Off Grid Solar EV charging

All things related to vehicles - EVs, transport, fuels
Moxi
Posts: 2329
Joined: Sun Oct 31, 2021 3:46 pm

Off Grid Solar EV charging

#1

Post by Moxi »

Whats available for off grid solar EV charging ? Can you charge DC or do you have to faff with converting to AC, I have had a bit of a google search but I am still new to EV's and might not be searching the right terms.

Yes I know it will be slower than the alternates AC systems available but I am being quoted £3.5k to get a supply from the house across the road to the drive so why not spend that money instead on a solar car charger or DIY system ?

I know that even I could loft some ground mount panels, go through an inverter to AC then connect an AC charger but that will have some losses so is there a DC equivalent that I am missing out on ?

Moxi
NikoV6
Posts: 218
Joined: Thu Aug 11, 2022 6:42 am

Re: Off Grid Solar EV charging

#2

Post by NikoV6 »

Like this?

14Kw Mitsubishi Ecodan ASHP
22 x JA Solar 455W Mono Perc Half Cell Silvers
Solis 8.0Kw 5G Dual MPPT Inverter
13.5Kw Tesla Powerwall
Zappi 2 Charger
iBoost
Caesium
Posts: 218
Joined: Mon Sep 06, 2021 9:01 pm
Location: Brighton

Re: Off Grid Solar EV charging

#3

Post by Caesium »

I think the problem is you'd have to match the DC voltage of the car's battery right? And that can be anything up to 800V on the newer platforms. Probably not something you'd want to be messing with.

On the whole my view is DIYing an EV charger is probably not the best idea. I'm mostly fine with the idea of electrocuting myself in my own house but a car that's standing outside on rubber wheels in the rain on a driveway right next to a public footpath is a different story. If I make that car live and kill someone, doesn't even bear thinking about.

For now as I've only a PHEV I make do with the relatively slow charge rates of a granny charger. I do have one of these: https://www.amazon.co.uk/gp/product/B0B ... UTF8&psc=1 - which I'm planning to stick on the end of a 32A commando socket at some point, then that'll give me faster charging and scale up to a full BEV quite nicely at some point. But even then there's grounding implications to consider I guess, which I haven't really thought about yet. If its on an RCD in the house I guess thats good enough..?
openspaceman
Posts: 662
Joined: Mon Mar 21, 2022 7:37 pm

Re: Off Grid Solar EV charging

#4

Post by openspaceman »

Caesium wrote: Tue May 23, 2023 11:10 am I think the problem is you'd have to match the DC voltage of the car's battery right? And that can be anything up to 800V on the newer platforms. Probably not something you'd want to be messing with.

On the whole my view is DIYing an EV charger is probably not the best idea. I'm mostly fine with the idea of electrocuting myself in my own house but a car that's standing outside on rubber wheels in the rain on a driveway right next to a public footpath is a different story. If I make that car live and kill someone, doesn't even bear thinking about.

For now as I've only a PHEV I make do with the relatively slow charge rates of a granny charger. I do have one of these: https://www.amazon.co.uk/gp/product/B0B ... UTF8&psc=1 - which I'm planning to stick on the end of a 32A commando socket at some point, then that'll give me faster charging and scale up to a full BEV quite nicely at some point. But even then there's grounding implications to consider I guess, which I haven't really thought about yet. If its on an RCD in the house I guess thats good enough..?

Do you need any permissions to use one of these, in fact are they legal to use in UK?
Morso S11
FIT
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Solarmax 4200S inverter
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Moxi
Posts: 2329
Joined: Sun Oct 31, 2021 3:46 pm

Re: Off Grid Solar EV charging

#5

Post by Moxi »

So it does look like its got to be the DC to AC route - that's ok I just didn't want to miss something "obvious" and I certainly don't want to be DIY up at 800V DC that feels like a Darwin award scenario - I had the flutters wiring in the 48V home stack and feel much happier at 24V and 12V DC systems in general.

Thanks

Moxi
smegal
Posts: 295
Joined: Fri Apr 08, 2022 7:51 pm

Re: Off Grid Solar EV charging

#6

Post by smegal »

openspaceman wrote: Tue May 23, 2023 11:50 am
Caesium wrote: Tue May 23, 2023 11:10 am I think the problem is you'd have to match the DC voltage of the car's battery right? And that can be anything up to 800V on the newer platforms. Probably not something you'd want to be messing with.

On the whole my view is DIYing an EV charger is probably not the best idea. I'm mostly fine with the idea of electrocuting myself in my own house but a car that's standing outside on rubber wheels in the rain on a driveway right next to a public footpath is a different story. If I make that car live and kill someone, doesn't even bear thinking about.

For now as I've only a PHEV I make do with the relatively slow charge rates of a granny charger. I do have one of these: https://www.amazon.co.uk/gp/product/B0B ... UTF8&psc=1 - which I'm planning to stick on the end of a 32A commando socket at some point, then that'll give me faster charging and scale up to a full BEV quite nicely at some point. But even then there's grounding implications to consider I guess, which I haven't really thought about yet. If its on an RCD in the house I guess thats good enough..?

Do you need any permissions to use one of these, in fact are they legal to use in UK?
It doesn't look like it'd comply with the post July 2022 regs for EV chargers to be smart.
Caesium
Posts: 218
Joined: Mon Sep 06, 2021 9:01 pm
Location: Brighton

Re: Off Grid Solar EV charging

#7

Post by Caesium »

smegal wrote: Tue May 23, 2023 12:23 pm
openspaceman wrote: Tue May 23, 2023 11:50 am Do you need any permissions to use one of these, in fact are they legal to use in UK?
It doesn't look like it'd comply with the post July 2022 regs for EV chargers to be smart.
No it doesn't have any smarts. It's not much different from every granny charger though (bit more powerful), and they're surely still sold today with every new EV? And they're surely all still legal?

I've not looked at the regs around this in detail but I wonder if it only applies to permanent installations or something, thus exempting granny chargers and ones you can stick on a commando socket like this (intended for caravan campsites and such I imagine).
Caesium
Posts: 218
Joined: Mon Sep 06, 2021 9:01 pm
Location: Brighton

Re: Off Grid Solar EV charging

#8

Post by Caesium »

So I guess its these regs: https://www.gov.uk/guidance/regulations ... rge-points

I don't see anything there about permanent installs but the entire thing seems vague and ambiguous, how unsurprising. In particular (cut out the relevant parts):
The regulations cover:
[...]
smart cables (defined as an electrical cable which is a charge point and is able to send and receive information)


The regulations do not apply to private charge points which are:
[...]
non-smart cables or rapid charge points
[...]
So the one I linked is basically a charging cable I guess? But since it's non-smart, the regulations don't apply to it?
openspaceman
Posts: 662
Joined: Mon Mar 21, 2022 7:37 pm

Re: Off Grid Solar EV charging

#9

Post by openspaceman »

Caesium wrote: Tue May 23, 2023 11:10 am I do have one of these: https://www.amazon.co.uk/gp/product/B0B ... UTF8&psc=1 - which I'm planning to stick on the end of a 32A commando socket at some point, then that'll give me faster charging and scale up to a full BEV quite nicely at some point. But even then there's grounding implications to consider I guess, which I haven't really thought about yet. If its on an RCD in the house I guess thats good enough..?

Hurry up and try it, I'm gagging to learn how it works out :) .
Morso S11
FIT
16 Sharp PV panels facing WSW 4kW
Solarmax 4200S inverter
Non FIT
3 Canadian solar DC coupled 1.75kW facing SSE
Storage
Growatt SPA3000TL BL inverter ac coupled
Growatt GBLI6532 6.5kWh lithium phosphate battery
Moxi
Posts: 2329
Joined: Sun Oct 31, 2021 3:46 pm

Re: Off Grid Solar EV charging

#10

Post by Moxi »

Doesn't need to be regulation compliant if its not hooked up to the Grid which would be the case with my proposed installation. The smart charging requirement was to allow grid stabilisation so the smart chargers can be switched on/ off if required by the NG in times of adversity. That was my understanding in any event.

Moxi
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