* Truck Camper Renovation Update!*
– Click Below for a detailed layout of our full off-grid electrical setup, including harnessing Solar Power and wiring a Split-Charge System!
I spent the last two weeks after work wiring and making new updates for the truck camper. It may not seem like the most exciting projects, but it IS essential to maintaining an off-grid, self-sufficient setup. Tyema and I are trying to be as conscientious as possible; any way that we can cut down our footprint we will make the effort. A HUGE setback while having a little camper and being on the road is dead batteries. What’s worse than driving to some beautiful, remote mountain spot and realizing that your lights are dim and the furnace won’t fire up as soon as you get parked and ready to relax?!
While we idly wait for this work gig to end and as the winter slowly wanes I wanted to make sure that power would not be a concern when we hit the road at the end of April. We also want to avoid entirely camping in maintained, commercial campgrounds that charge for hookups, etc.. I bought (2) 100 Watt Grape Solar Panels from Home Depot and a PWM Charge Controller that can withstand a 500 watt load (40 Amps). This setup is incredibly easy to install, however with our particular design some factors needed to be considered. Our slide in truck camper is also a pop-up (the entire roof raises another two feet). It is not recommended or safe to add a lot of weight to the roof for the raising mechanism can be compromised. To evenly distribute the load I placed one 100 watt Grape Solar Panel on the front driver side and the other on the passenger rear side of the camper. These panels weigh roughly 20lbs each, with all hardware we have added 50lbs to the roof.
The Zippity Feet offered by Grape Solar at Home Depot is an extremely simple design that makes mounting the panels a breeze. One note of caution : this type of mounting hardware will not allow the panels to be raised or turned in any way to harness the maximum potential of solar in the winter months. For the other three seasons, the flat surface panels should draw enough power for our needs.
At absolute most it took about 3-4 hours to fully install the solar setup and have it correctly wired to our (2) 12V Interstate Deep Cycle Batteries. The positive and negative leads on the 10AWG MC4 cable were routed across and through the roof, behind the cabinets, refrigerator, under the stove and so on so that all wiring would be hidden. It is very important to protect the sensitive electrical components along the entire route. Adding fusible links along the positive lines will make sure that no feedback will destroy the solar panels or the PWM Solar Charge Controller. Since I wired the panels in Parallel ( click here to learn more about wiring either Parallel, in Series, or Series-Parallel ). I have effectively doubled the amperage output while maintaining the same voltage at 12V. Because of this I installed a 15 Amp fuse between the PWM Charge Controller and the two solar panels on the positive lead of the MC4 cable.
After the first fuse block was mounted and wired, I routed the Positive and Negative MC4 leads through the back of the refrigerator, under the stove and around the water heater to a dry, safe place for the Charge Controller. This was the easiest part to wire!
Next in line there needs to be a fuse between the Charge Controller and the (2) Leisure Batteries. I wired a 20 Amp In-Line Fuse to the positive MC4 lead then continued the run for both positive and negative leads to the battery.
I made sure to spread Dielectric Grease on the 3/8” threaded top post terminals to reduce any electrical static/shock as well as prevent corrosion on battery terminals. As soon as the contacts were made on the Batteries the Charge Controller illuminated, showing signals of battery health, solar amp draw, input, output and any accessory DC loads. The solar setup is done and ready to harness the sun!
When theory comes into practice we can understand that solar cannot be our only source of generating power for our (2) Leisure Batteries. There will be many cloudy days, rain or simply just setting up in a shady camping spot that will not allow sunlight in. We needed to think of a second alternative to make sure our batteries stay topped off. The solution? A Split-Charge System. It may seem a little complicated at first, and potentially risky tapping into the engine, but once you wrap your head around it, it is fairly simple. The idea of the Split-Charge System is to harness power from the engine’s alternator while the vehicle is running to send current to the Starting Battery as well as a Parallel Leisure Battery Bank.
For our situation is was easier to work backward, from the Leisure Batteries to the Starting Batteries. We ordered 15’ of 2 AWG Red Stranded Copper Wire and 15’ of 2 AWG Black Stranded Copper Wire. Just like in the solar setup we needed to install one fuse along the positive wire to reduce the risk shorting out our Leisure Batteries inside of the camper and another fuse inside the engine to nullify any damage to the VSR (explain below). These fuse blocks however require a much higher rated Amp Fuse to support the very high current that passes from Alternator to Batteries. I installed a 100 Amp ANL Fuse between Leisure Battery and VSR and another 100 Amp ANL Fuse between VSR and Starting Battery.
To safely run the wire I drilled a hole through the floor of the camper and the bed of the truck. After running both the positive and negative wires through the predrilled holes, I secured them to the frame of the truck as I led them into the engine with screwable rubber insulated clamps.
With the Positive and Negative 2 AWG wires routed inside the engine, it is time to wire the Positive end to the VSR. But what the hell is a VSR??…
A VSR is a Voltage Sensing Relay that allows current to be distributed on either end. In other words…. When a vehicle is running the alternator sends current to the Starting Battery so that it may charge, and in turn start your engine the next go around. But we want current to also pass THROUGH the Starting Battery to the Leisure Batteries so that they may charge as well while driving. This particular VSR is a 140 Amp Dual Battery “Smart” Battery Isolator. It can “sense” the current of all Batteries and allow current to pass through all of them in order to properly charge all batteries. It will NOT allow the engine Starting Battery to discharge. It also will not allow a single battery to overcharge.
This is very important because with just a simple VSR or other relay there is no way to switch back and forth between Starting or Leisure Battery unless one wires a manual switch. If you forget to flip that switch, chances are your alternator will be sending power to the Leisure Batteries and you will find out that the next time you try to start your engine your Starting Battery is drained…
After the VSR is installed the Positive Wire runs into another 100 Amp ANL Fuse before being routed and mounted to the Starting Battery Top Post.
The Negative Wire MUST be GROUNDED TOGETHER onto the frame of the vehicle (or other grounded metal component) with the Negative lead on the VSR and then routed to the Negative side of the Starting Battery.
The Split-Charge system is fully wired! Now we will be charging our entire battery bank while we drive, and also when we harness power from the Sun!
Want to complicate it some more? Well now I want to be able to use 110V power inside of the camper for charging devices, using a fan, AC, etc… So back to the battery bank inside of the camper. If you want to transfer power from 12V to 110V you will need to wire in an inverter. We have a Solar 2000 Watt Continuos Inverter with three 15 Amp grounded outlets. Wiring this to the Leisure Batteries requires yet ANOTHER fuse! Again, this is to protect the inverter from shorting out as a response to the battery bank.
I wired another ANL type Fuse from the Positive 2 AWG Wire to the Battery. This time however the fuse had to be MUCH larger and heavier duty since the inverter can draw a very large amount of power from the Batteries. A little research showed me that a 2000 Watt inverter with 2 or 4 AWG Wire I should install a 400 Amp Fuse ( click here to determine the proper fuse size for your inverter ). The Positive lead from the Fuse and the Negative lead from the Inverter continue on to the Leisure Battery top posts. The final step is to ground the Inverter to something metal inside of the camper, or if you wish the frame of the vehicle. Close at hand, I used 10 AWG and ran from the Inverter to the 30 Amp 12V converter box which is already grounded, and the housing is metal. Without that one ground, the entire 12V system would not function in the camper!
Since the Inverter is in a location that is not practical for application I decided to go one step further with this electrical setup.
I installed three new receptacles around the camper that all lead to the 2000 Watt Inverter. Hiding the wiring was the most challenging part of the entire setup. With such an incredibly small space, I wanted to make sure that it looked as clean as possible, with no wiring exposed. I traced the lines of all previous, existing wires and routed the new wiring alongside them. All the materials were left over from when Tyema and I built our cabin in Pagosa Springs. It took some rummaging around the tool shed to find everything that I needed, but alas, no money spent on this occasion to wire the 110V side.
I used a standard 12/2 Romex Wire ( 2 conductors, 1 ground) to wire each receptacle. I wired one receptacle per 15 Amp grounded outlet. *Hint For Receptacle Boxes * – If mounting new hardware where no stud can be found for receptacles use the blue plastic junction boxes with the screw in push tab that can securely fasten to 1/8″ – 1/2″ wallboard.
Now when we want to use any 110V appliances we can simply turn on the Inverter, plug the device into the desired receptacle and power away!
There was a Carbon Monoxide Alarm hardwired originally in the below image, but on average it draws 4.0 Amps Per Day! I will be replacing it with a AA battery operated Carbon Monoxide Alarm, so in its original place I wired a new receptacle.
At this point I am satisfied with our electrical off-grid system and think that it will suit our needs for hitting the road this upcoming April/May. By no means am I an electrical engineer but I do have a lot of experience in 12V and residential 110V power systems. There are absolutely some changes that will be made along the way, and I will be sure to update as the potential meets reality. Have any of you created your own electrical setup in a camper/RV/tiny home/etc? Let us know in the comments below your ideas, methods or alternatives that could create another unique off-grid system!
Have any questions about your particular setup and need some advice? Post your questions in the comments below and I will be sure to try my best to help!