Solar charging

[Alex1985]

I have been looking at ways of charging my EV when the sun shines on my solar panels, I checked out Zappi etc and was quite supprised at the price of £800+

So I installed an adjustable current monitering device that switches on a contactor when the solar panels reach 2.2kw output (4kw fitted) at that point it turns off the 1.5 kw immersion heater which is also current controlled and energises a dedicated socket which the granny lead is plugged into.

I used to be running about switching the granny lead on and off when clouds came and now it is completely automatic.

I reckon I will get 40 to 50 free mIles today and I have now got (or will have on Tuesday) a 61kw home battery.

All done for about £25 plus a bit of cable and socket, a fraction of the price of a Zappi et al.

Very happy chappy

 

[Ayoull]

You may find that the MG4 won't initiate the charge, as it doesn't expect the handshake to connect and disconnect without the CP and PP pins disconnecting, EVSEs that support solar maintain an active handshake even when not charging they just advise the car that it's basically awaiting an active schedule.

Or a couple actually report a 0A output which isn't the ideal solution under the EVSE communication standards

 

[PoinDexter]

I have been looking at ways of charging my EV when the sun shines on my solar panels, I checked out Zappi etc and was quite supprised at the price of £800+

So I installed an adjustable current monitering device that switches on a contactor when the solar panels reach 2.2kw output (4kw fitted) at that point it turns off the 1.5 kw immersion heater which is also current controlled and energises a dedicated socket which the granny lead is plugged into.

I used to be running about switching the granny lead on and off when clouds came and now it is completely automatic.

I reckon I will get 40 to 50 free mIles today and I have now got (or will have on Tuesday) a 61kw home battery.

All done for about £25 plus a bit of cable and socket, a fraction of the price of a Zappi et al.

Very happy chappy

Sounds very interesting I’ve just had solar panels installed myself. I’d be interested to know what you used and how it’s is wired in. Thanks

 

[docbog]

You may find that the MG4 won't initiate the charge, as it doesn't expect the handshake to connect and disconnect without the CP and PP pins disconnecting, EVSEs that support solar maintain an active handshake even when not charging they just advise the car that it's basically awaiting an active schedule.

Or a couple actually report a 0A output which isn't the ideal solution under the EVSE communication standards

Are you saying that if you have solar you would not be able to charge? I am having lots of trouble charging mine with a pod point charger, but it did seem to work through a domestic plug (although this ignored the 80% max charge setting). I also have solar panels and not sure if this is therefore affecting things. I am even paying for a new charger to be installed but getting worried I am throwing money at it and it will not be solved. Many thanks for any advice (as it sounds like you have experience!).

 

[Ayoull]

Are you saying that if you have solar you would not be able to charge? I am having lots of trouble charging mine with a pod point charger, but it did seem to work through a domestic plug (although this ignored the 80% max charge setting). I also have solar panels and not sure if this is therefore affecting things. I am even paying for a new charger to be installed but getting worried I am throwing money at it and it will not be solved. Many thanks for any advice (as it sounds like you have experience!).

No if you have a solar capable charger it should work, but the DIY system proposed by the author of the thread shouldn't due to EVSE charging safety interlocks in place, such as expecting the plug to be removed from the cars type2 socket and reinserted before recommencing a handshake.

 

[docbog]

@Ayoull ah great. Many thanks!

 

[DelBoy]

Hi I have a zappi and solar panels. Nothing more smug than drive solely off solar. Did a long run (240 miles mostly motorway getting approx 3kwh/mile [distance chargers - expensive]) a few days ago, got back with 34 miles in reserve, left for a day then up to 100 miles just off solar which you can set off the zappi, currently after another run around town 122 miles and just starting to charge again, exported 4.1 ppkwh, works out at 1.25 ppm

 

[FiferMG4]

Hi I have a zappi and solar panels. Nothing more smug than drive solely off solar. Did a long run (240 miles mostly motorway getting approx 3kwh/mile [distance chargers - expensive]) a few days ago, got back with 34 miles in reserve, left for a day then up to 100 miles just off solar which you can set off the zappi, currently after another run around town 122 miles and just starting to charge again, exported 4.1 ppkwh, works out at 1.25 ppm

Out of interest DelBoy, which mode do you find best to have the Zappi in for charging your car from your solar panels? Is Eco mode or Eco + mode the way to go? I have a Zappi and will be having solar panels installed soon, so I’m interested to know more about this.

 

[Yandards]

@FiferMG4 the Zappis Eco+ mode has a % green slider so you can dictate how much is grid versus solar supply. Depending on your electricity tariff there will be a cost point that limits the benefit from the PV charge - it you are on a fixed tariff any PV will obviously be cheaper. In contrast a time of day tariff like Octopus Go at 12p cheap rate versus 44p peak the PV will be more expensive than the cheap rate with eco+ below 82% for example.
You've also got to consider background household load, boiling a kettle generally pulls about 3.5kw so if the Zappi is in eco+ at 100% with 4kw of PV generation it'll stop the charge - you can set a delay timer on the Zappi to prevent this however.

Another faff factor is a home battery and how that's configured - you run the risk of emptying a far smaller home battery into the car.

 

[Diggsy]

Eco+ is the way to charge purely by solar, or as close to 100% green as possible, dependant on where you set the ‘leaf’ slider.

Set at 100% it needs the full 1.4kw excess solar to start the charge, but if you set it less than 100%, it’ll take the remainder from the grid.

Edit - I see a much more detailed explanation above ^

 

[DelBoy]

Eco+, so I go to 90% on the leaf charge (sot sure what it is called) so the grid will help a little if it falls below 1.4kw, also allows the system to start charging earlier and later from solar and a little help if other things are being used (Basically any solar above 1.2kw will charge the car, higher % will lower that but at the cost of the grid). It works out as cheaper than the cheap rate at night (12p/kwh - Octopus).

@FiferMG4 the Zappis Eco+ mode has a % green slider so you can dictate how much is grid versus solar supply. Depending on your electricity tariff there will be a cost point that limits the benefit from the PV charge - it you are on a fixed tariff any PV will obviously be cheaper. In contrast a time of day tariff like Octopus Go at 12p cheap rate versus 44p peak the PV will be more expensive than the cheap rate with eco+ below 82% for example.
You've also got to consider background household load, boiling a kettle generally pulls about 3.5kw so if the Zappi is in eco+ at 100% with 4kw of PV generation it'll stop the charge - you can set a delay timer on the Zappi to prevent this however.

Another faff factor is a home battery and how that's configured - you run the risk of emptying a far smaller home battery into the car.

Great stuff here, but can you tell me how to do the delay timer setting please?

 

[jon0881]

Im a beta tester for the Ohme solar firmware so they will also come with it very soon.

Paired with the Ohme benefits with octopus agile and intelligent it’d be my top pick.

 

[FiferMG4]

Thanks guys! That’s really useful advice. @Yandards Yeah, I’m going to have to figure out how to prevent a drain on the home battery when I have that plus the solar installed. I’d rather the house use that power than the car.
Here’s one video I’ve come across which can help us:

 

[Diggsy]

Eco+, so I go to 90% on the leaf charge (sot sure what it is called) so the grid will help a little if it falls below 1.4kw, also allows the system to start charging earlier and later from solar and a little help if other things are being used (Basically any solar above 1.2kw will charge the car, higher % will lower that but at the cost of the grid). It works out as cheaper than the cheap rate at night (12p/kwh - Octopus).


Great stuff here, but can you tell me how to do the delay timer setting please?

The ‘leaf’ is Minimum Green Level - set at 100% means it has to be all green energy

 

[Diggsy]

Thanks guys! That’s really useful advice. @Yandards Yeah, I’m going to have to figure out how to prevent a drain on the home battery when I have that plus the solar installed. I’d rather the house use that power than the car.
Here’s one video I’ve come across which can help us:

The Zappi has a setting to avoid battery drain. It’s 15.2 in the following manual…

https://www.myenergi.com/wp-content/uploads/2022/07/zappi-v2.1-User-Manual-Rev-2.1.9-Dec-2022-1.pdf

 

[Ayoull]

The Zappi has a setting to avoid battery drain. It’s 15.2 in the following manual…

https://www.myenergi.com/wp-content/uploads/2022/07/zappi-v2.1-User-Manual-Rev-2.1.9-Dec-2022-1.pdf

So only works with an AC coupled battery, not a hybrid or DC coupled system, which is what most battery systems are that are installed at the same time as PV

 

[Diggsy]

So only works with an AC coupled battery, not a hybrid or DC coupled system, which is what most battery systems are that are installed at the same time as PV

Yep, seems that way. This post on their forums might help with regards DC batteries being drained…

myenergi-DC-Coupled Battery Drain, Hybrid Inverter and Zappi Charging Solution!

Hi there! I wanted to write up the solution in place with my set up. This may not be possible for everyone, but it's working for me and my needs! At t

myenergi.info

 

[FiferMG4]

The Zappi has a setting to avoid battery drain. It’s 15.2 in the following manual…

https://www.myenergi.com/wp-content/uploads/2022/07/zappi-v2.1-User-Manual-Rev-2.1.9-Dec-2022-1.pdf

Thanks Diggsy. I’ve saved that manual to my iPad. I’m not sure what sort of system the Giv-Bat 9.5 is, I’m getting installed.

 

[Diggsy]

Thanks Diggsy. I’ve saved that manual to my iPad. I’m not sure what sort of system the Giv-Bat 9.5 is, I’m getting installed.

No worries. In the link I posted above, it mentions the battery you’re getting in the thread.

 

[Ayoull]

Thanks Diggsy. I’ve saved that manual to my iPad. I’m not sure what sort of system the Giv-Bat 9.5 is, I’m getting installed.

It'll depend on if you're adding it to an existing PV system, and if you are if your current pv system is a Gen2 givenergy inverter.

As the Giv9.5 needs a givenergy Gen2 inverter