Tag: USB-C PD

Using an Autoterm 2D heater with a Baseus 100W USB-C PD power bank

Some years ago, we bought a Autoterm 2D diesel heater with a waterproof box. This heater actually needs an external 12V power supply (or a 24V power supply, depending on the model you buy). Until now, we always connected this to one of our 12V leisure batteries. That meant we always had to carry a long 12V extension cable with us. Not any more …

Since we had such a good experience with our mobile shower via USB-C that originally also runs on 12V, I went looking for more devices with a 3A @ 12V power requirement. And according to the data sheet Autoterm 2D just is such a device. The manual states a power requirement from 10W (min 800W heating power and 34m3/h) to 29W (max, at 1800W and 75m3/h).

So, I got myself a Baseus 100W Power Bank 20Ah from Aliexpress that can deliver the required power. With this unit the diesel pump can be powered for approx 2.5h at full capacity and approx 7.5h at minimum capacity.

Actually, any power bank with USB-C PD that delivers 3A @ 12V could be used. And if you take a power bank with a higher capacity the heater will certainly run longer.

Baseus 100W Power Bank 20000mAh Type C PD, taken from https://www.aliexpress.com

Connecting the heater to the power bank is done in the same way we connected the mobile shower. Again, with the help of Aliexpress: USB C PD Type C Male to 12V Car Cigarette Lighter Socket

USB C PD Type C Male to 12V Car Cigarette Lighter Socket, taken from Aliexpress

In my opinion, the advantages of this approach are:

  1. Flexibility: we can carry the power bank along with the heater and do not need to keep a 12V power source (leisure battery or else) nearby. An option to power a power bank is probably easier to find than a 12V source. Especially true for our trailer with a 24V battery.
  2. Price; power bank is around 51CHF and the converter 5CHF (and the battery 1700CHF) . Compared to the other heater we have, the Profidurium Mobile-Heater 2kW, this is much cheaper. The additional battery with charger costs an additional hefty 970CHF (on top of the 2300CHF for their heater).
  3. Weight: 400g for a power bank is a neglectable additional weight compared to a full blown battery.

Quick review of our 12V USB-C mobile shower

Last December we wrote about our plans for a mobile shower. And today, I describe show how it actually works.

We currently use the shower, Brunner Aquafresh 2.0, in our Caravan instead of the built-in shower with the boiler to reduce the risk of legionellae and to conserve power.

We heat the water with a 2000W immersion heater which takes around 25min to heat the water to 43°C from 15°C (see the post linked above for more details on time and power requirements). And make sure to stir the water after heating before use.

The water is kept in a DIN96 20l wide-neck container from Comet with a special dust 2-hole cap to fit the hose and the elecitricity cable into it. The pump itself has a standard 12V car/cigarette plug that connects to a USB-C trigger board that takes it power from a USB-C power bank with Power Distribution (PD) 2.0.

Everything is kept within a 30mm PIR tube and glued together with hot glue. This does not look to nice but it works. To further “water proof” the device I keep it in a plastic zip-lock bag with the opeining upside down. See below for an even easier option for this.

The on/off-switch on the shower itself is not waterproof – but until never got too much water to produce a short.

To actually get the hose and the electricity cable through the plastic cap of the container I cut away the switch (as it could not be opened) and connected a new one (from Steffen, bought at Landi for 1,50 CHF).

The power bank must be able to deliver 3A @ 12V (the pump has a nominal power consumption of 35W). Water pressure is ok, but not great. Two people can consecutively shower from a 20l container (without washing long hair, of course).

Video: Quick review of our 12V USB-C mobile shower

We also use it in our cars as a mobile shower. On the road we only have a 1000W immersion heater, so heating up the water takes twice as long. But in the summer the initial temperature is much higher so it slightly compensates the total time needed.

UPDATE: instead of going through the hassle to build a USB-C to 12V converter yourself, you can also buy this item from Aliexpress. It is a sealed USB-C to 12V converter. It is much smaller than the tube-based device and costs only around 5CHF, but has no fuse.

Note, that there is a version with and without converter. I went for the version with the converter and with a cable length of 300mm.

USB C PD Type C Male to 12V Car Cigarette Lighter Socket, image from aliexpress.com