arnolde wrote: ↑
Tue Nov 12, 2019 5:08 am
Has there been any new progress yet? I have a 7.7kWp solar generator and 2 EV's with Chademo sockets, I'd love to experiment with DC charging. Since I already have 400-800V DC readily available, I "only" need to solve these 2 tasks:
a) CAN messaging
b) how exactly does the EVSE need to regulate the voltage/current going to the EV?
The only downside to this approach is that I won't get any money for the self-usage of electricity, since it wouldnt go through the "pv generated" meter. The upside is that it's much more efficient than converting to 230VAC and then back to DC.
I don't understand yet what exactly makes "the DC charger circuit" sooo expensive (several 1000 EUR), can anyone explain? Seems to me any owner of a 400V 3-phase supply can simply rectify that to get 400VDC and then use that to charge the 350VDC EV battery simply by limiting current&voltage, which at 30A can't be THAT complicated? Isn't it the same as any voltage/current regulating lab power supply does, just with a larger power stage? And microprocessor controlled?
Being a US home owner, 240 VAC is the only practical grid voltage available. Both SolarEdge (StorEdge) and Pika Energy have commercial solutions for hybrid energy converters that are grid tied, of course have MPPT PV inputs, and work seamlessly with high voltage Li battery systems (wall type). These battery systems can of course provide backup energy in grid failure scenarios.
I've tried working with Pika as they have communications systems for other OEM battery systems. However, they are not willing to take on the CHAdeMO protocols as they believe it is too limited in use AND they don't have the bandwidth to support.
IMO, there will be at least two offerings that have (likely expensive) solutions similar to what we want this year - we will see.
In my situation, any PV energy used to charge my Leaf will back out full value of a kWh of grid supply - the best I can do as I only get the energy cost (about half) if I have excess energy to return to the grid.
2012 Leaf SL; 43,000 miles. Battery replaced November 1st, 2016.