Does this EV Charging Solution Exist?

[EEVblog]

Does this product exist?
An AC EV charger (usual 7kW max job) that integrates with your solar monitoring system and knows how much spare solar capacity you have at any given moment and then regulates the car EV charge rate to only use that exess power?

I'm not even sure you can get a charger that even lets you limit the charge rate to lower than the max?

[NiHaoMike]

Solaredge makes a combined solar inverter and EV charger.

Other than that, I suppose you can take a look at an open hardware charger and customize it to accept charge current commands from the network.

[solexious]

I believe the https://openevse.com/index.html already has a "PV Divert" mode for doing this, or if not has an API to roll your own.

[bdunham7]

I'm not even sure you can get a charger that even lets you limit the charge rate to lower than the max?

OpenEVSE and Juicebox have the ability to be externally controlled for other purposes, but I don't know if they have a PV-specific mode.  I'm sure it is doable and probably easily hackable on many EVSEs because it is just a matter of modulating the duty cycle on the 1 kHz squarewave.  I got (as a promo) Juicebox-made J1772 wi-fi adapter that went between my EVSE connector and the car that allowed for this sort of control without cracking the EVSE at all, but since I had/have no use for it it went on to someone who wanted it.

[Monkeh]

It does, in fact, exist: https://myenergi.com/product/zappi/

Limitation: Minimum charging power is ~1.4kW.

[EEVblog]

It does, in fact, exist: https://myenergi.com/product/zappi/
Limitation: Minimum charging power is ~1.4kW.

Tweeps pointed that one out too. Yep, looks to do that exact job.
I'm not the only one who thought that would be an obvious idea.
Mrs EEVblog wants one here, but only wants to charge the car with excess solar where possible.

[trobbins]

Similar idea as cooling/heating the house using a controllable setpoint temperature that uses the house as a thermal store.  Some control code with say an SP PRO based system (if you also had battery or a hybrid off-grid setup) would be worthwhile but the hassle is integrating to the heater/cooler or EV charger (as they have to be able to be controllable).

[Phoenix]

Unit that EVSE sells https://evse.com.au/product/eo-mini-pro-solar/

I'm sure JETCharge also do one, you'll have to enquire with them.

[EEVblog]

Unit that EVSE sells https://evse.com.au/product/eo-mini-pro-solar/

Didn't know they did a solar version. I hate those EO units though, no display and no stop button. Complained about and showed this at the end of my recent IONIQ review video.

[geo999]

it's just a matter of adjusting the PWM signal to the car that tells it how much current it can draw.
An arduino that get's the information from the solar inverter can do the job.
if you already have a charger it can be easily modified, just hijack the CP signal and drive it from arduino according to your needs.

[langwadt]

Does this product exist?
An AC EV charger (usual 7kW max job) that integrates with your solar monitoring system and knows how much spare solar capacity you have at any given moment and then regulates the car EV charge rate to only use that exess power?

I'm not even sure you can get a charger that even lets you limit the charge rate to lower than the max?

https://en.wikipedia.org/wiki/SAE_J1772#Control_Pilot ?

[f4eru]

https://www.sma.de/en/products/e-mobility-charging-solutions/sma-ev-charger-74-22.html

[EEVblog]

Does this product exist?
An AC EV charger (usual 7kW max job) that integrates with your solar monitoring system and knows how much spare solar capacity you have at any given moment and then regulates the car EV charge rate to only use that exess power?

I'm not even sure you can get a charger that even lets you limit the charge rate to lower than the max?

https://en.wikipedia.org/wiki/SAE_J1772#Control_Pilot ?

Yes. Was aware of that. I don't know if the PWM charge rate is linearly grandular though?
i.e. Do all cars take the PWM signal and linearly adjust the max current draw, or is it just stepped?
Wouldn't surprise me if it's stepped, and/or varies between cars.

[langwadt]

Does this product exist?
An AC EV charger (usual 7kW max job) that integrates with your solar monitoring system and knows how much spare solar capacity you have at any given moment and then regulates the car EV charge rate to only use that exess power?

I'm not even sure you can get a charger that even lets you limit the charge rate to lower than the max?

https://en.wikipedia.org/wiki/SAE_J1772#Control_Pilot ?

Yes. Was aware of that. I don't know if the PWM charge rate is linearly grandular though?
i.e. Do all cars take the PWM signal and linearly adjust the max current draw, or is it just stepped?
Wouldn't surprise me if it's stepped, and/or varies between cars.

"The SAE defines the ampacity value to be derived by a formula based on the 1 ms full cycle (of the 1 kHz signal) with the maximum continuous ampere rating being 0.6 A per 10 µs up to 850µs (with the lowest 100 µs x .6 A = 6 A). Above 850µs, the formula requires subtraction of 640µs and multiplying the difference by 2.5. For example (960 µs - 640 µs) x 2.5A = 80 A."

[EEVblog]

Does this product exist?
An AC EV charger (usual 7kW max job) that integrates with your solar monitoring system and knows how much spare solar capacity you have at any given moment and then regulates the car EV charge rate to only use that exess power?

I'm not even sure you can get a charger that even lets you limit the charge rate to lower than the max?

Yes. Was aware of that. I don't know if the PWM charge rate is linearly grandular though?
i.e. Do all cars take the PWM signal and linearly adjust the max current draw, or is it just stepped?
Wouldn't surprise me if it's stepped, and/or varies between cars.

"The SAE defines the ampacity value to be derived by a formula based on the 1 ms full cycle (of the 1 kHz signal) with the maximum continuous ampere rating being 0.6 A per 10 µs up to 850µs (with the lowest 100 µs x .6 A = 6 A). Above 850µs, the formula requires subtraction of 640µs and multiplying the difference by 2.5. For example (960 µs - 640 µs) x 2.5A = 80 A."

Given that cars do actually have internal limited step charge profiles, it wouldn't surprise me if they don't implement that. As long as you don't exceed the maximum implied by the PWM, I assume that's ok.
https://en.wikipedia.org/wiki/SAE_J1772#Control_Pilot ?

[langwadt]

Does this product exist?
An AC EV charger (usual 7kW max job) that integrates with your solar monitoring system and knows how much spare solar capacity you have at any given moment and then regulates the car EV charge rate to only use that exess power?

I'm not even sure you can get a charger that even lets you limit the charge rate to lower than the max?

Yes. Was aware of that. I don't know if the PWM charge rate is linearly grandular though?
i.e. Do all cars take the PWM signal and linearly adjust the max current draw, or is it just stepped?
Wouldn't surprise me if it's stepped, and/or varies between cars.

"The SAE defines the ampacity value to be derived by a formula based on the 1 ms full cycle (of the 1 kHz signal) with the maximum continuous ampere rating being 0.6 A per 10 µs up to 850µs (with the lowest 100 µs x .6 A = 6 A). Above 850µs, the formula requires subtraction of 640µs and multiplying the difference by 2.5. For example (960 µs - 640 µs) x 2.5A = 80 A."

Given that cars do actually have internal limited step charge profiles, it wouldn't surprise me if they don't implement that. As long as you don't exceed the maximum implied by the PWM, I assume that's ok.
https://en.wikipedia.org/wiki/SAE_J1772#Control_Pilot ?

get out the signal generator and an ammeter and find out

[EEVblog]

Does this product exist?
An AC EV charger (usual 7kW max job) that integrates with your solar monitoring system and knows how much spare solar capacity you have at any given moment and then regulates the car EV charge rate to only use that exess power?

I'm not even sure you can get a charger that even lets you limit the charge rate to lower than the max?

Yes. Was aware of that. I don't know if the PWM charge rate is linearly grandular though?
i.e. Do all cars take the PWM signal and linearly adjust the max current draw, or is it just stepped?
Wouldn't surprise me if it's stepped, and/or varies between cars.

"The SAE defines the ampacity value to be derived by a formula based on the 1 ms full cycle (of the 1 kHz signal) with the maximum continuous ampere rating being 0.6 A per 10 µs up to 850µs (with the lowest 100 µs x .6 A = 6 A). Above 850µs, the formula requires subtraction of 640µs and multiplying the difference by 2.5. For example (960 µs - 640 µs) x 2.5A = 80 A."

Given that cars do actually have internal limited step charge profiles, it wouldn't surprise me if they don't implement that. As long as you don't exceed the maximum implied by the PWM, I assume that's ok.
https://en.wikipedia.org/wiki/SAE_J1772#Control_Pilot ?

get out the signal generator and an ammeter and find out

I would but I don't have a fast AC charger at home.
Will be getting one next month though, currently getting the garage upgraded and Mrs EEVblog wants one, hence this thread.

[aargee]

The latest Renew Magazine (Issue 156) has an article on EVSE (Electric Vehicle Supply Equipment), it is an interesting read.

https://renew.org.au/renew-magazine/

[DenzilPenberthy]

It's not an EV charger but this exists for hot water. 

As I under stand it: it measures the current going into or out of your house. Presumably with a clamp meter on your incoming supply. Then it PWMs your water tank immersion heater to try and adjust your power export to zero.

https://www.immersun.co.uk/

It's a very simple system to implement, I'm amazed if it doesn't exist yet for an EV charger.

[EEVblog]

It's a very simple system to implement, I'm amazed if it doesn't exist yet for an EV charger.

It does, there are several products that do it, and it's the main marketing spin for them.

[EEVblog]

Is there any (legal) issue in Oz with installing a 32A single phase outlet to power a single phase level 2 charger?
They seem to be designed for fixed installations?

[mikeselectricstuff]

Does this product exist?
An AC EV charger (usual 7kW max job) that integrates with your solar monitoring system and knows how much spare solar capacity you have at any given moment and then regulates the car EV charge rate to only use that exess power?

I'm not even sure you can get a charger that even lets you limit the charge rate to lower than the max?

https://en.wikipedia.org/wiki/SAE_J1772#Control_Pilot ?

Yes. Was aware of that. I don't know if the PWM charge rate is linearly grandular though?
i.e. Do all cars take the PWM signal and linearly adjust the max current draw, or is it just stepped?
Wouldn't surprise me if it's stepped, and/or varies between cars.

Does it actually matter? As long as the car doesn't draw more than the amount indicated by the PWM signal it will work.

[mikeselectricstuff]

Is there any (legal) issue in Oz with installing a 32A single phase outlet to power a single phase level 2 charger?
They seem to be designed for fixed installations?

I'm sure Oz electrical codes are different, but as an example in the UK, regs require that any outlet "intended to charge an EV" needs to have DC-tolerant RCD protection and PEN fault protection. (I believe the latter is a fairly UK-specific requirement) Unlike a fixed installation, you can't rely on any internal protection in the EVSE as there is no guarantee of what may be plugged into the socket.

[EEVblog]

Does this product exist?
An AC EV charger (usual 7kW max job) that integrates with your solar monitoring system and knows how much spare solar capacity you have at any given moment and then regulates the car EV charge rate to only use that exess power?

I'm not even sure you can get a charger that even lets you limit the charge rate to lower than the max?

https://en.wikipedia.org/wiki/SAE_J1772#Control_Pilot ?

Yes. Was aware of that. I don't know if the PWM charge rate is linearly grandular though?
i.e. Do all cars take the PWM signal and linearly adjust the max current draw, or is it just stepped?
Wouldn't surprise me if it's stepped, and/or varies between cars.

Does it actually matter? As long as the car doesn't draw more than the amount indicated by the PWM signal it will work.

The point was that fully adjustable charge rate is required in order to ensure that the charge rate matches your solar output minus your house consumption.
If the car is fixed level charge levels only then there is no point having the intelligent solar connection to only consume your excess solar.

[mikeselectricstuff]

Does this product exist?
An AC EV charger (usual 7kW max job) that integrates with your solar monitoring system and knows how much spare solar capacity you have at any given moment and then regulates the car EV charge rate to only use that exess power?

I'm not even sure you can get a charger that even lets you limit the charge rate to lower than the max?

https://en.wikipedia.org/wiki/SAE_J1772#Control_Pilot ?

Yes. Was aware of that. I don't know if the PWM charge rate is linearly grandular though?
i.e. Do all cars take the PWM signal and linearly adjust the max current draw, or is it just stepped?
Wouldn't surprise me if it's stepped, and/or varies between cars.

Does it actually matter? As long as the car doesn't draw more than the amount indicated by the PWM signal it will work.

The point was that fully adjustable charge rate is required in order to ensure that the charge rate matches your solar output minus your house consumption.
If the car is fixed level charge levels only then there is no point having the intelligent solar connection to only consume your excess solar.

Why not? Surely the only issue is that sometimes the car may pull a bit less.This will happen anyway as it nears a high state of charge. I can't think why a car would have significant stepping at home charge levels - it's common for rapid charging, but I suspect this is mostly about being able to easily simulate the thermal performance, which isn't an issue at 7kW