar panel).

Besides general comments about the suitability of the plan, any comments about good workmanship practices would be welcome. (Although at one time I had a decent theoretical knowledge of electronics, all my actual experience has been hobbyist level in a benign environment).


New member
I ran a pair of 4 gauge cables from the drivers side battery on my 2013 F350 Diesel to a relay controller by 1 of the upfitter switches to a Anderson power pole in the bed of my truck. The upfitter switch is powered only when the key is on and it gives me the ability to switch it off and on. I used a blue sea donut fuse as there is not much room under the hood to put a circuit breaker. I used the Anderson waterproof boots for the connectors to protect them. The most difficult part was finding a flat spot in the bed to mount the PP connector.


New member
I've done this twice now.

I've put in 12v cig plugs which work well for me for most devices. I always have had a canopy on, so I don't worry about weatherproofing.

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I ran an ARB 50 off a cigarette lighter in the bed for years, no issues. #12 wire fused straight off the battery. Only time the fridge ever shut itself down because of low battery was on a 101 degree day and the battery was 6 years old. I went into work in the morning. noticed the fridge was up to 45 degrees when I came out.

Not saying you shouldn't add all of the extra stuff if you are looking for more long term flexibility. But if it is just a one-trip fix. You should be all right going the easy way out.


Active member
I'm currently in a different situation, but with similar requirements (except for the 50a continuous load requirement - you sure you need that much?). I've done a a lot of boat wiring over the years and I've found that SIMPLE IS BETTER. I see some of the plans of people here on this forum and I think "oh my God - if something goes wrong and they have not kept meticulous notes about how everything is wired and have a laptop handy with WiFi and Bluetooth, and remember how they programmed everything, they'll be screwed if they have a problem!" (I've had this problem on my own boat after a season or two of not tinkering with the electronics and having to go back to my diagrams and notes to remember how I did things). Every device is a point of failure. Every connection is a point of failure. Every crimp every solder, etc...

You don't mention solar as a power source, so I assume this means that you move around a lot (as do I) and will rely on the alternator for charging, so you'll skip the additional complexity of solar charge controllers, etc. You can also skip complexity by going with an old-fashioned AGM deep cycle battery, which has a lower initial cost, but the long-term cost per usable amp-hour is actually a lot higher than a LiFePo battery. (But then you have to deal with a charge controller and BMS, etc to deal with that).

I'm trying to decide on which route to take:

1) Hard wire everything (like your plan)
2) Create a portable setup that can double as a house system or move vehicle-to-vehicle

If I go the hard-wired route, I will probably use one of these:

I have an older version in my boat and it has been 100% reliable for about 5 years in a harsh marine environment. These newer versions apparently include a switch for your dash where you can override the automatic operation and manually combine or separate the batteries.

Wiring everything up is a simple matter of just following the instructions that come with the unit. Hardest part will be finding a place to mount the ACR unit. ;-)

For determining wire gauges, use the AYBC "ampacity" charts:

Just remember to measure the ENTIRE run (both sides of the circuit). A common mistake people make is only measuring the run from source to the draw. The ground side needs to also be included.


Thanks everyone for the responses!

a) I'm spec'ing at 50A out of an abundance of caution, i.e. so I never have to rewire.
b) I actually do have a portable 100W solar panel so I'll probably add a low capacity solar charger as a second step
c) I ordered a 100Ah AGM battery. If/when it turns out to be insufficient I'll consider an upgrade.
d) I've been religiously following that Blue Seas wiring gauge diagram.

I have all my parts in (I went with a Renogy 40A DC/DC charger). I'll provide an update (e.g., parts) when I get it wired and it works. While I have a fairly good understanding of electrical fundamentals, what I don't have is a good understanding of good workmanship fundamentals (crimping vs soldering, good mounting practices, etc.). Does anyone have a good reference for this sort of stuff?


You really should look into the Renogy Dc to Dc battery charger. Run #2 or #4 wire to the bed of the truck, depending on length, into a Renogy 40amp Dc to DC Charger and Inyo your battery. Your battery will charge in no time with no risk of damaging your alternator or your battery. These DC to DC chargers used to be crazy expensive, but now they are under $170....


New member

here is the best and easiest write up to connect to your trucks power system:

I chose a longer start cable as they come in the tight thickness, proper isolated and thy are much cheaper than extra orders cable.
My setup is a bluesea solenoid on the right battery, fish the starter cable plus and negative along the frame into the bed, anderson plugs, in the bed a 12v 100aH deep cycle battery. now you have plenty power for fridge and everything ;)

I also tend to overdo things, but I learned the simplest setup here is the best.



Well-known member
While I have a fairly good understanding of electrical fundamentals, what I don't have is a good understanding of good workmanship fundamentals (crimping vs soldering, good mounting practices, etc.). Does anyone have a good reference for this sort of stuff?

Bayou Boy

Unless you are using an actual DC-DC charger bump your fusing to 100A. If you draw that battery down significantly you have a very good likelihood of blowing 60 amps during the onrush when you first start the truck. The Blue sea terminal fuse blocks with MRBF fuses are the way to go for this use but buy the fuses separately as you can source them significantly cheaper from other role vendors in lots of 5 or so.

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Well-known member
I went with a Renogy 40A DC/DC charger
Should be fine. Mount it as close as practical to the house battery, and be aware of the environmental restrictions in the manual (no moisture, no dust, no high heat, good ventilation).


Well-known member
......what I don't have is a good understanding of good workmanship fundamentals (crimping vs soldering, good mounting practices, etc.). Does anyone have a good reference for this sort of stuff?
Tinned wire and tinned lugs

Proper crimper with the correc dies.

Don't solder. The flux cannot be removed once wicked up into the wire and keeps attacking the copper.....connection heats up....solder melts....I use to solder and seen the results.

Been using this method and the heat shrink connectors for decades.

Crimping 8-1ga wire the heat shrink goes on after crimping.
IWISS Cable Lug Crimping Tool for Heavy Duty Wire Lugs,Battery Terminal,Copper Lugs AWG 8-1/0 https://www.amazon.com/dp/B017S9EINA/ref=cm_sw_r_cp_apa_i_7.emEbME1XFA9

Over 1ga use a hydraulic crimper.

Make sure the heat shrink is adhesive lined.

Wire tie mounts or Pclips within 4-6" of a terminal and 12-30" after that . To run wire I plan the routing, install the mounts, put tie wraps loosly in the mounts then run wire. Stopped using adhesive backed mounts.

To make things look neat use some extra wire and run the wire parallel/perpendicular (not diagonnally) with 45-90 degree bends.

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+1 for tinned wire, crimped connections, and adhesive heat shrink. These are generally found in marine parts stores. Generally I would follow marine wiring practices: https://www.westmarine.com/WestAdvisor/Marine-Wire-Terminal-Tech-Specs

I have successfully used liquid tight conduit and boxes to protect wire runs and connections in my boat and my truck. This is not an accepted practice so far as I know, but has worked quite well for me.

It sounds like you are a thorough and detail oriented person, and this will help you tremendously with truck wiring. 90% of a good wiring job is well thought out plumbing of wires. Don't be shy about ripping out hours of work if you realize at some point there is a better way to plumb something. It happens.


Thank you everyone for your detailed input! I have a couple more 101 type questions.

1. What material would you recommend I mount the engine bay components (relay, circuit breaker) on? I'm a woodworker but don't imagine plywood is a good choice. Metal or anything conductive seems like a bad idea. I could just grab a random piece of stiff household plastic, but I have no idea how melty it might be.
2. Anything to look out for in wire loom selection? I don't think it needs to be weatherproof.