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Hi
Reading various journalists output on charging the Zoe it could easily lead the innocent public into thinking that there are different charging voltages and that the charging point – or electric pump – controls the charge to the car. Obviously some of the contributors on this forum are better informed, but I haven’t seen a ‘pinned’ technical note setting out the facts. Apologies if someone has done it and I’ve missed it.The Z0E appears to charge at 230V single phase (phase to neutral voltage) or 230V three phase (230 V AC from each phase to neutral).
(The 400V figure comes from the phase to phase voltage – sounds more powerful but it isn’t.)When the EU decided to harmonize supply voltages 230V wasn’t a standard, most supplies in Western Europe were mostly 220V or in the UK 240V. They were harmonised by calling them 230V +/- 10% (nominal) so Z0E has to work at anywhere between 206 and 255 V AC 48Hz to 63 Hz, or thereabouts.
The communication between the car’s Chameleon charge controller and the charge point presumably tells the car what current it can draw without tripping the protection circuits of the charge point. Hence the Chameleon charge controller can adapt to the electrical environment. I assume that’s why the need for the EVSE “Granny cable” in-line box, to act as the responding part of the charge point.
It seems to be able to draw between 10A single phase (2.3 kilowatt) and approximately 62.3A per phase (for 43 kilowatts). Of course I should use KVA since the power factor is unlikely to be 0, but that doesn’t help clarity.
Its a long time since I was involved in switched mode power supply design and the technology has moved on, but that’s a heck of a range of input conditions to precisely control the charging rate of a 400V battery at high current. And it explains why it is difficult to maintain charging efficiency.
Over to the experts…
I hope we end up with a correct explanation that non-tech folk – even sales executives – find helpful.
Best wishes
FredI agree with everything you wrote…
Granny cable is just a portable wallbox with fixed max current of 10A.
I think the minimum current Zoe will accept is 9A. But I would like to charge at 6A 3-phase. And I am not sure if Zoe will accept this. Probably not 🙁
Fred
Your summary of the charging system is pretty accurate. 2 pins of the charger cable are used for communication between the charger and the car to tell the car how much current it can take and for the charger to switch on the supply. The only thing that I would add is that our UK supply voltage stayed at a nominal 240V, the only difference was that the spec was effectively tightened at the upper end.
The car varies how much current it takes during the charging cycle. On my 7KW home charger the power drops to about 1KW for the final part of the charge, it does a similar thing on the rapid chargers, the current ramping down once the charge level gets to about 90%, so resist the temptation to fully charge if you want to average the best times between destinations.
As the motor controller is used for charging the car, controlling the motor and re-generative braking it actually handles an even bigger range of powers, the re-gen can be as low as 1KW! Presumably the efficiency is very low at this level.
Renault have re-designed the motor and charge controller. This has resulted in a more efficient motor but they have dropped the upper charge rate to 22KW. This was done to increase the efficiency at the lower power charging rates. The old motor and controller will still be available for those who want 43KW charging. Many of us think that dropping 43KW charging is a mistake on Renaults part. Most owners have not purchased the ESVE cable and have 7KW home chargers.
but I haven’t seen a ‘pinned’ technical note setting out the facts. Apologies if someone has done it and I’ve missed it.
Not exactly, probably the closest is if you go to the top menus and select ZOE Description then Charging.
We borrowed a Zoe from our dealer last night to check our newly installed charger.
When I got it home – I put it on to charge and it was at 80%. When I took it off (we were going out) it showed 99% with no time remaining, presumably during the balancing stage.
When we got home, I plugged it in again ready to take back to the dealer this morning. I think it was around 60% and obviously ran till it was done.
The power consumption is shown in the two attached graphs. There is obviously some issue with the current cost meter that I use, since it shows well over 7Kw that the charger is supposed to be – but it gives some idea of the drop off in the charging.
AnonymousHi Donkeh, how are you pulling the data to produce the charging graph? My charge point is fitted on wednesday (yey!) and I’d like to monitor the battery performance…
Regards
SiG:)Hi Sig,
I have one of these things. It’s setup to monitor my home energy usage and I have it connected to a Raspberry Pi to store the data and create the graphs.
D.
AnonymousAh nice. I have a pi and the … er… geekery to produce the graphs already 🙂 , might have to look into one of those…
Regards
SiG:)How did you exclude the rest of your house from the data? Or is it just so low it didn’t matter?
Hi Dan,
My house runs at a fairly steady 400 watts. Take the second graph for example – we just got home (put some lights on) – but we came in and went straight to bed. Once the charge is finished – it drops off to around 400 watts again.
To be honest – the numbers aren’t that accurate given a greater than 8Kw draw shown, from a 7Kw charger. I thought people may be more interested by the graph itself, showing the charging cycle as it tails off at the end.
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