EV didn’t charge properly last night. It was -4C last night. Not sure of the reason, the cold might have dropped charging rate or the load on the house might have been too high ( but shouldn’t have been through the night even with the ASHP on full blast).

Or the car into boost this morning and nothing, won’t top up. No errors but no draw indicated.

I knew range would drop in the cold but i thought it would charge.

( car in the cold due to the location of the meter, they refused to install in the garage)

19 minutes ago, Aspman said:

EV didn’t charge properly last night. It was -4C last night. Not sure of the reason, the cold might have dropped charging rate or the load on the house might have been too high ( but shouldn’t have been through the night even with the ASHP on full blast).

Or the car into boost this morning and nothing, won’t top up. No errors but no draw indicated.

I knew range would drop in the cold but i thought it would charge.

( car in the cold due to the location of the meter, they refused to install in the garage)

So it didn't charge at all?

I had it happen once with mine but it did say some kind of charging error.

And was in the middle of summer.

A simple unplug and replug in again sorted it.

I don't often charge at home (do nearly all charging at work) so I don't have much experience of home charging but I think the charging rate has slowed slightly on the work chargers this week since the colder weather.

And when they are only 16A to start with that isn't too helpful especially considering the much higher consumption in colder weather and pre-conditioning etc.

12 minutes ago, Dieselgate said:

So it didn't charge at all?

I had it happen once with mine but it did say some kind of charging error.

And was in the middle of summer.

A simple unplug and replug in again sorted it.

I don't often charge at home (do nearly all charging at work) so I don't have much experience of home charging but I think the charging rate has slowed slightly on the work chargers this week since the colder weather.

And when they are only 16A to start with that isn't too helpful especially considering the much higher consumption in colder weather and pre-conditioning etc.

No it charged about 30% of what was expected. It runs down to about 30-40% each day and we charge it to 95%. Last night it only went to 62% despite being plugged in from about 5pm. It’s on Octopus Intelligent Go so should self schedule charging to get to target by 5:30

One thing that sometimes needs doing in the cold, which i had to do 3 nights ago was go make sure the charger head is properly in tight. Plugged in when warmer or dry or wettish, then when the temp drops it is just not quite fully in enough. There will be those charging last night at minus 10 in Scotland and much colder than that around the world. Heading off to Tomintoul later if the road from the south is open. Will not need to charge there which is hit or miss at the best of times, but might need to charge someplace if i take an alternate route home. Head to Aviemore or towards Aberdeen. Tesla Superchargers.

Edited 21 November, 202521 Nov by Evolution13

@Evolution13 Good point, if the plug is not fully engaged then the contact area might be struggling to carry the full load of the recharging current and the result will be a heating up of the plug/socket and the connecting leads and terminals in the vicinity of the plug and socket. If this often happens, it will result in degradation of the contact resistance and if left unchecked could result in local charring/burning in that area, or in some cases a possible fire.

Always best to double-check that the plug is fully pushed home each time.

11 minutes ago, Aspman said:

No it charged about 30% of what was expected. It runs down to about 30-40% each day and we charge it to 95%. Last night it only went to 62% despite being plugged in from about 5pm. It’s on Octopus Intelligent Go so should self schedule charging to get to target by 5:30

I see.

That's rather odd.

Sounds like a likely case of a slow charging rate.

What fuse is your house on?

Octopus normally fit a device to prevent your charger exceeding the fuse rating. Is there any chance your ASHP + anything else that you were using might have taken you close to that?

14 minutes ago, Dieselgate said:

I see.

That's rather odd.

Sounds like a likely case of a slow charging rate.

What fuse is your house on?

Octopus normally fit a device to prevent your charger exceeding the fuse rating. Is there any chance your ASHP + anything else that you were using might have taken you close to that?

We have been through the learning of not having the plug fully engaged and not getting charging. It does need to be 100% in to work but when this has happened it’s been all or nothing not a partial charge.

We’re on a 100A fuse in the house heat pump is on an 20A (might be 32) and in theory the house could go over (we went though DSO assessment) but through the night there should be nothing but the ashp and the car (ignoring a few low power devices like TV etc on standby) even then the ashp only goes full power (for hot water) for a couple of hours.

Edited 21 November, 202521 Nov by Aspman

Do you have any individual energy monitoring devices? Or the charge point app? Or car charging history?

I've noticed IOG been tweaking their backend slot allocation algorithms. I'm getting a LOT more frequent slot re-allocations. But not had problems though charging on IOG, only problem was my home battery automations not reacting fast enough to their frequent slot updates.

I think possible reasons for partial charge:

• Charge point auto de-rating due to house load, check via energy monitor mentioned above, see if car was not drawing full 7 kW and if total house load is near 80% of your main fuse rating.

• Intelligent Octopus Go mess up, check by looking at IOG schedule, was enough slots allocated?

• Was there internet problem at any point throughout the night? Perhaps IOG slots was updated and your charge point didn't get the memo?

I've never had problem charging in the cold, I've not seen the EV itself slowing down AC charging due to UK cold weather either. This cold is nothing compared to what they get in Norway or Canada, yet they charge and drive EV's no problem. Hence I'm thinking it's something outside the EV itself.

Starting to suspect it’s the VW software. I turned the alerts back on last night and In had 15 alerts from the VW app telling me charging was complete at various times and various percentages and again didn’t meet the target charge. Wasn’t particularly cold last night either.

I’ve got charging error alerts from 3am onwards despite it working fine up till that point

Edited 22 November, 202522 Nov by Aspman

Modern cars rely on software far too much, now imagine if that app was safety critical and playing you up?

VW Group do seem to be right up there as far as the Smart Phone to BEV App issues. But then also the Connectivity issues with the latest of ICE vehicles. If everything in life was a reliable as Volkswagen Software the world war 3 would have started by now because of some computer errors.

Edited 22 November, 202522 Nov by Evolution13

Yeap, my son has a Audi A5 and it was his dream car and has so many things wrong with it, can't use his phone, sat nav, and so many other things because his phone app and the car are totally screwed up, been like it a year now it's the first week in Jan 2026 before they are able to look at it. Maybe he should stop paying the monthly lease on it?

So glad my car is not considered one of the luxury cars from VW group, I still have switches for most of my controls👍

12 hours ago, Aspman said:

Starting to suspect it’s the VW software. I turned the alerts back on last night and In had 15 alerts from the VW app telling me charging was complete at various times and various percentages and again didn’t meet the target charge. Wasn’t particularly cold last night either.

I’ve got charging error alerts from 3am onwards despite it working fine up till that point

I thought you are connected via Ohme? The car cloud API only used to tell Ohme the car's SoC.

With Octopus stopping and starting charging, those notifications are normal. I get one each time Octopus stops charging.

However charging error notification is interesting, what does it say exactly and do you get explanation of error when you open it?

Instead of dragging the car fire thread off topic, I'll reply here:

1 hour ago, lol-lol said:

Interesting angle is EU protectionism by levying Countervailing duties on Chinese EVs to help protect their own EV industry that is struggling to compete.

Indeed:

InsideEVs

The Safest Cars On Sale In Europe Now Are Chinese EVs

The Tesla Model 3 keeps its position as Europe’s safest car, but it too is made in China, and is followed by mostly Chinese cars.

"

The overall ranking still has the China-made Tesla Model 3 at the top, even though it has a lower occupant protection score of 90%, but it makes up in the other categories. The surprise second-place entrant is Nio’s Firefly, with its 96% occupant protection score, which is the highest Euro NCAP has ever recorded. It’s followed by the Tesla Model Y, the Smart #5 and BYD Seal 6.

"

9 minutes ago, wyx087 said:

Instead of dragging the car fire thread off topic, I'll reply here:

Indeed:

InsideEVs

The Safest Cars On Sale In Europe Now Are Chinese EVs

The Tesla Model 3 keeps its position as Europe’s safest car, but it too is made in China, and is followed by mostly Chinese cars.

"

The overall ranking still has the China-made Tesla Model 3 at the top, even though it has a lower occupant protection score of 90%, but it makes up in the other categories. The surprise second-place entrant is Nio’s Firefly, with its 96% occupant protection score, which is the highest Euro NCAP has ever recorded. It’s followed by the Tesla Model Y, the Smart #5 and BYD Seal 6.

"

The Chinese cars are so well appointed and safe in the main brands.

A few things I worry about like their real range ie less range buffer.

But also as the EU investigation into state subsidies and the consequential countervailing duties mean that it is that China is involved in under mining the EU and possible UK EV production to eliminate that competition.

Fortunately we have Korea doing its bit and maybe we will see Vietnam and other SE Asian countries to challenge Chinese dominance. Their historic 1 child policy can come back to bight them and India might also become more of a chalenge too.

Thank God the cold spell seems to over for a few days.

I have my Renault 5 Evolution model, 40 kwh battery nominal, 43 kwh actual, repkacing the good old Zoe which was 52 / 55 kwhs battery size.

Here in middle England where we do not get much sea temperature moderation we had -5c at night and not really above zero by day.

R5 and Mini showing 120 mile range when charged to 80 to 80% OMG.

Just charged the 60 / 65 kwh Scenic abd that is showing 165 miles at dawn.

Trip to stag do in Bournemouth is going to be a challenge as is about 130 miles cross country or 160 miles using faster motorway and charging stops not great in Dorset and Wiltshire. Challenging.

Edited 23 November, 202523 Nov by lol-lol

2020 MG5 EV 52.5 kWh (48.8 usable.) @ 100 % and minus 4*oC showing 177 miles recently and good for 165 miles. & when charging at over 95% on 50 kW CCS chargers can be charging at 20kW.... Old technology. No phone app, no useless info and easy to use controls. Even the Sat Nav surprised me how good it is. If the battery needs charged up fully then just as well to do so if needed or maybe needed to be sure to get safely to your destination or the next charger and allowing for possible diversions on wintry roads. Below not at low temps, but the charge speed can be the same when cold. 100 plus miles added in 45 minutes on a 50 kW max charger.

Edited 23 November, 202523 Nov by Evolution13

I am developing a theory that car manufacturers are lowering the point at which cars shows 100% charged.

Now they are being forced to give 8 year battery warranties where the battery must still have 70% capacity. Manufacturers will assume the worse I think where an EV is charged up to 100% every night for several years.

So those of use who only charge to 80% usually, 100% occasionally are probably being too soft on the car.

Will go for 100% on R5 during the week for a little trip to South Wales, changing to 95% i got back with only 3% abd tgat was with choosing the A road route back rather than Motorway.

Doing the 100% i will see if it adds more than 5% of related mileage and diesel a cell balancing which i understand they do. My R5 has 93 of the 3.7v L ion cell blocks, 52 kwh R5 has 186 cells but in two rows of smaller cell packs. My Urban 40 kw R5 can get 81 kw charging so not too bad a delay if I gave to splash and dash or zap and bolt i suppose. Not regretting going for tge 40 over the 52 kwh yet by the cold weather is invoking some thought.

@lol-lol that sounds like a real faff doing that stag do then, so the R5 is really a city car primarily, I could do that trip 4 times in my car.

The number of cells in your battery pack seems an odd number, @93. So that makes 93 x 3.7 = 344.10volts and at 100% SOC = 390.6volts, I would have thought it would have had 95 cells?

@lol-lol Warmer but torrential rain and AC and Demisting screen on all the time.@ 14 V here and usually 13.8-14.1 V shows & then at 14 V steady. It would pretty much do 160 miles at this state of charge. 89%. Voltage 383.

Edited 23 November, 202523 Nov by Evolution13

1 hour ago, Graham Butcher said:

@lol-lol that sounds like a real faff doing that stag do then, so the R5 is really a city car primarily, I could do that trip 4 times in my car.

The number of cells in your battery pack seems an odd number, @93. So that makes 93 x 3.7 = 344.10volts and at 100% SOC = 390.6volts, I would have thought it would have had 95 cells?

Nah because you dont want the car battery pack to be equal to the 400V charge you want it to be a good few volts less so 390 is probably a good fully charged voltage with 93 packs.

3.7v is a nominal figure. In fact you can see over 4 volts, almost 4.15 volts and the Lithium ion cells, below is for a 18650 type cell, and amazingly the pack can drop to 3.35v and still be giving power.

Nominally a car display showing State of Charge will probably show 100% charged when the cell is showing about 3.95 volts and the same call SOC display will show 0% when the voltage hits about 3.2V.

We are warned the first and last 5% or so are preferable not to be used and preferable the manufactures would like us to use the 20% to 80% range displayed, but many owners use 10% to 90% as a guide and many owners are not aware of the 5 or 6 % "buffers" or steeper parts of the curve.

Big question are all Chinese, European, Korean manufactures working with similar buffers or some less? Bjorn

https://www.youtube.com/@bjornnyland/search?query=drive%20until%20die

Bigger battery R5, 45 km past zero !!!

Well, TBH, I'd have thought that if the car states that it is a 400V system that would be the voltage when fully charged and the extra "headroom volts" would come from the actual charger, which is the normal mode of operation for most things. Take anything that you have at home, radio, calculator, etc with a rechargeable battery, it will state on the item what the normal voltage is, but then measure the voltage coming from its charger and it is higher.

I would not expect a BEV car to be any different to the normal run-of-the-mill operation.

The curve in your post looks odd to me as it suggests that the greatest capacity (mAh) is when the cell voltage is at 2.75V, which is odd as it should be when the voltage is at its maximum.

Edited 23 November, 202523 Nov by Graham Butcher

If this person has got his facts right, and the PPM is introduced as is the current thinking by almost everyone connected with the motor industry, it won't be only the BEV owners paying, it seems that everyone will be paying, even petrol and diesel cars will be paying it but at a reduced rate, in addition to the current fuel duty and then the VAT on top of that. So if it happens, we will all feel the sting.

That curve is discharge test. It is saying to get 100% out of the battery, one need to discharge from 4.15v down beyond 2.75v.

400v cars are not 400v, they vary depend on battery configuration. Just as 800v cars are typically 600 to 700v, depend on battery configuration. The "architecture" only talks about the general voltage range, the components such as air-con compressor or motor inverter will have matching voltage range to hit their performance target. The EV as an unit would be designed for pack's voltage range and quoted power would not be affected.

But outside of EV, this voltage difference do affect DC charging performance. The older Ioniq 28 kWh has faster charging than newer Ioniq 38 kWh at old current (amp) limited stations because of battery configuration resulting in higher pack voltage. It's not really something that is noticeable during every-day use though.

On 22/11/2025 at 20:39, wyx087 said:

I thought you are connected via Ohme? The car cloud API only used to tell Ohme the car's SoC.

With Octopus stopping and starting charging, those notifications are normal. I get one each time Octopus stops charging.

However charging error notification is interesting, what does it say exactly and do you get explanation of error when you open it?

Yeah so we needed a bunch of apps. the car demands an app and it has a minimal suite of charging options but they are there.
The error message is just that "there has been an error" no more information than that. As an IT person it grinds my gears when supplier hide the logs away. I could tell what was going on if I could see some logs.
We have to have an app for the charger the Ohme app.
We need to have an app for our energy supplier, Octopus.

None of the apps are by choice.

Octopus talks to the Ohme
Ohme talks to octopus and the car
The car only talks to Ohme.

Spoke with my Mrs uncle who has had an ID3 for 3yr. He said that they had had the same issues with their car and that it would on occasion no charge properly and he never got a formal answer to why. His suspicion (and he's not daft) is that the VW software is the problem, it will often 'go to sleep' and not wake up the car systems to accept charge. I got the same story from the Octopus support guy, he talked about issues with VW's not waking up to accept charge.
Uncle also suggested making sure that the charging target is the same in all places, the car has a limit that only changes in 10% increments, the charger does 5% increments. So the charger was set to 95% and the Car 100%. I've set them both to 90% now and last night it worked, nor errors.

We did see the car on Sat morning where it failed again, the charger port on the car showed a red light when I unlocked and relocked the car. This was definitely green the night before. I unplugged and replugged the car and it immediately started charging.

8 hours ago, lol-lol said:

I am developing a theory that car manufacturers are lowering the point at which cars shows 100% charged.

Now they are being forced to give 8 year battery warranties where the battery must still have 70% capacity. Manufacturers will assume the worse I think where an EV is charged up to 100% every night for several years.

So those of use who only charge to 80% usually, 100% occasionally are probably being too soft on the car.

Will go for 100% on R5 during the week for a little trip to South Wales, changing to 95% i got back with only 3% abd tgat was with choosing the A road route back rather than Motorway.

Doing the 100% i will see if it adds more than 5% of related mileage and diesel a cell balancing which i understand they do. My R5 has 93 of the 3.7v L ion cell blocks, 52 kwh R5 has 186 cells but in two rows of smaller cell packs. My Urban 40 kw R5 can get 81 kw charging so not too bad a delay if I gave to splash and dash or zap and bolt i suppose. Not regretting going for tge 40 over the 52 kwh yet by the cold weather is invoking some thought.

We've done a little research and apparently 100% on VWs is actually only 94%. Was an unoffical source.
But I do think it's a bit out of order to say that a car does say 200 miles on a charge but then very forcefully set the car to only charge to 80% to 'preserve the battery'.
Really the range should be on the 'recommended charge level'. We certailly didn;t pick the car based on 80% of it's max range nor did anyone at any point suggest that we would only get 80% or would damage the car..