Another set of blinds

When sleeping in the car I had to take measures for covering the windows. The rear window has a roller blind, and the driver-side rear window (over the kitchen) has silver horizontal blinds. The windows at the rear seats I covered with two hanging-down organisors, one at each side, which also provide space for putting some odds and ends there. The front window was covered by a black blanket. Only the very rear passenger-side window did not have any cover.

I fixed that now: another set of horizontal silver blinds.

First-time sleeping in the camper

I decided to give it a try and spend one night in the car. I put up the bed on the passenger side, because this allowed me to keep the microwave in place.

Quite a cozy narrow room. Probably similar to being in a space craft! The TV works fine, I always had a cold drink available, and the electric heater worked well in this English cool summer night, powered by the external 240V power.

And more finishing touches at the electrics

In principle all the wiring had been completed, but two things needed to be done: the internal lighting of the switch for the external 12V supply needed to be connected, and the ampmeter for the internal consumers needed to be properly wired so that it also would show current when the power supply was used instead of the solar/leisure battery circuits.

The switch does connect the POWER-ON line with the GROUND from the power supply. I decided to use the -12V as the other connector for the switch illumination, so that the direction of the current is the same as originally intended in this switch (there is ACC, power, and ground connection at the switch, and since ACC and power are already on ground level, the remaining connection should not be +12V; this is important if the illuminator is an LED, where the direction of the current matters).

The ampmeter just needed some rewiring of the common ground return cable, which I had connected to the common terminal block instead of going through the ampmeter resistor first. I changed this, and now the meter also shows the current when the consumers in the car are connected to the 12V power supply instead of the leisure battery.

The cabling looks chaotic, but is all well-thought-through :) :

Once the cabling is hidden and the big wiring board is moved and affixed into its position, it looks more tidy. Even the coffee machine is back in place:

Another Microwave Cooking: Bacon

In the microwave oven I had boiled half a liter of water, had cooked five eggs, and now another challenge would come: I would use the other side of the microwave dish to cook some bacon.

Here is one slice of bacon before cooking:

After 20 seconds:

After 40 seconds:

After 60 seconds:

After 80 seconds:

After 2 minutes:

Tastes delicious!

Finalising the Electrics

Two items still were not yet installed: the 12V power supply from an external 240V mains power, and the recharging of the leisure battery from external 240V mains. I had already made the plans and wire diagrams, I only needed to make the actual connections.

For the battery charger I used one simple toggle switch to trigger two relays which would reroute the connection of the leisure battery: in normal condition the battery would be connected to the whole electric / solar controller setup; when activated, the relays would interrupt this connection (both the +12V and the ground) and would connect it to the output of a 12V car battery charger, which is connected to the 240V mains. A green LED indicates that the battery is being charged.

For getting 12V power while the leisure battery is being charged, it is advised not to draw current while the battery is being charged. The charger only provides up to 4A in slow-charging mode, and it would be overwhelmed to also drive all the consumers, if the battery is already quite flat. Therefore, the power for all these 12V consumers must come from another source: a 240V-to-12V converter was needed. When I checked online, I noticed that transformators and adaptors were either very expensive or did not provide sufficient power. I wanted to be able to have 30A at 12V, which is 360W. The solution seem to be switchable power supplies. And fortunately there is a good source for low-cost high-power 12V supplies available: PC power supplies. They provide high power, stabilised. I got an 800W power supply, which then theoretically could provide 66A. There are many web sites which show how to connect the wires. Important is that a power-on lead needs to be connected by a switch to Ground - this then powers up the power supply. All yellow cables need to be connected for the +12V line, all black cables together form the Ground. There are also +5V lines (all red cables) which I am not using now; and there is also +3.3V. But I only used the +12V and teh Ground. The Ground is steadily connected to the consumer circuits' ground, and the +12V is switched by a relay which connects the consumer circuits either to the solar controller output or to this power supply.

Works like a charm! Now I can go to any campsite with an external power supply and recharge the battery and at the same time still operate all my 12V devices (light, TV, refrigerator).

The power supply and the battery charger are plugged in:

The charger is charging the battery:

The line tester shows that everything in the mains line is properly wired (left picture), and the whole 240V setup is fully functional (right picture):

Reversing Camera

The view through the rear-view mirror became quite obstructed with all my construction, and when driving with luggage, it will be even worse. So I decided to put a rear-view camera in. The camera already crates a reversed image, like a mirror. This image is then shown on a small monitor above the real rear-view mirror.

I did not want to drill any more holes into the vehicle, so I decided to mount the camera inside of the vehicle. One disadvantage is that it has to look through the tinted rear window, which means that the image is darker, and at night it is basically not usable, except when other cars are there with their headlights. But this is ok - the real mirror is also not better.

Using the Microwave Oven: Boiling Water, and Eggs

For a while now I have driven around with the Microwave in the back. I had tested it right after Christmas, when I cooked one of those meals specifically made for microwave cooking. It had worked fine, but now I wanted to do a more thorough testing.

So I decided to heat 0.5l of water and observe the boiling process. The microwave oven is specifically manufactured for use in a motorhome and therefore does have less power than any usual household microwave oven. This is because campsites often only provide limited electric power, sometimes only 4A at 240V, which is around 1kW. The heating power of this microwave oven is 425W, compared to 700W or more for a small household oven. Therefore, it is to be expected that the boiling duration would take longer. Also, this has to be considered when cooking meals: the times given for certain microwave powers need to be extended for use with this oven.

0.5l is quite a large amount. This is about 3 cups of coffee/tea and is sufficient for any soup that I would want to cook. I measured 0.5l, then used a microwaveable cup to heat the water.

Then I heated the water in intervals and measured the surface temperature with a remote infrared thermometer. The plot of the temperature rise is shown here:

The graphs seems not to show that the water is brought to a boil - but actually the water was boiling in the end, blubbering, even though the surface temperature seemed not to increase beyond 87 C.


The next experiment was to boil eggs. Usually eggs are very difficult to boil in a microwave oven: the power needs to be deliberately reduced to achieve a slow cooking. Here is where the reduced power of this oven becomes really useful. I used a plastic egg boiling container specifically made for microwave cooking.

To avoid that an explosion would throw egg around in the oven I affixed the top cover with a rubber band.

After about 45 seconds of heating I heard an explosion. Nothing really happened, just the egg cracked a bit. I took it out after 1 minute, and here is how it looked:

Not yet fully hard-cooked, the egg white was still partially transparent. So I boiled it for another minute. Here is how it looked then:

Well done, a hard-boiled egg in 2 minutes!


The next experiment was to boil 2 eggs in the special microwave cooking device which my friend Falk had given me a few years ago (knowing my cooking style). This is a plastic container in which one can either cook 2 eggs or one slice of bacon.

I opened 2 eggs, one in each of the compartments, as shown in the picture above. After 45 seconds there was again an explosion. Here is how they looked after 1 minute:

Only the right one seemed to be done, whereas the left one remained uncooked. After another minute the result was this:

Clearly there was an issue with the internal distribution of the microwaves: apparently the power was stronger in the right part of the oven. I ate the well-done egg and boiled again the not-yet-boiled one, for 1:30 min. Perfectly done then!


My final experiment for the day was to boil again two eggs, this time just switching sides after 1 minute. Did this, and after the rotation I did cook them for another minute.

They tasted excellent!

The next step: Microwave Oven

Slowly the equipment in the MicroCamper gets completed. What was missing up to now is a cooking facility. I had put the coffee maker onto the work board, but that had to be shifted due to space restrictions - it will be again mounted on a slightly different location. But there is another item which my brother Winfried gave me as a present: a microwave oven specifically for campervans! Its specific features are a low power, so that it can be operated in low current settings, for example on camp sites which only provide a few Amps. any regular microwave oven would blow the fuses at those sites, but this microwave oven does not.

I already had cooked a ready-made meal in it a few months ago, but now it is time to do a real-world test in the actual camper.

So far I only have placed it in its location, affixed with a bungee cord. Will have to do some actual cooking soon. I will first use only its main connection, which can be a standard 220-240V mains power. It also has two battery-powered modes, which sound a bit scary: the "low power" setting will draw 20A from the 12V battery, and it will produces 100W microwave power. The 20A will move my electric system close to its 30A limit - I will have to watch that I do not blow it. Also, the cooking / boiling will take a while in this low power setting; I will take some measurements on how long it takes to heat up a cup of water to the boiling point.
There is the other, "high power" setting for using the battery. And that one will draw a full 55A. Cannot run this through my electronics, but will have to connect it directly to the battery. With the car alternator connected and running. Am a bit afraid of that test....

In any case, for both tests the leisure battery will need to be fully charged, as after these tests it will most likely be fully drained.

Installing the TV

Another important item: the TV. This is a 22" 1080p TV, with built-in DVD player and SAT receiver. I mounted it on a flexible arm, so it can be moved to the side when not needed.

The TV is quite heavy, and through the extended arm there is quite a lot of pressure at the mounting. I knew that the simple laminate board would not be able to hold the TV just by screws drilled into it, so I added a support beam at the other side of the board which would distribute the pressure onto a wider surface. Unfortunately that beam did move a little when I drilled the holes, therefore it is not exactly straight. But at least I think that it is stable enough to hold the TV also through the vibrations that occur during driving.

In my opinion the 22" screen has a reasonable size for this vehicle. I would not want anything smaller, and for a larger display there is no space. This TV also has an HDMI input which I will use for the Raspberry Pi which will eventually be installed here as a "vehicle computer".

While setting up the TV, the reception of the digital TV signal was not very great. I have to try it again in the open field, with good view of a TV tower.

When on, the TV draws from the 12V power a current of 2.2A. This may go up to 3A when DVD or SAT is used - the rating of this TV is 37W. When in standby, the TV uses 190mA. But it also can be switched off completely.

A heavy-duty electric socket/plug

For working on the electrics I have to take that board with all the switches and cables out of the car. It has been easy to remove - just one screw at the top, and I could take the board out and work on improving the electrics. But everytime I took the board out, I also had to unscrew several electric connections: vehicle ground, vehicle battery, leisure +/-, solar panel +/-, lamps. The cables are not getting better from often removing them form the screw-terminals, so I was considering to use plugs instead. I found several connectors at Maplin which were suitable for the lighting connections (ok for 6A) and the solar panel connection (20A is sufficient, as I have seen never more than 6A coming from the solar panel). But I was not able to find a suitable socket and plug for the battery: I have designed everything to be able to support at least 30A (solar controller, thick cables, circuit breakers). Therefore I was looking on ebay, and I found one, shipped directly from China: a heavy duty connector with four pins, used foe 380V and permitting 30A.

This connector is also waterproof. So I connected the leads from the two batteries into the socket, and connected the plug to the board.

Now it takes much shorter to get the board out: simply unplug all the connectors, remove the one tightening screw, and the board can be removed.

And while at it, I also added a cover board to hide the cabling out of the view. And improved the attachment of the board: now with two screws (one at the bottom onto the work surface, the other on the top onto the shelf.

The second bed

For the second bed (on the right side of the vehicle) I first needed to construct the base. This base sits on the larger folded half of the rear bench, which is two seats wide. Due to inaccuracies and a slightly sloping and soft surface of this folded bench it was difficult to get this base straight in line with the already existing bench on the left side (which only covers one folded seat).

This base I did leave more open, so that I would be able to access it to store content, even when the bed is covering it on top. But this also meant that the sides would be inherently less stable, as they would not support each other through right-angle mounting of the side walls. Therefore I put a horizontal bar at the top of the base, which would connect the front and rear walls and also would provide the support for the bed to be on top.

This support is also used to stabilise the bed board on top by fitting between two other support beams which form a grove into which this support bar can fit.

Now there are two beds usable in the MicroCamper. When folded, the bed boards fit behind the driver seat, as shown in the picture below:

The first bed

The next milestone was to complete one of the bed supports. This is made of two MDF boards which are connected via a piano hinge so that it can be folded. The total length of this first bed is 1.85 m, the width is 0.60 m. I had to cut out some parts on the side where the board touches the vehicle wall. Also, towards the end, the vehicle is tapered somewhat, so the board also becomes more narrow. This would be just a kind of "emergency" bed, due to the quite small size. But it fits in the back with even the passenger seat in its regular position.

In the back there is one foldable support leg, which supports the weight of the person on the bed. When folded, the bed support is just 95 cm long and can be stacked away either vertically behind the driver seat or horizontally onto the folded rear right seat bench.

Left-side support module

The first of the bed support modules is now completed. I covered the base platform with vehicle trim (affixed by glue and by stapler gun), then put two beech laminate furniture boards on top as the walls which would provide storage and would support the bed board on its top. This module can be placed onto the left folded rear seat, while the right part of the rear bench can still be used for seating passengers. This will allow a single bed being used with only that single rear seat being folded.