Builds Joltman's Build: The Overkill Weekender (1 Viewer)

[joltman]

I am a poor sleeper. I have a CPAP and it has helped me a lot. I was worried about not having it on our camping trip. If I don't use it for one night, I'm irritable the next day. I don't want to think about what I'd be like after two nights. How can I solve this? Well, one way is to borrow/purchase a portable power station with AC inverter. But those are a lot of money after I've already sunk a bunch into the house battery for the truck. Plus, I don't want to owe anyone a favor for letting me borrow theirs! But how can I power my CPAP from the house battery? One option is to get an AC inverter. However, I didn't want to go this route as they can waste lots of power and with 100Ah (~1280Wh) in the house battery, I needed all I could spare. The other option is to power the CPAP from DC power directly. The CPAP requires 24V at 3.3A (79.2W, and over 8 hours of sleep that equals 633.6Wh full blast, at 80% usage, 506.8Wh). This option makes more sense as I will have very little conversion loss. So, I decided to build my own portable power box that would plug into the house power system via a long cable. The cable would run from the house fuse block, through the closed rear door, 30ish feet into the tent.

Harbor Freight trip! There are some power hurdles to get through. The longer a cable is, the greater the voltage drop will be on that cable. Having a thick gauge wire is important. I went with 10 gauge. The other way to combat voltage drop across a cable is to utilize a higher voltage. I purchased a 12v to 24V boost converter and put PowerPole connectors on it. That plugs into the fuse block, and the 30' cable has PowerPoles on it as well. The box has the matching PowerPoles and a power switch rated for the amperage it could see.

Inside the box you will see that the 24V lines goes directly to a fuse box. There is a single 7.5A fuse that goes out to the 7.4mm DC barrel jacks. These are for the CPAP. As I said, the CPAP requires 24V @ 3.3A. I added two barrel jacks in case the wife ever needed to power a CPAP too. There's another fuse that goes to a DC buck converter. This buck converter takes the 24V and drops it down to 12V. I did this so I could power two USB C chargers. This way, the wife and I could charge our phones in the tent as well.

This solution worked great! Except for one thing... My CPAP utilizes a heated tube to keep the air humid and not condense back into water. If the water condenses in the tube, it can cause a very loud, sleep interupting gurgling sound. The standard CPAP power adapter looks like a normal DC adapter, but it actually has three wires. Standard DC + and -, but also a "sense" wire. That sense wire is what allows the unit to operate the heated tubing. Check out this video for more info. Long story short, I didn't have time to get the sense wire configured. So
my CPAP worked, but the heated tube did not and caused some issues in the middle of the night. At least I was more rested than not having the CPAP at all.

The battery was at 99% charge when we went to bed. In the morning, after charging our phones and running my CPAP, the battery dropped to 55%. That's quite a lot, and if I were to use my heated tubing, it would be even greater. If my wife brought her CPAP on a future trip, we would be really low on battery power. How would we survive a second night??

 

[joltman]

The answer:

I installed a Victron MPPT Solar Charge Controller. It connects directly to the Lynx Distributor and has configuration profiles for a LiFePO4 battery. This is another device I had planned for back in 2022 when I built the power board. There is an aluminum sheet behind the Orion DC-DC charger so that the aluminum cooling fins wouldn't be in contact with flammable wood. I made the aluminum sheet long enough to accomodate this specific SCC. I guess planning pays off! The right most terminals are where you connect a solar panel. I used 10 gauge wire and an Anderson Power Plug SB50 to create a pigtail. Then I made a new 30' 10 gauge cable (from stiff solar wire) to run from the pig tail, out the closed passenger door, to the solar panels. I wanted to get a 400W solar panel, but no matter which way I measured, there was no way to fit it inside the vehicle for the trip out/back. And the roof rack was packed to the brim, so it couldn't go up there. I ended up going with a Renogy 220W solar suitcase. This thing is great! In direct sun, I have seen over 184W of power. That can charge the battery up pretty fast.

So that was the plan. Use a solar panel to charge the house battery up after a night of use. It was a foolproof power plan. What I didn't anticipate is the extreme cold at the camp site. We got there, started to unpack and it started raining. Not just a little rain, but a huge downpour. I had to set our tent up in the rain. And it got cold. Much colder than I thought it would with three of us in a tent. My wife and I had trouble sleeping we were so cold! We got up the next morning to sunshine and clear skies. I got out the panel and it started charging the battery. Because we were so cold, we knew we couldn't do another night, so we packed up and went home...

New, 0°F sleeping bags and quilt will be delivered this weekend.

 

[joltman]

We made the best out of the next morning. We saw a few people come up the trail that morning. We wanted to get out and explore a bit before leaving. It was great getting out of the daily grind.

I learned a lot on that trip. Like, when you setup your tent in the rain, don't forget to put on the rain fly. And don't forget to change out of your open toed sandals during the ice cold rain storm. The trip also taught me a bit more. The cooler was too small. Food, ice, and drinks take up a lot of space, even for 2 days. Obviously, we did a bad job at food packing, but I don't like soggy lunch meat and cheese. I really wanted to get rid of the cooler...

Oh my...

Straight from South Africa via Salt Lake City and Equipt Outfitters. This is the 75L dual zone smart fridge/freezer from National Luna. I'd been eyeing this fridge for years ever since I saw an NL frige in the @indycole build. This thing is VERY heavy. Its just awkward to move around by yourself. I had to get it on the slide by myself too. With a lifted truck, that was fun, and I'm 6'3"! But no dings or scratches on the fridge or truck getting it onto the slide.

LIKE A GLOVE!

This was a tight fit, but it really fit amazingly well. You can see that I tried to use the Trekboxx straps, but I didn't have rubber feet on the fridge, so it was sliding around really badly. I had to take it back out because I didn't want to dent or scratch it.

 

[joltman]

To solve the sliding issue, I ended up purchasing the fridge baseplate from Equipt and spending more money on shipping. Oh well, that's how it goes. I also got the red removeable hinges for the doors and an extra power cord with only the proprietary NL power plug end. I spent a very long time making sure the fridge and plate where completely square in the cage. Marking the slide, double checking square and fitment several times before I drilled the first hole. I'm absolutely amazed at how perfectly the fridge fits. Seriously, there was a millimeter of clearance on either side, but it cleared and didn't appear to be rubbing at all. LATCH side:

HINGE SIDE:

Because of the weight of the fridge, and the seriously sturdy baseplate, I didn't get any good photos of the install of the baseplate. This is the best picture I have that shows the baseplate installed:

I used stainless steel metric hex screws, washers, lock washers, and nylock nuts to fasten the plate down to the slide. Very tight fit with the food prep table underneath the fridge slide, but it all fits wonderfully.

The power was something I wasn't sure how to solve. I know that TB offers a bungy cord to hold the cable up. I was afraid that due to the tight fit it might not work well. I had been eyeing the ARB cable guide. I called Slee and they had 2 in stock. I drove up and bought one. I went to my truck and pulled out the slide and cable guide. It wasn't long enough to attach to the slide and the front of the drawers. So I walked back in and bought a second one. The cable guide is just links in a chain. You can add more links if you have more chain. I got home and looked at the second chain. Guess what? IT'S A DIFFERENT CHAIN THAN THE FIRST! What fun! I was able to get them to join together, but the connection point was not stable. I attached the chain to the slide and front of the drawers with screws that came with the kit. After several uses, the chain broke. Once at the point where the two different links met, and another next to the staionary mounting on the front of the drawers. I don't have any photos of that.

The first chain I bought seemed to be made of better quality nylon than the second chain. It also had embossed lettering on the links that showed the model. Guess what? You can get it on Amazon for cheaper (10x11mm, comes with screws, but without the ARB custom metal mounts, which I don't use anyway). Oh, and you get 2 of them! So I guess the ARB cable run is not the best use of money, let alone buying two of them.

So everything is perfect, right? Not really. Over time, there's been more squeaking and rattling going on in the back. I've eventually discovered that this is due to the TB cage screws loosening up with vibrations. That's not TBs fault at all, that's just how things go. The scews require occasional tightening (like after a large trip where we pack the back to the brim with stuff). That's to be expected. But even after that tightening, I still hear squeaks. Actually, two types of squeaks. I eventually tracked it down to the red hinges being so close to the wire of the cage that its rubbing. So I took a chisel and shaved off the "drip edge" of the hinges. That immediately solved one of the squeaks. The second squeak is coming from the chain! It's not rubbing on anything. Its just such a long elevated chain that the links are moving every so slightly and it's causing squeaking. For the moment, I have a small piece of foam holding up the top chain. But I need to get out there with some velcro to hold the chain against the cage. It would help to show you in pictures but I don't have them at the moment. I'll take some and edit this post with those photos.

But with those squeaks taken care of, the interior is silent once again. I'm just amazed by this truck. This build has been so much fun, and taking the family out into the wilderness has been a joy. I really hope our kiddo has some fun memories of us camping. And we're going to continue it this summer. I'll sit you down for a slideshow when we get back!

 

[joltman]

There's always another truck project. Here's a sneak peak.

I just need to get off my lazy bum and actually do it...