Newbie and EV chargers

Hello all, I've read lots and lots of posts on here and elsewhere about chargers but would appreciate it if my logic could be checked! I'm not technical enough to get into using APIs and programming so I'm looking at things in simple terms 🙂

So ordering a PHEV now and probably a full EV in the next year. Current set up 7.2kWh PV going to a GIvEnergy 9.5 battery, installed in late December. Ideal roof and 6kWh inverter on the PV so already seeing export of up to 10kWh some days. Assuming I'll be getting a 7.6kWh EV charger. Cars will be at home to charge at least 4 days a week.

Looks like my options are - (1) have a smart but not solar friendly charge point - in winter charge car at night at the same time I'm charging the battery on EV tariff - will ensure I don't run the battery down. In summer manually start charging when battery is full and the solar is good, charger would take 6kWh (or whatever they are exporting) from the panels but then 1.6kWh from the battery as the charger will be "seen" as house load. I then have to judge if there will be enough solar to get the car and the battery where I want them during any specific day... and if I discharge the battery fully doing this the top up to get to the 7.6kWh will be at my peak rate.

(2) get a Zappi use it on timed charging in the winter at the same time as the battery (per above) and then on a good solar day follow the guidance to set it on Eco+ and with the right CT clamps it will "see" and use any excess being exported and only use that without draining the battery or drawing from the grid at my peak rate.

(3) Wait until the last minute to see if the GivEnergy EV chargers gets rolled out...

Any major flaws in my logic? Thanks very much!

Pitva in my case I have 6.2 kw PV and the best day I have ever seen is 42 kw in April last year, not quite enough to completely charge my 45 kw EV battery. The problem is that your panels are actually very efficient in the cold of winter and less so in the hot summer, so while summer production is better due to longer days and higher sun angles it’s not all good. The upshot is that unless you do very low mileage, with 2 cars to charge and a house to run your PV will simply be supplementing your grid usage. If you can wait for the same charger as your system I would to avoid further issues with say your cars discharging your house battery. Hope that helps!

If you are initially getting a phev I would use a granny charger until you get a bev and then hopefully the GE charger will be available which should fully integrate into your system.

I do not know about all PHEVs, but my experience of the VW Passat is that it is limited to a maximum charge rate of 3.6 kW, and the usual low limit set by the charging standard of 1.4 kW. It took close to 4 hours to fully charge 11.x kWh from empty.

If you are ordering now, how long is the lead time for the car(s). My new EV took 1 year to the day from order to actual delivery.

With the Zappi you can set a device limit (in Amps). Mine is currently set at 22.6 A (around 5 kW) as an experiment in EV charging efficiency.

Option (1) will take a lot of manual input, bearing in mind varying solar output as clouds pass over.

Your option (2) is sound, and certainly how mine works.

Option (3) could be in for a long wait, based on current lead times for Gen2 hybrid inverters.

Thanks both, a granny charger wouldn't quite work as I have a 4 hour EV rate. The PHEV delivery is being quoted as June/July and then I'm hoping one of us will get an EV lease scheme from work at some point. I like the idea of limiting the zappi to around 5kWh (didn't know that was an option) as that's the minimum I'd expect on a good sunny day.

Good to know I've understood the basics, thanks!

Pitva I like the idea of limiting the zappi to around 5kWh

The Zappi will divert all your surplus PV using the supplied CT dynamically. If your surplus is 4kW, the Zappi will divert that to charge the EV. If a cloud comes over and surplus drops to 2kW, the Zappi will reduce charge to the vehicle. If surplus falls below 1.4kW, the Zappi will pause charging and that surplus will be exported if you have it in ECO+ mode with 100% Minimum Green Level. If you reduce MGL to less than 100%, it will blend surplus PV and grid import to maintain 1.4kW charge rate or higher if surplus increases.

You can add CTs to monitor output from your PV system so it shows in the MyEnergi app and you can also add a CT to your Zappi supply cable so that the current drawn is limited to whatever value you wish. This would work when you have say a 6mm/40A supply to the garage but you have the Zappi and other equipment supplied from there (maybe a granny charger socket or a tumble dryer etc). You would limit the current drawn on the cable to 40A, so the Zappi would reduce its 32A maximum draw if your granny charger was drawing 13A off the same supply. The Zappi is here now and does offer a lot of features. The Givenergy EV charger is much promised and may work as well, or not. We don't yet know. There are other EV charger manufacturers out there who may also offer as much functionality as the Zappi but if you're wanting to invest in an EV charger, you could do worse than a Zappi.

As an aside, we have friends who have had two EVs for years. They just work out which car needs charging when and only ever use one EV charger.

Thanks Tim, that's useful info - I'll see what sort of quotes I can get for a Zappi and maybe an Eddi at the same time whilst I'm at it.

With a PHEV and it being home for over half the week it's probably not even worth getting a 7.2kWh charger. Get a dedicated 13 amp socket wired in and use the "granny" charger. A dedicated EVSE charge point will give you more future-proofing, but at this point, given what you have said, it is almost certainly not needed.

I use an Andersen and it also can be set up to use excess solar to charge the car. I have 5.2kWp of solar generation (best generation day last year was 40kWh) which will mainly go into the 16kWh battery storage. After that, excess goes into the hot water. only then do I start chucking anything into the cars (2 x BEVs with a single charger).

Zakalwe Thanks and yes I could see how I do over the summer with just an Eddi for the excess to start off with as being free of using any gas for 6 to 8 months is appealing!