This project was originally about providing a cost effective mobile platform for digital media capture – still images, video and sound. At the time I was also thinking it would be good for /P operation! It is the perfect vehicle to solar powered QRP.
I need to be able to travel in the UK to remote locations and stay for several days without access to the usual services. There is a need for somewhere to sleep, cook meals, relax and of course do the work required for safe digital capture including images, sound files and video. The ideal solution would be small camper van with provision for charging batteries and internet access for uploading to a cloud server and social media.
Basic specification for the autonomous digital capture vehicle – ADCV
- Room to sleep 1 or 2 people
- Be completely self-contained i.e. not reliant on:
- Be cost effective
- Have the minimum environmental impact possible
With a very limited budget, even a small camper van was out of reach. The answer was an Amdro Boot Jump which is a basically a slide in unit with compartments for a spirit stove on one side and storage boxes on the other. It can be configured in either day mode which provides a small table and bench seating or extended into a bed. I chose the version with the Vaude awning which gives more room on longer trips.
The Boot Jump is lifted into the boot area of my Peugeot Partner and clamped in place. There are no modifications to the vehicle and it can be removed in a few minutes. With the rear parcel shelf in place it is impossible to see that there is anything in the car – or ‘the van’ as it is now called.
Next came the requirements for the electrics for the charging batteries in capture equipment, laptop, phone, and other electronics. I decided to use a separate leisure battery to avoid accidental flattening the vehicle battery. The overall design criteria for the project was that there should be no modifications to the vehicle and that everything could be easily removed.
As I need a lot of storage space for extended trips I decided to remove the rear seats when travelling which takes a couple of minutes as they use the Isofix system. I could then use the bed partially unfolded. This gives space under the bed for everything that I need. There is also more storage space behind the front seats.
For the power supply, I chose a single 75AH battery for summer use and plan to use two for spring and autumn. This gives more flexibility than a single large battery and reduces the weight when the dual battery is not used. The battery can only be installed in the van when the rear seats are removed.
It is important to use sealed batteries inside the car to limit spillage of acid. Although not totally spill proof they are better than the old-style version with top up caps. For extra safety, I chose to use standard battery boxes as they are cheap and will keep any minor spillages contained. They also protect the top of the battery from possible short circuits which can easly cause fires. I made a shaped base plate that fitted with the end of the Boot Jump. This helps to keep the battery in place. When I need to add the second battery I plan on making a new base plate that covers the full width of the vehicle and is screwed into the attachment points for the cargo D rings on either side.
- Battery charging for all devices.
- Mains power for camera battery charger and small fan heater
- Laptop charger – 19V DC
- Mobile WiFi hotspot and internet connection
Most portable electronics use USB chargers and there are several small 12V to 5V USB converters on the market often with multiple outlets. I chose one with twin outlets and fixed it to the side of the 12V distribution board.
The charger for camera batteries is a mains only switch mode power supply which needed a 300W pure sine wave inverter. The Inverter is now fixed the rear of the Boot Jump below where the small fan heater on the rear parcel shelf. The inverter is controlled by a relay and switched from the small black box.
The solution to getting 19V DC at 3.5A for charging the laptop was a Buck Converter which takes 12V input and converts it to 19V. This is a more efficient system that avoids the use of 12V to 240V inverter.
I have installed two LED strip lights on the roof lining towards the rear of the van. There are independently switched and fed from the distribution box.
Heating is a major energy supply issue. There are several gas powered and some spirit powered heaters around but I did not want an open flame in the van because of the fire risk, carbon monoxide and condensation. That leaves electrical heaters using a ceramic element. The 12V versions have bad reviews in terms of effectiveness. For emergency use I decided on a small 150W/300W, 240V fan heater which can be run off the inverter for short periods. It was more than adequate during tests on a cold spring night.
Charging is via an 80W foldup solar panel. This gives around 4.3A in full sun. It was made in Germany and sourced from a UK supplier. It came with a solar charge controller which is essential.
The feed from the battery goes through a cheap (ebay) battery monitor which shows voltage and current. If the solar panels are attached the ‘charging’ light on the charge controller comes on and the current readout shows total charge if there is nothing else connected. (The battery monitor has now been changed to slightly better version which shows energy used as well as battery voltage.)
The distribution board, a PowerPole®, Fused DC Connector Box, came from Sotabeams. Each outlet is separately fused which is essential. The two outlet USB charger module is mounted on the side of the distribution board below.
The feed from the battery to the distribution board has a 30A inline fuse as does the separate feed to the inverter. This is crucial as a short on the battery could easily cause a fire. The potential short circuit current could be above 1000A which is enough to cause the cable to glow red hot and melt.
Precautions need to be taken when charging lead acid batteries. DO NOT OVERCHARGE. Modern chargers switch themselves off when the battery if fully charged. Do not use old chargers without such protection. And remember that charging from any source produces hydrogen gas so vent the space to avoid a build up. See this page for battery safety advice
The feed from the battery uses 43A twin cable and 80A connectors. If the wires feel warm in normal use it is too thin and you will be getting a voltage drop between the battery and the appliance. Do not use 30A mains wiring as it is not thick enough. Use the correct automotive wire.
The mobile WiFi and internet connection are provided by a TP-Link 4GLite which uses a data only SIM card and connects to the 3G network. With a good connection speeds are higher than a BT fibre broadband. Similar units are available for different networks.
I did make a very small modification to the vehicle by installing a button to open the hatch back from the inside. See this video for instructions
Camping sanitation is not an issue these days, there are a variety of portable flush toilets on the market. I also carry a folding spade just in case!
Overall the van works well and is flexible enough for what I want. I do plan some changes during the summer but they will be minor tweaks.
Modifications – May 2017
The night and early mornings are still very cold which means some form of heating is essential.
- Make a plywood base plate that covers the whole width of the van and can contain a second battery.
- Wire second battery in parallel with #1 using 60A, 2 pole connectors to allow running on either one or two batteries.
- Install a new charge/discharge meter that uses a single 60A shunt. This will show total current drawn by everything from either 1 or 2 batteries and give a more accurate indication of remaining charge.
A useful way of assessing battery charge.
Update Auguest – 2017
The inverter was moved to the back of the Boot Jump to save space on the floor under the bed.
A new battery monitor was installed that shows total current drawn from either a single battery or two wired in parallel.
New lighting consisting of two LED units which are independently switched.
Next, a micro wind turbine!
After a heavy drain on the battery wait 20-30 minutes before checking the voltage. The battery needs time to recover.
|State of Charge||Voltage|