This project has been a long time in the making – for the last few years, I’ve been encountering more and more charging stations with fixed cables off which I cannot charge with my trusty, 10+ year-old, Type2 cable.

More and more the norm
More and more the norm

There would be a very, very cheap way to solve this problem: the reason why you cannot just plug another Type2 cable into the plug from the charging station, effectively making cable extensions impossible is the shorter CP pin on the ‘plug’/’male’ side of the Type2 specification.

The second reason for this is to ensure all other pins are seated before any power is provided by the charging station or communications take place.

There are a multitude of TWIKE pilots already using this hack of a solution:

Long CP-pin solution in TWIKE
Long CP-pin solution in a TWIKE
Professional Charging - this is what I want
Professional Charging – this is what I want
Oh, this could be so easy and cheap...
Oh, this could be so easy and cheap…

But anyone who knows me: this isn’t an option. I want a beautiful, durable, fancy solution to this problem!

In summary:

I want to upgrade TW560 to have an own car-like receptacle for charging from cable-only charging stations.

With this, I started to research options for such a box (knowing full well that I could just go to dreifels and purchase such a box with full controller integration for CHF 1,120 plus 3 hours worth of work. It’s a beautifully super over-engineered solution to this problem.)

I don’t need the fancy integration and display capability, my existing chargers don’t allow for CAN configuration and dreifels’ plug placement and changes don’t work with my current 2-charger setup without major reconfiguration.

My solution should just allow for a cable to be plugged into the TWIKE, start the charge, allow for connecting both external chargers permanently via blue CEE plugs and have a third CEE plug which gets used by the CEE connection coming from the original inverter.

Ideally, the box fits without any further adaptations required and can be removed without any tools to allow for it to be shared with others or used to power other things from a commercial charging station.

After some short research I came across this description from a fellow TWIKE pilot from Weilerswist. It’s practically the box I envisioned.

The inspiration for my box
The inspiration for my box

Great, now let’s flesh out how mine will look like physically!

There is a 15 cm space between the leftmost charger and the wheel arch. This seems to be a perfect place to position the box as the cables from the chargers will route to the box directly without any additional extensions required.

My idea is to have two blue CEE plugs on the front of the box and the Type 2 and additional plug on the front face, complete with the switches.

Time to start ordering! (see BOM at the end of this entry for all details on where and how to order)

The box needs to be as water and dust resistant as possible. The box I found has a gasket all the way and seems sturdy.

The box the adapter will be placed in
The box the adapter will be placed in
The Type2 socket I bought
The Type2 socket I bought

With the two most important parts sourced I waited until the box arrived as I was unsure how brittle/sturdy the transparent cover of the box is.

Finally, the box has arrived: #gogogo
Finally, the box has arrived: #gogogo

Just as I suspected, the plastic cover is very thin and brittle and does not at all look like it could withstand any kind of forces such as plugging in huge Type2 plugs. I will need to add another layer above the clear plastic. I’m thinking a sturdy 5mm sheet of plexiglass.

Project sketching on newly-received box
Project sketching on newly-received box

I start sketching out the positions of the various plugs. Thankfully, all is good. everything, especially the two front plugs positions are perfect.

Holes, plastic to be removed, plug overlaps etc.
Holes, plastic to be removed, plug overlaps etc.

Time to queue the music and move to a place where I can do the required work without bothering anybody else! Lucky me: I have just the place!

Where all the good stuff happens :)
Where all the good stuff happens 🙂

I start sawing out the larger holes with my jigsaw and drilling holes for the screws.

Everything just lines up!
Everything just lines up!

The sturdy front cover turned out to be a 5mm thick sheet of plexiglass. I cut out the same holes there, too.

They don't have to look nice...
They don’t have to look nice…

Every plug and opening gets checked if the plugs actually fit.

Looking good!
Looking good!
Positioning of plugs and gaskets
Positioning of plugs and gaskets
Pre-paint
Pre-paint

I then get the cables ready – 2.5mm * 5: Ground, Neutral, Phase 1, 2 and 3. 2 * 28 AWG for signalling.

Luckily, I have quite a few metres left over from other projects around the house!

Didn't have to buy any of therse...
Didn’t have to buy any of therse…

A few minutes later – ready for the next steps

Ready for soldering
Ready for soldering

Time to solder the pins on!

Soldered Pins, ready for assembly in plug
Soldered Pins, ready for assembly in plug

It’s then time to start with the electronics – they are dead easy, essentially just signalling vehicle presence and charge readiness plus how much max current the vehicle will be requiring. I have decided to choose the 680 Ohm 20A max limit as my vehicle will never require more than 16A.

From another Type2 project I worked on over 10 years ago, I still had the original Mennekes plug specifications ready:

My fellow TWIKE pilot’s project schematics are fully in-line with this:

Cabling and Switching within the box
Cabling and Switching within the box

That said, the box in its V1 configuration will not be able to react to charge current limits coming from charging stations – these are getting more and more prevalent as means to balance a maximum load when there are multiple charging stations – a setup which is getting more and more common these days.

The functionality to actually reduce the charge will require new chargers which can be controlled via a CAN bus and a micro controller (which I’ve already done for the TWIKE) and the challenge of somehow changing the max charge rate of the TWIKE inverter …maybe via the Dreifels controller or directly via RS485? V2 will have many interesting challenges!)

The proto-PCB I found has holes for screw mounting which match perfectly with the ones present in the box.

PCB Proto Board with Mounting Screw Holes
PCB Proto Board with Mounting Screw Holes

The contacts to the outside world are via screw terminals.

Blue screw terminals
Blue screw terminals

I then spray the whole box black as I want to mask the different colours and materials before starting assembly of the box, starting with the main Type2 plug.

Socket assembly
Socket assembly

Since I’m a sucker for nice cabling, even it it isn’t visible!

From above
From above

Here you can see two very small cables (phase and neutral) going back to the top of the Type2 connector – this is a small led that lights to indicate when the connector delivers electricity.

Turned out pretty nicely
Turned out pretty nicely

The proto-PCB finds a nice place in the bottom part of the box.

Proto board II
Proto board II
Control Electronics on PCB proto board
Control Electronics on PCB proto board

A last check if all is good before closing the box:

I'm a sucker for tidy cable management
I’m a sucker for tidy cable management

Time to close the box and add the last screws!

So looking forward to testing!
So looking forward to testing!
Closed box, ready for testing
Closed box, ready for testing

Time to test!

Thankfully, for a preliminary test, I have professional 22kW Type2 charging station from Mennekes itself available at home. Since, electrically, there will be no real difference between having a cable-only charging station and one with a plug and I then bridge the gap, so to say, by using a Type2 cable, I should be able to confirm if the box itself works or not.

So, to the cold outside I head!

Let's test the box!
Let’s test the box!

Let’s plug in the cable!

The box in action
The box in action

With the box connected to the cable and the cable plugged into the charging station comes crunch time: will it work?

Success!
Success!

YES! The sweet, sweet sound of relays clicking and screens showing kilowatt hours!!!

See how this test looked like live! See the video below.

Now to where the box will be living in the TWIKE –

The Box has found its place! Cables to additional chargers will be connected permanently
The Box has found its place! Cables to additional chargers will be connected permanently

The box needs to be lowered by a few cm.

A task that I will complete when extensive testing has taken place.

Now to the pièce de résistance! A charge at a cable-only charging station! Here we go!

It turned out to be quite a feat to find a charging station with a cable attached close to where I live. Most of the ones I know have been replaced by either CCS or a small plug-only solution

15km away I found one at Kaiserstuhl railway station.

Arriving at charging station
Arriving at charging station

I then plug in the 3 leads from the TWIKE into the box together with the charging cable from the charging station.

Ready for charging
Ready for charging

Then I fire up the app and scan the QR code – Swisscharge does not require you to have an account to start charging! Just provide your credit card details and you’re good to go! Very nice!

Scan & go
Scan & go

The app is then installed and the appropriate charging station is selected – smooth experience indeed!

I swipe to charge and then flip the switches on the box …and bob’s your uncle!

It works!
It works!

My TWIKE looks really grown-up charging like this – I’m very happy.

Looking professional!
Looking professional!

Just 18 mins later after a quick stroll to the medieval tower – Kaiserstuhl’s main visual feature – I’m back to the TWIKE and 1.433 kWh more in my battery.

18 mins for 1.433kWh, totalling €0.65
18 mins for 1.433kWh, totalling €0.65

With this it’s time for a final re-cap – I’m really happy with how the project turned out!

This box will help me not only with cable-only charging stations but also allow me to do away with the fiddly cable solution I had until now.

There is, however, another challenge on the horizon: the demise of AC charging altogether. Many of the charging stations in Switzerland are now either CCS & Chademo or CCS-only. Even smaller 20kW ones are now CCS-based.

Since CCS is a completely different beast – complexity, component pricing and DC-based, I think making such a connection with a TWIKE will be a little more difficult than this project 😉 We’ll see.

Maybe I can find a fully assembled CCS front-end block which handles all the communication and other stuff whilst I only provide the block with DC or maybe some other form of control signals. Stay tuned.

For those of you who want to build your own – please find my BOM below, complete with cost per item and where relevant, link to the seller. I am very happy with the total price. Since I already had some of the components, the price might vary slightly for you.

Bill of Material:

Pic Item Description Amount Cost per item Total Cost
Transparent Plastic Enclosure from AliExpress 1 CHF 14.24 CHF 14.24
16A 32A Single or Three Phase EV Charger Socket Type 2 Iec 62196 EVSE for Electric Vehicle Outlet from AliExpress 1 CHF 37.79 CHF 37.79
A CEE16 one-phase socket for mounting Sourced at Pusterla Electronic 3 CHF 10.65 CHF 31.95
Cable Management Adhesive Mount Points 1 CHF 7 CHF 7
Small screws for mounting the PCB 1 CHF 5.50 CHF 5.50
Plexi Cover for Box 5mm 1 CHF 21 CHF 21
Black Spray Paint 1 CHF 19 CHF 19
Plastic Primer Spray 1 CHF 18 CHF 18
Small washers for PCB mounting 1 CHF 6.50 CHF 6.50
Locking Nuts 1 CHF 5.50 CHF 5.50
Spring Washers CHF 5.50 CHf 5.50
Washers 1 CHF 5.50 CHF 5.50
Countersunk Screws 1 CHF 6.50 CHF 6.50
Countersunk Screws for the box (M4, long) 1 CHF 6.50 CHF 6.50
PCB Proto Board with Mounting Screw Holes 1 CHF 4.50 CHF 4.50
2.5mm wire 5 CHF 0.00 CHF 0.00
Set of multicoloured fine wires 1 CHF 8.00 CHF 8.00
Blue screw terminals 4 CHF 0.50 CHF 2.00
Diodes and Resistors Misc Existing Existing
On/off switch – 2 contact paths 2 CHF 2.50 CHF 5.00
Total Project BOM CHF 203.48

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