Tiny cargo trailer to camper/sleeper conversion

[Pedernal]

PM inbound.

[91cavgt]

Man I love this weather we are having!!!

Got another update on this build. This update though includes a warning about wiring that comes with some 12 volt electrical devices. But first, let’s talk about the progress, then I’ll get to the warning.



Got most of the ceiling done. Why is it taking so long? Because I don’t have a table saw, and while I do have a circular saw, I am cutting all of these cedar planks with a hand saw. This is to cut down on the noise level so I don’t bother my fellow RV neighbors! Not only that, but if I try to put the screws in with a drill, it immediately snaps the head of the screws off. So a screw driver is being used to put them all in, but some heads are still snapping off.

Got 2 of the 1X2 strips in place on the side wall next to the door installed. These strips are what the wall boards will be attached to, and they space the wall boards out enough to allow 1/2” foam board insulation to be installed.


The battery is now moved into its final resting place, although it is not secured to the floor as of yet. It is positioned just slightly ahead of the axle since it weighs around 70-80 pounds. This helps to center the weight while still giving enough tongue weight for a stable and smooth towing experience. The water tank will be mounted on the other side in much the same way.


So the solar charge controller had to be reprogrammed. My original goal was to charge the battery to 14.9 volts, but recently the battery was only charging to 14.6 volts. Once it hit 14.6 volts, I heard an audible clicking. Upon further investigation I discovered that the BMS has a high voltage cut out at 14.6 volts. Crud!!! So the charge controller had to be reprogrammed to charge until 14.5 volts. It has been a year and a half since I bought the BMS so I have forgotten it’s specifications. My fault entirely.





Now on to the warning. I am seeing a disturbing trend when it comes to the wires included in some 12 volt electronic/electrical devices. Take the switch panel that I am going to be using for example. This switch panel will be used to turn the lights, exhaust fan, water pump, radio, and other items on and off. Straight out of the box it came in, all 5 switches along with the 12 volt power outlet, USB outlets, and the 12 volt display were all wired in parallel!! Not only that, there were fuses on the outputs of the switches, not on the main input!! To add to this problem, there was a 0.3 ohm resistance reading on ONLY the power wires from the input wire to the last output!! This resistance will decrease the voltage that your devices get, will cause heat, and can end up causing a fire!! If anyone ever buys anything like this, you really need to rewire it so that each switch is on its own fuse BEFORE the power even gets to the fuse!

The problem is also not just with the switch panel. I bought a 2,000 watt pure sine wave power inverter that included a pair of wires that look like they might be 4 gauge but more than likely are 6 gauge wires. This is not adequate for a 200 amp draw that this power inverter is more than capable of having. When this gets installed on my RV, it will be wired up with 1/0 wire which is considerably larger and more capable. Once again, by going with the wrong size wire, you are going to end up with wires that get hot, especially at the terminals. This in turn is going to cause resistance in the wire which will decrease the available voltage AND is a fire risk.




By the next video, I want to have the ceiling finished. Then I can move on to the walls which should go faster, and start mounting and wiring the electrical components.


[ame="https://m.youtube.com/watch?v=-lNGR2cr7rY"]https://m.youtube.com/watch?v=-lNGR2cr7rY[/ame]

[91cavgt]

The ceiling is done!!! Hurray!!!! That took WAY too long!


The reason why it was so time consuming was the process required to attach the cedar planks. After holding them in place on the ceiling, I had to drill 1/8” pilot holes. Then had to use a screwdriver to manually screw in each stainless steel screw. Originally I tried a drill to put the screws in, but even at very low speed the screws kept snapping in half. By hand I was able to get about half of the screws all the way in with no problems. The other half of the screws would snap off only the head of the screw after the screw was thoroughly in place but not fully tightened down yet.


With that being said, all of the cedar planks are securely fastened to the ceiling, and I’m happy with how it turned out. I got another couple of 1X2 boards up on the driver’s side wall along with another sheet of 1/2” foam board insulation.


My next focus will be on getting the electrical roughed in, and mounting the battery to the floor.


[ame="https://www.youtube.com/watch?v=FBX9lau0X9Q"]https://www.youtube.com/watch?v=FBX9lau0X9Q[/ame]

[91cavgt]

Now that the holidays are over, I can get back to work on the cargo trailer!


Got a lot of the electrical done, but not finished with the electrical yet. Got the fuse/power distribution panel mounted and wired up, the radio is wired up, the solar charge controller is wired up, and the switch panel is mostly wired up. Still need to finish wiring up the 30 amp battery charger, hook up the shunt, and mount everything to a small piece of plywood to hide all of the wiring and make it look a little nicer. Got the speakers all mounted and wired up as well.

I installed a fan in the top of the box where all of the electrical is mounted in order to ensure everything runs cool. Don’t want heat to just build up in there, especially in the summer time!!

A couple of months ago, I placed an order for 2 small 12 volt 15 watt heating pads. These I intend to install inside the battery to keep the battery above freezing since it is a lithium battery. Luckily, I tested these heating pads BEFORE installing them because they aren’t 15 watt. They are around 60 watts and get VERY hot within just a few seconds! So, in my parts box are some high wattage resistors from an old project. I’ll be wiring these resistors in series with the heating pads to increase their resistance which will decrease the power consumption. This will decrease how fast they heat up, and should also decrease their maximum temperature as well.


With the price of wood going back up again, I think I’ll be putting the wiring on hold and get back to insulating the walls and putting the cedar planks up to cover the insulation. The wiring can be completed at any time since I’ve already got everything I need to finish that aspect of the trailer. So before the wood planks get up to or above $5 each, I’m gonna go ahead and work on that. Hopefully the weather holds out so progress can be made in that area.


[ame="https://m.youtube.com/watch?v=pmh5tDkRFkI"]https://m.youtube.com/watch?v=pmh5tDkRFkI[/ame]

[91cavgt]

My wife mentioned about us going camping over spring break. That would be a great time to take this trailer out to give it a basic test to see how it does. So, I’m trying to get all of the insulation and wall boards up before spring break. It won’t be finished by then, but it will be done enough to test out the insulation and electrical system.

[91cavgt]

After just a couple of days of solid work, I managed to get more accomplished than what I thought was possible! Got the 1”X2” furring strips mounted to the side of the trailer with liquid nails and screws. Put 1/2” foam board insulation in between the strips, then used more cedar planks for the walls. Managed to get the front wall and right side wall pretty much done. So now, with the exception of the top corners and doors, the trailer is insulated.

Now my attention will go back to finishing the electrical. The Dewalt power inverter is also going to have to be replaced as out of the blue, it stopped working. No big deal though as I’ve got a 2,000 watt pure sine wave power inverter ready to go in its place!!

[ame="https://m.youtube.com/watch?v=susDQgu678g"]Project Cargo Camping Trailer part 9 - YouTube[/ame]

[Texas Grown]

[91cavgt]

Electrical is done, mostly!!!

https://youtu.be/4ZH8KGuvMNA

[91cavgt]

Now the electrical is 100% done! I was a nervous wreck cutting the huge hole in the side of the trailer for the electrical power cord. But now that it’s done, I like the position, just wish it blended in better. Got a surge protector mounted inside the trailer. The other side of the surge protector goes to the plastic cover on the outside that I just installed. Inside that cover is also a power cord that runs to the power inverter. With the two cords plugged in to each other, it gives easy access to plug electrical devices in while running off of the power inverter. Obviously the battery charger would be unplugged when ran in this mode. But when at some place that has electricity, the two cords can be unplugged from each other, an extension cord will be plugged in to the surge protector at the trailer, and the other end would then be plugged in to an electrical outlet. This would then provide 120 volts to run the battery charger and to run anything else.

The intake and exhaust fans are also now fully installed and working with the exception of trimming a little more plastic off of a vent to make them run a little quieter. The top vent inside the cargo trailer is for the exhaust fan. This fan is a 12 volt squirrel cage fan that blows into 3/4” PVC pipe which is then routed to the water spigot inlet on the drivers side of the trailer. It flows a lot more air than what I thought it would. The intake air comes from a 1 1/2” hole in the floor, through a 1 1/2” PVC pipe, and then into the cabinet where the 12 volt computer fan is. Covering the hole in the floor is a perforated metal cover to prevent insects and rodents from getting into the trailer.

It is coming along and is finally starting to look how I wanted it to look. Now to start on the flooring………


[ame="https://m.youtube.com/watch?v=8pf8Hg7Pxeg"]Cargo Camping Trailer part 11 - YouTube[/ame]

[91cavgt]

It’s been a hot minute, but now I have time to get back to work on the trailer since the honey do list is all caught up on and school has started back up. In the months since the last update, this trailer has been put to work. It has transported fragile collectibles that came from East Germany, moved a whole dining room in one trip, and even transported a piano. It rides surprisingly smooth even when it is empty.


So the first job to tackle is the floor. Since the walls and ceiling only have minimal insulation in them, and because of the low ceiling height, I didn’t want to add any foam board insulation in the floor. But it would be nice if the flooring did provide a small barrier to help when it is cold outside. So the decision was made to use cushioned work mats. After trimming them to size, I think it turned out pretty decent. It is also a LOT easier on the knees when kneeling down inside. My only concern is how it will hold up to use, but only time will tell.


Next up is to mount the water tank, mount and plumb the water pump, and start running the water line to where the kitchen is going to be.


Edit: sorry about the upside down picture, and the sideways picture. I have no idea why it did that.

[bfree]

Looking good......

[91cavgt]

Got some more work done.


There is going to be a water tank in here, but the tank is HUGE! 40 gallons! Why so big? Because I already had it from a project a while back. This water tank is going under the bed/couch so it will be out of the way. But I am also making it easy to remove so the trailer can still be used to move things.

So the water pump is permanently mounted on the side next to the back doors. The inlet has a quick disconnect fitting so it will be easy to disconnect the tank for removal. I’m just hoping that the quick disconnect fitting that I am using won’t leak since the fitting is designed to be under pressure. The water pump itself is rated at 3.0 gallons per minute at 45 psi of pressure. This should be more than enough for just a sink. On the outlet side of the water pump, a 1/4” ID hose is ran behind the trim that goes around the back doors. Eventually, the trim on one side will be expanded to also cover the water pump. Hopefully this will help to decrease the sound of the pump running.

So before I get to work on the couch/bed, I need to finish the trim work around the pump.