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Discussion Starter · #1 ·
With so much sun, I have been surprised that the car wasn’t always fully charged from our Zappi (ie 90% as 2019 model waiting for new battery)
Today I saw we were exporting 2.81kW, checked the car and Zappi and found Zappi thinks the car is full, when it’s actually only on 69%. I unplugged it switched the car on and off and tried again, left it with the green light showing, then five minutes later found the same thing had happened after 0.63 kWh. Alert showing on car saying charge stopped and to check the charger.
Any ideas if this is a car problem or a Zappi one? Both have worked fine till now.
 

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Hmmm... it could be either of them :(
I would try the following:
1. Try charging a couple more times from solar. Just to make sure that charging gets terminated frequently (every session??). Repeat and repeat.
2. Use regular 7kw charging from grid (overnight if you have eg. Octopus GO??). Dump the energy and kep repeating that charging.

If slow charging from solar terminates always after certain time but charging from grid never terminates it would imply there is something wrong with Zappi or solar setup. If charging stops from both: solar and grid then it may be the car.

I sometimes get interrupted charging from rapids which is very annoying when driving long distance. Start charging, go to restaurant for 1 hour or walk so kids are not bored and then return to only see the session interrupted with eg. only 20% charge. Really annoying :mad: Explain to kids they need to wait another hour...
 

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Discussion Starter · #3 ·
Plugged it in when I got back at 3.30 and it seems to have charged ok until the surplus dropped near the 1.3kW limit, except for one reading (quarter hourly from my SolarEdge inverter interface) when it dropped to 2kW leaving 1kW being exported.
I think I'll just cross my fingers and keep an eye open for further problems, then try rompik's excellent but time-consuming protocol if I spot anything significant.
 

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@KiwiME - fair point. Zappi does not show SOC.
I wonder why is that? If DC chargers know SOC why slow home chargers don't? I don't need that feature personally but with new ToU tariffs or when electricity provider will guarantee certain level of SOC by - say 6am that would be essential, right? Or even for folks with Zappi & solar - they would use solar but also want to ensure that by morning the car is eg 70% charged.
Any other home chargers out there that get SOC from the car?
 

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Discussion Starter · #6 ·
Zappi can’t know what charge level the car is at.
True - what I meant was it showed ‘Charge complete’ which I understand as the car telling it to stop charging, which it ought only to do when it is full (ie 90% at present)
 

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AC chargers can't know SOC as that info is not available via the J1772 interface.
DC chargers use a more complex protocol which can access this information.
Some cars have an API for their telematics that can give access to SOC via the internet when AC charging
 

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@mikeselectricstuff , are we saying that there is different protocol for slow chargers and DC chargers? Even if all the information goes via the same pins in Type 2? (I dont believe any data is sent on other two fat pins in CCS)?
 

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@mikeselectricstuff , are we saying that there is different protocol for slow chargers and DC chargers? Even if all the information goes via the same pins in Type 2? (I dont believe any data is sent on other two fat pins in CCS)?
Yes, ac uses the PWM duty cycle on the CP pin to indicate current available from the EVSE, and a couple of states from the car by applying different loads.
DC CCS uses a high bandwidth protocol, Homeplug GreenPhy, which is a full-on networking protocol, also on CP.
A 5% PWM signal tells the car that the charger wants to use the CCS signalling.
 
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