Charging EV & Battery

[tjalana]

Hi,Can anyone tell me if i can charge my solar battery and electric car at same time from the grid. If i can Would I still get to charge the car at 7kw or would it reduce because house battery is charging. Have a solis inverter with a 5kw puredrive batt, zappi being installed on Friday.
would the 5k Puredrive battery be able to charge full in a 2 hour window.
How would i stop the battery when full from charging the car or does the charge setting in the Zappi stop this.

hope this makes sense what i'm asking as i've very little knowledge of this.
Thanks

 

[Eclectic]

There are various ways to accomplish not discharging the battery into the car, the easiest is to have the Zappi split off with its own CU, so the battery doesn't "see" it. Depending on what tariff you choose, you can also set the battery to charge at the same time as the car, which achieves the same object.

I have a Powerwall and "dumb" charge point, so using Octopus GO, just set car and battery to charge on the 12:30 - 04:30 cheap time slot.

 

[tjalana]

There are various ways to accomplish not discharging the battery into the car, the easiest is to have the Zappi split off with its own CU, so the battery doesn't "see" it. Depending on what tariff you choose, you can also set the battery to charge at the same time as the car, which achieves the same object.

I have a Powerwall and "dumb" charge point, so using Octopus GO, just set car and battery to charge on the 12:30 - 04:30 cheap time slot.

Thank you for the reply,so if i have the Zappi split off with its own CU,can i still use the Zappi from the solar panels on a good day(just to have the option there).would i have to adjust Zappi settings or just plug in and it will it automatically pull off the panels if prioritize.

 

[crite40]

Hi,Can anyone tell me if i can charge my solar battery and electric car at same time from the grid. If i can Would I still get to charge the car at 7kw or would it reduce because house battery is charging. Have a solis inverter with a 5kw puredrive batt, zappi being installed on Friday.
would the 5k Puredrive battery be able to charge full in a 2 hour window.
How would i stop the battery when full from charging the car or does the charge setting in the Zappi stop this.

hope this makes sense what i'm asking as i've very little knowledge of this.
Thanks

I have a grid connected 5 kW solar system in NZ and was easily able to get an installer to arrange the software on my inverter to preferentially charge my car before feeding back power into the grid. I have a 7 kW max circuit set up for this and have had NO problems at all. Admittedly here in NZ we tend to get more sun, but over a period of 18 months I have solar powered my MG ZS EV 94% of the time. In that time I have done ~ 16,000 km. I have considered a battery for the house, but that is about #4 on my to do list. My last power bill was just over $35 (roughly 18 pounds).

 

[tjalana]

thank you crite40

 

[johnb80]

Hi,Can anyone tell me if i can charge my solar battery and electric car at same time from the grid. If i can Would I still get to charge the car at 7kw or would it reduce because house battery is charging. Have a solis inverter with a 5kw puredrive batt, zappi being installed on Friday.
would the 5k Puredrive battery be able to charge full in a 2 hour window.
How would i stop the battery when full from charging the car or does the charge setting in the Zappi stop this.

hope this makes sense what i'm asking as i've very little knowledge of this.
Thanks

The easy way to avoid any issues with battery discharge is to ask the installer to connect the ZAPPI to the supply BEFORE the CT for the solar.

 

[tjalana]

Ok, having Zappi installed on Friday, will ask him this even though I haven't a clue what it means, thank you

 

[crite40]

The easy way to avoid any issues with battery discharge is to ask the installer to connect the ZAPPI to the supply BEFORE the CT for the solar.

I have a World Solar 5 kW system on my roof here about 50 km North of Auckland NZ (lat 36° S).
This way works for me. I got the 5 kW inverter programmed to charge the car first with any surplus power. Then the spare power is fed back to the grid, should be a simple matter to feed power to the house battery after the car, but before any feedback to grid occurs. Of course it depends where you are, we get a lot more (and higher sun) here than in the UK for example. In practice I would imagine that in the UK you would have little surplus power especially outside Summer. This Southern spring
I kept my ZS EV charged, except for one overnight balancing charge, ran the house with air conditioning and had a power bill of NZ$32 (actual usage charge) for a whole month. Most solar inverters are programmable and you should get it set up for the car first I reckon because of the very high charging station rates for power in the UK. Do you have road user charges in the UK for non petrol vehicles? We EV users are going to have to pay the same rate as diesels from April 1st. About NZ$80 for every 1,000 km, roughly halve that figure to get UK pounds.

 

[johnb80]

I have a World Solar 5 kW system on my roof here about 50 km North of Auckland NZ (lat 36° S).
This way works for me. I got the 5 kW inverter programmed to charge the car first with any surplus power. Then the spare power is fed back to the grid, should be a simple matter to feed power to the house battery after the car, but before any feedback to grid occurs. Of course it depends where you are, we get a lot more (and higher sun) here than in the UK for example. In practice I would imagine that in the UK you would have little surplus power especially outside Summer. This Southern spring
I kept my ZS EV charged, except for one overnight balancing charge, ran the house with air conditioning and had a power bill of NZ$32 (actual usage charge) for a whole month. Most solar inverters are programmable and you should get it set up for the car first I reckon because of the very high charging station rates for power in the UK. Do you have road user charges in the UK for non petrol vehicles? We EV users are going to have to pay the same rate as diesels from April 1st. About NZ$80 for every 1,000 km, roughly halve that figure to get UK pounds.

The problem with battery systems follows a common routine. ZAPPI starts to charge when it sees export above a threshold, this reduces the export to near zero. The inverter then slightly increases it's output and causes a small export, ZAPPI then increases its charge rate to use the export. This repeats until it winds up to 7 kW charge, this being fed from Solar and Battery. If ZAPPI is connected to the incoming supply BEFORE the solar / battery connection the Solar / Battery system doesn't see the ZAPPI load and therefore doesn't try to feed it.

 

[crite40]

The problem with battery systems follows a common routine. ZAPPI starts to charge when it sees export above a threshold, this reduces the export to near zero. The inverter then slightly increases it's output and causes a small export, ZAPPI then increases its charge rate to use the export. This repeats until it winds up to 7 kW charge, this being fed from Solar and Battery. If ZAPPI is connected to the incoming supply BEFORE the solar / battery connection the Solar / Battery system doesn't see the ZAPPI load and therefore doesn't try to feed it.

That sounds like a problem with the inverter sensing which load it is feeding. After all the problem is quite trivial. If there is excess power over consumption in the house and the car battery needs charging, then the excess is fed to that. Once the car is fully charged that circuit is disabled and the excess power is fed to the house battery. ONLY when both are fully charged is power fed back to the grid. It looks as though the hysterisis on the inverter sensor is virtually non existent that would cause a "hunting" effect like you describe. My inverter seems to be fine because if I had an effect like this my power bills would be a LOT higher when you include charging the car directly from the mains.
BTW I presume that "ZAPPI" is you car charger system, I hadn't heard of that before. One more thing occurs to me. My car is not connected to its 7 kW type 2 cable unless it actually needs charging, then it is plugged in until either fully charged or the car needs to be used.

 

[johnb80]

That sounds like a problem with the inverter sensing which load it is feeding.

The inverter is doing exactly what it is supposed to do.

After all the problem is quite trivial. If there is excess power over consumption in the house and the car battery needs charging, then the excess is fed to that. Once the car is fully charged that circuit is disabled and the excess power is fed to the house battery. ONLY when both are fully charged is power fed back to the grid.

Yep, thats the theory, financially it's the best way at the moment.

It looks as though the hysterisis on the inverter sensor is virtually non existent that would cause a "hunting" effect like you describe.

To get the best performance with regard to grid import avoidance the deadband or hysteresis needs to be quite tight.

My inverter seems to be fine because if I had an effect like this my power bills would be a LOT higher when you include charging the car directly from the mains.

Have a google search for ZAPPI and battery systems, there's tons of it out there describing this problem and potential solutions. If you sense the grid load excluding ZAPPI to the inverter the problem is non existent, it seems sound advice on a new install to do this.

BTW I presume that "ZAPPI" is you car charger system, I hadn't heard of that before.

ZAPPI is made by MyEnergi and is one of the most widely used EVSE's

One more thing occurs to me. My car is not connected to its 7 kW type 2 cable unless it actually needs charging, then it is plugged in until either fully charged or the car needs to be used.

It makes no difference if the EVSE is wired correctly.

 

[Mike80]

Hi Tjalana, just wondered why you chose a Zappi charger when you have a Puredrive battery, when the Puredrive EV charger fully integrates with the battery. Allowing overnight charging, Green Energy (from the panels) or a mix? I've had the system for nearly a year.

 

[tjalana]

Hi Mike, not to sure what your asking as not to knowledgeable about these things. Solar Panels with a puredrive battery was installed nearly 2 years ago. Only made the decision last month to go with an Electric car. My Puredrive house battery is not a charger. As far as I've read, I can charge my Pure drive battery and car at the same time from grid.

 

[Mike80]

Hi, the Puredrive EV Charger is the equivalent of the Zappi you have had installed, comes with a separate app. but once launched you can configure whether you want to use solar/grid or combination. It was only launched a year ago, I was one of the first, but if you weren't aware of it then Puredrive have lost out on a possible sale.

 

[tjalana]

Ok, thanks, no was not aware of this, not sure if here in Ireland or not.

 

[johnb80]

Hi, the Puredrive EV Charger is the equivalent of the Zappi you have had installed, comes with a separate app. but once launched you can configure whether you want to use solar/grid or combination. It was only launched a year ago, I was one of the first, but if you weren't aware of it then Puredrive have lost out on a possible sale.

Maybe does a similar job but equivalent? - No it isnt.

 

[Ulalia]

Hi, the Puredrive EV Charger is the equivalent of the Zappi you have had installed, comes with a separate app. but once launched you can configure whether you want to use solar/grid or combination. It was only launched a year ago, I was one of the first, but if you weren't aware of it then Puredrive have lost out on a possible sale.

Hi Mike. I’ve happen to come across your post. We had a Puredrive system including EV charger fitted three months ago. The system is good except for the software to manage the EV charger which appears to be full of bugs and is unreliable. I just wondered if you’d experienced anything similar?

 

[Bam Bam]

A lot of companies seem to be expanding their offers from whichever product they started with to offer all three of:
Smart EV Charger - home battery - solar/battery inverter

Myenergy started with the Zappi and have now expanded to the Libbi.
Givenergy and Solar Edge started with solar/battery and now do an EV charger.
Hadn't heard of Puredrive but perhaps they've done the same.

I think that Zappi was the first with high-quality solar divert, but others now offer this feature - Hypervolt for instance in addition to the brands above.