10mm spanner saves the day.

[Kithmo]

Because it was quiet at 7am, I decided to try the 15 minutes free trick before I started my shopping and confirming the charge at my local Tesco's Pod point today.
I plugged in, sat in the car and locked it, the car started charging. 15 minutes later the Pod point clicked off so I thought I would unplug, plug back in, confirm the charge and do my shopping.
I unlocked the car, unplugged then plugged it back in and locked the car but it wouldn't start the charge.
I tried unplugging both ends of the cable again, no joy.
So I thought maybe if I start again by unlocking the car put it in Ready mode and switching it off again etc.
It wouldn't let me put it in Ready mode, "HV Battery fault" warning. I tried it a couple of times, making sure foot on brake firmly etc, no joy.
10mm spanner out disconnected -ve for about a minute, reconnected and all was well (phew ?‍?)
So it appears my Gen 1 ZS doesn't like it when the power supply is interrupted whilst it's charging.
If it wasn't for this forum and the 10mm spanner advice learned on here, I'd have been stuck at Tesco's waiting for the AA.

 

[Gadget Geek]

Get yourself a quick disconnect adapter and you can forget the spanner.

 

[Lovemyev]

Because it was quiet at 7am, I decided to try the 15 minutes free trick before I started my shopping and confirming the charge at my local Tesco's Pod point today.
I plugged in, sat in the car and locked it, the car started charging. 15 minutes later the Pod point clicked off so I thought I would unplug, plug back in, confirm the charge and do my shopping.
I unlocked the car, unplugged then plugged it back in and locked the car but it wouldn't start the charge.
I tried unplugging both ends of the cable again, no joy.
So I thought maybe if I start again by unlocking the car put it in Ready mode and switching it off again etc.
It wouldn't let me put it in Ready mode, "HV Battery fault" warning. I tried it a couple of times, making sure foot on brake firmly etc, no joy.
10mm spanner out disconnected -ve for about a minute, reconnected and all was well (phew ?‍?)
So it appears my Gen 1 ZS doesn't like it when the power supply is interrupted whilst it's charging.
If it wasn't for this forum and the 10mm spanner advice learned on here, I'd have been stuck at Tesco's waiting for the AA.

I have always been of the same opinion really, why bother TBH ?.
I mean, how much free juice are you likely to pull in fifteen short minutes?.
It would be lucky to get you off the car park with what you have gained.
Had you not done the old 10mm spanner ? trick, you could have been stuck there for hours waiting for the AA.
Really not worth the bother IMHO ?.

 

[daverobbo]

Get yourself a quick disconnect adapter and you can forget the spanner.

Just being lazy, do you have a link to the disconnect adapter?

 

[Gadget Geek]

I have always been of the same opinion really, why bother TBH ?.
I mean, how much free juice are you likely to pull in fifteen short minutes?.
It would be lucky to get you off the car park with what you have gained.
Had you not done the old 10mm spanner ? trick, you could have been stuck there for hours waiting for the AA.
Really not worth the bother IMHO ?.

I've sat there whilst her indoors did some shopping. 1 mile gained every 2 minutes . . . I'll let you do the maths.

Just being lazy, do you have a link to the disconnect adapter?

This is the one I fitted.
Amazon product ASIN B07TQ7ZK9P
This is it fitted.

 

[Kithmo]

I have always been of the same opinion really, why bother TBH ?.
I mean, how much free juice are you likely to pull in fifteen short minutes?.
It would be lucky to get you off the car park with what you have gained.
Had you not done the old 10mm spanner ? trick, you could have been stuck there for hours waiting for the AA.
Really not worth the bother IMHO ?.

I certainly won't be doing it again. ?
FWIW, 15 minutes worth would cover my journey to Tesco's and back home but it was really just a trial to see what happens and I found out to my detriment.
I know this was on the 7kW charger, but what's worrying though is, if I hook up to one of those rapids that cuts off at 80% would it do the same ?
As a bonus though, I found the -ve battery connector and the post were heavily oxidised, so I took the chance to clean up both the +ve and -ve posts and connectors when I got home, hopefully preventing further battery problems down the line.

 

[daverobbo]

I've sat there whilst her indoors did some shopping. 1 mile gained every 2 minutes . . . I'll let you do the maths.


This is the one I fitted.
Amazon product ASIN B07TQ7ZK9P
This is it fitted.

How does this work?

 

[N2STY]

How does this work?

 

[daverobbo]

thanks

 

[N2STY]

Got to love Amazon someone posts a link for something price £3 ish after a few buy they up the price over double

 

[Tim Green]

The problem of supply disconnecting may well not happen on other charge points. I would suggest that the one used by Kithmo happened to have a very "noisy" contactor and these can produce huge transient "spikes" during connection or disconnection. There will be a filter to limit these on the input of the ZS but it seems not adequate in this case. 10mm spanner is the answer, similar to the old PC "turn it off and on again".

 

[Kithmo]

The problem of supply disconnecting may well not happen on other charge points. I would suggest that the one used by Kithmo happened to have a very "noisy" contactor and these can produce huge transient "spikes" during connection or disconnection. There will be a filter to limit these on the input of the ZS but it seems not adequate in this case. 10mm spanner is the answer, similar to the old PC "turn it off and on again".

It needs a CTRL-ALT-DELETE button on the dash to reset the ECUs.

 

[Tim Green]

Good idea. A nice big red button- not software!

 

[AK OK]

The problem of supply disconnecting may well not happen on other charge points. I would suggest that the one used by Kithmo happened to have a very "noisy" contactor and these can produce huge transient "spikes" during connection or disconnection. There will be a filter to limit these on the input of the ZS but it seems not adequate in this case. 10mm spanner is the answer, similar to the old PC "turn it off and on again".

Where's that "spike" theory from?

 

[Coulomb]

Where's that "spike" theory from?

Possibly from someone like me, rabbiting on about how the input to the on-board charger is a boost converter, which has a large inductor in series with the AC-input.

So it depends on how the Tesco "charger" terminates the charge. If they do it right, they kill the control pilot signal, which tells the car to stop using power electronically (power ramps down to zero over a few mains cycles). If they do it wrong, they simply open the contactor, interrupting the flow of AC to the on-board charger. If the inductor current happened to be near its peak at that time, when the AC input is interrupted, the energy in the inductor has nowhere to go. Inductors really want to keep the current flowing; put another way, the voltage across the inductor is proportional to the rate of change of the current. Interrupting the current completely by opening the contactor under load means a very high (near infinite) rate of change of current. That means that the inductor produces a very high (many kilo-volt) voltage across it, so as the contactor is opening, this high voltage bridges the now-opening contacts, and finds a path to keep the current going. Unfortunately, switch S (a semiconductor) is the shortest path, and the semiconductor is typically rated at around 600-1200 V. So it could easily be damaged. To prevent this, there are protection components (not shown above), but those have a hard life if they see repeated spikes, and so they can burn out over time, effectively leaving the expensive semiconductor unprotected.

There are voltage sensors sensing the input voltage; this is necessary to present a nice high-power factor load to the grid. I'm guessing that spikes cause very high values to be measured here, which causes the on-board charger firmware to freak out and attempt to protect itself. Removing the 12 V for a minute or so allows it to forget that protection and go back to normal.

DC chargers have way more of a to-and-fro communication with one of the car's computers, so I would expect the "stop charging at 80%" to be far smoother than terminating an AC charge. Also, all the power conversion is in the DC charger; the car's on-board charger doesn't do any power conversion when DC charging. So the DC charger is in control all the time, and can ramp the power down to zero cleanly.

 

[Lovemyev]

Possibly from someone like me, rabbiting on about how the input to the on-board charger is a boost converter, which has a large inductor in series with the AC-input.

So it depends on how the Tesco "charger" terminates the charge. If they do it right, they kill the control pilot signal, which tells the car to stop using power electronically (power ramps down to zero over a few mains cycles). If they do it wrong, they simply open the contactor, interrupting the flow of AC to the on-board charger. If the inductor current happened to be near its peak at that time, when the AC input is interrupted, the energy in the inductor has nowhere to go. Inductors really want to keep the current flowing; put another way, the voltage across the inductor is proportional to the rate of change of the current. Interrupting the current completely by opening the contactor under load means a very high (near infinite) rate of change of current. That means that the inductor produces a very high (many kilo-volt) voltage across it, so as the contactor is opening, this high voltage bridges the now-opening contacts, and finds a path to keep the current going. Unfortunately, switch S (a semiconductor) is the shortest path, and the semiconductor is typically rated at around 600-1200 V. So it could easily be damaged. To prevent this, there are protection components (not shown above), but those have a hard life if they see repeated spikes, and so they can burn out over time, effectively leaving the expensive semiconductor unprotected.

There are voltage sensors sensing the input voltage; this is necessary to present a nice high-power factor load to the grid. I'm guessing that spikes cause very high values to be measured here, which causes the on-board charger firmware to freak out and attempt to protect itself. Removing the 12 V for a minute or so allows it to forget that protection and go back to normal.

DC chargers have way more of a to-and-fro communication with one of the car's computers, so I would expect the "stop charging at 80%" to be far smoother than terminating an AC charge. Also, all the power conversion is in the DC charger; the car's on-board charger doesn't do any power conversion when DC charging. So the DC charger is in control all the time, and can ramp the power down to zero cleanly.

Thank you ?.
An extremely informative post and thank you for taking the time to compile this reply.
Sharing is caring ! ?.

 

[Gadget Geek]

Possibly from someone like me, rabbiting on about how the input to the on-board charger is a boost converter, which has a large inductor in series with the AC-input.

So it depends on how the Tesco "charger" terminates the charge. If they do it right, they kill the control pilot signal, which tells the car to stop using power electronically (power ramps down to zero over a few mains cycles). If they do it wrong, they simply open the contactor, interrupting the flow of AC to the on-board charger. If the inductor current happened to be near its peak at that time, when the AC input is interrupted, the energy in the inductor has nowhere to go. Inductors really want to keep the current flowing; put another way, the voltage across the inductor is proportional to the rate of change of the current. Interrupting the current completely by opening the contactor under load means a very high (near infinite) rate of change of current. That means that the inductor produces a very high (many kilo-volt) voltage across it, so as the contactor is opening, this high voltage bridges the now-opening contacts, and finds a path to keep the current going. Unfortunately, switch S (a semiconductor) is the shortest path, and the semiconductor is typically rated at around 600-1200 V. So it could easily be damaged. To prevent this, there are protection components (not shown above), but those have a hard life if they see repeated spikes, and so they can burn out over time, effectively leaving the expensive semiconductor unprotected.

There are voltage sensors sensing the input voltage; this is necessary to present a nice high-power factor load to the grid. I'm guessing that spikes cause very high values to be measured here, which causes the on-board charger firmware to freak out and attempt to protect itself. Removing the 12 V for a minute or so allows it to forget that protection and go back to normal.

DC chargers have way more of a to-and-fro communication with one of the car's computers, so I would expect the "stop charging at 80%" to be far smoother than terminating an AC charge. Also, all the power conversion is in the DC charger; the car's on-board charger doesn't do any power conversion when DC charging. So the DC charger is in control all the time, and can ramp the power down to zero cleanly.

That takes me back to my City and Guilds Electronic Servicing course. Also a good explanation why you shouldn't turn the granny charger off at the plug until the car has terminated the charging session.

 

[Tim Green]

It's probably better to never stop any AC charge before completion for the reasons noted above. Thank you Coulomb for taking me back 50 years to head scratching days in the lecture theatre and labs! I had thought my use of "filter" would be enough for most people!

 

[AK OK]

It's probably better to never stop any AC charge before completion for the reasons noted above. Thank you Coulomb for taking me back 50 years to head scratching days in the lecture theatre and labs! I had thought my use of "filter" would be enough for most people!

Just unlock the car wait ½ sec for the bzzt, pull the plug out simples ??‍

 

[Tim Green]

Its stopping the charge from the other end I had in mind.