openinverter forum

Good morning everybody from Greece,

I am new at your forum, dont know too much and i will apreciate your help if you can offer to me .
One of my customers, need a movable DC Charger to power up empty electric car batteries that cant be moved .
So he needs to charged them just a littkle bit and then drive them to a stable charger for the rest of charging .
Is there someone that could help me find what do i need to build it ?

Do you think of CCS? Or Chademo? Is AC charging no option?

There are open source CCS controllers on car's side. If anyone made one for charger side, it could be possible to use onboard AC chargers as a DC source.
AC power source -> stack of OBC chargers -> CCS Comms-> vehicle. So basically unlimited power (and limited voltage by OBC hardware)

sounds like he needs a small petrol genny with a granny charger, saw a vid where a guy used a genny on his stranded tesla he only needed a couple of miles to get to the charging station

apolyshow wrote: ↑Mon Feb 16, 2026 11:16 am Good morning everybody from Greece,

I am new at your forum, dont know too much and i will apreciate your help if you can offer to me .
One of my customers, need a movable DC Charger to power up empty electric car batteries that cant be moved .
So he needs to charged them just a littkle bit and then drive them to a stable charger for the rest of charging .
Is there someone that could help me find what do i need to build it ?

Do you want to make it yourself, or buy it?

0tik wrote: ↑Tue Feb 17, 2026 8:25 pm There are open source CCS controllers on car's side. If anyone made one for charger side, it could be possible to use onboard AC chargers as a DC source.
AC power source -> stack of OBC chargers -> CCS Comms-> vehicle. So basically unlimited power (and limited voltage by OBC hardware)

The open source solution for the charger side exists: FoccciCape on a beaglebone running pyPLC. As starting point e.g. github.com/uhi22/DiDeBoCCS

Oh my god this is brilliant. Solves the "80% charge limit" complaint ever since first EVs rolled onto the streets. Loads of people were complaining that they can't set a limit to charge to 80% (or 50% for long term storage). If soc is being sent out by the CCS/type-1/2 socket of the car during AC charging then you can make a mitm plug or entire proprietary evse brand and make a fortune on it. Although I suspect that nowadays it could be that nobody stresses over charging to 100% anymore... Oh wait- New cars probably have this option already and old cars with chademo don't send out soc over AC port.

apolyshow wrote: ↑Mon Feb 16, 2026 11:16 am Good morning everybody from Greece,

I am new at your forum, dont know too much and i will apreciate your help if you can offer to me .
One of my customers, need a movable DC Charger to power up empty electric car batteries that cant be moved .
So he needs to charged them just a littkle bit and then drive them to a stable charger for the rest of charging .
Is there someone that could help me find what do i need to build it ?

Hi, depending on your requiremens (mainly charging power/speed), skill set and budget, there are multiple options...

Quick question to start with - why DC? could you not use the onboard AC charger in the car?
Or are you trying to charge directly a HV battery (outside of a donor vericle)? this will make it lot more complicated.

Option 1 - AC charging (based on Dala's Battery Emulator) - would allow 7kW single phase or 2okW 3 phase AC changing
- get a big enough EV battery (from the compatible list)
- battery emulator
- HV AC inverter (from the compatible list - for example 25kW Deye HV 3phase inverter)

Option 2 - DC chagring- start with the AC option as above and add commercial EV DC charger
- all of the above from option 1 (if more power is needed just add extra inverter)
- standard DC charger (like Delta DC wallbox 50KW or Evec 40kw) - you will find units from about 20KW to about 50kW

Option 3 - DC charging DYI - start with the AC option as above and add commercial EV DC charger
- all of the above from option 1 (if more power is needed just add extra inverter)
- DYI DC charger (I have built mine with Rpi using Uhi's PyPLC + Arduino DUE to control Tesla Gen 3 OBC and other bits and pieces..

The option 3 has lot of chalanges.. (I know I worked through most of them.. my solution works-ish, but its messy)