Thing to try: check your mains electricity supply voltage. Not because it's the most likely cause of the problem, but because it's fairly easy to test.

With care, a multimeter will show you; easier but only does the one job, a plug-in mains socket tester (mine's an Aneng AC10 but there are others); or you may have some appliance which reports, possibly even record, the mains supply voltage. Nominally 230 volts, usually about 240 volts in Britain, and the car should tolerate 216 to 253 volts without being fussed.

If it's out of range, contact your electricity supplier. If in range, keep looking for other possible causes.

 

Thanks - will try those!

We did have the charger re-installed and the garage electrics updated in our new house about 8 weeks before it all stopped working. I don't know if that's connected in some way, but it's the only change to our set-up since we first got the car (same Ohme charger, different house), two year ago.

 

I've just tested it using a commercial Type 2 AC charger, and it seemed to work just fine for the 15 minutes or so I left it plugged in for.

Welcome to the forum. If the car charges OK on a public charger, then it kinda rules out both the car and your cable as being suspect. It's not clear what settings you might have changed to enable public on-demand charging rather than using a smart tariff or timers at home. It's not unknown for such car and tariff systems to fight each other. You could test that by deleting all car and wall charger settings that relate to tariff/timings to enable plug and go to see what happens. That may lead to some data causing you to look at the integration of Octopus and Ohme.

But also, as mentioned above, it's well worth checking your home electrics for adequate voltage as many EV's reject a charge if the voltage and/or AC 50 Hz is out of normal range. Also, there are many EVs that don't like an earthing impedance that is out of range. Sometimes, if the house is on an earth spike system, then different soil conditions in wet/dry conditions can change the impedance and many EV's refuse to charge if it detects a below-par earth signal. But even the more usual PME earth loop system can develop a fault that an EV doesn't like.

Well worth contacting the sparky who worked there a few weeks ago to check that earthing and voltage etc are in range.

But it also may be a bit of crud in your cable plugs/socket that intermittently works OK in public but needs a good clearout anyway.

 

Might geo location be an issue, the car not reporting being at home?

 

An EVSE and granny charger are both just switches, I'd suspect it's your mains supply as it charges on AC elsewhere. I think if you raise a ticket with Ohme they can check and see if it's tripped due to out of tolerance voltage, if it has you'll need to get your DNO to make an adjustment.

 

Great, thanks for this - I think you could be right. Thanks!

 

Thanks to @Hitstirrer and @Mark I I think I've got a good idea of what's gone wrong. I've contacted the electrician who initially installed the charger and put electrics in the garage, and fingers crossed he'll be able to get it sorted! Will update soon hopefully

 

Plot twist - the electrician has agreed to come out and take a look this Friday, but in the meantime, I had to drive a couple of hundred miles today, and when using a fast DC charger at the services on the way home, it charged for five minutes and then failed. Got back to the car with only five minutes of additional charge. I reconnected it and stood next to the car with it unlocked and watched it charge for 20 minutes, just enough to get me home again.

Made it back home and plugged my home charger in using the charge to max option, and it miraculously started charging for a full 90 minutes until I needed to use the car!

Doing more testing this evening, I can’t find any rhyme or reason to it. It managed a 90 minute charge earlier, only to then fail again within five minutes when I tried it an hour ago.

It’s currently charging fine using the granny cable plugged into the garage socket, so I think the garage wiring must be fine, and I’m back to the 12V battery theory. Tearing my hair out here 😂

 

Plot twist

Major twist. We can only diagnose from the data provided, and that has now changed completely. Please elaborate a bit on your mention of a 12V theory.

 

Final update (hopefully). I eventually ended up taking it into the dealership and paid for them to do a diagnostic on the car. Apparently there was a software update needed for the onboard charger and as of last night, that appears to have fixed it.

Hoping there won't be any further charging issues - thanks all for your help, it was great to be able to count various things out.