16A Phantom Battery Charge Back!?

[mrkwats]

Always have my car on Scheduled Charge at 23:00 each night, battery limit set to 90%.

Parked it in the garage last night and plugged it in (BP Chargemaster 7kW).

Just gone to car this morning, and looking at the app, it took twice as long to charge last night. So jumped in car increased limit to 95% and started the charge, it’s only on 16/16A, normally it’s on 30A!

I’ve rebooted the car and also reset my BP Chargemaster, and then turned off Scheduled Charging (in car screen). Plugged car in and now it’s charging at the full 7kW (30A).

I wonder whether the Phantom Charging bug is back quite a few of us had last year?

My car is on 2020.48.35.5

 

[Gatsojon]

I charged up at 32 amp fine last night. Zappi 2, 2020.48.5, scheduled for a 12:30 start.

 

[ACarneiro]

If it’s showing 16/16 it means the charger is only offering 16A, which is not the behaviour we saw with the charging bug months ago.

 

[Glan gluaisne]

As above, looks like the charge point is only advertising that 16 A maximum is available, or possibly that the charger(s) are wrongly interpreting that the charge point only has 16 A available. The odd thing is that it's 16 A, as that means it would need to be a control pilot signal issue if the charge point is the cause, not a proximity pilot resistance problem, as that doesn't have a 16 A option. The common values in the car connector end of the cable are 220 ohms for 32 A, 680 ohms for 20 A and 1,500 ohms for 13 A, there's no 16 A option. Some charge points have got selectable maximum current settings internally, often using DIP switches. Not sure about the Chargemaster, as I've never had the lid off one, but if it does have a selector internally there's a possibility that it wasn't properly set at installation, and has moved slightly, changing the maximum current that's being advertised to the charger(s).

 

[Glan gluaisne]

Just done some digging around, and I suspect this may have been a charge point issue, that was resolved by resetting it. The older Chargemaster has an internal jumper across two pins on the board that is only read at power up. If the jumper is in place the charge points advertises that 30/32 A is available, if the jumper is removed it advertises that 16 A is available.

The fact that the jumper is only read at power on indicates that there may have been something odd, like a spike on the supply or a brief supply dip that may have caused the charge point to re-start without properly reading the jumper. In all probability it was just a one-off, but if it does it again, and resetting the charge point clears the problem, then it could be an indication that there's something awry inside the charge point.

 

[ACarneiro]

You truly are a fountain of knowledge

 

[Glan gluaisne]

You truly are a fountain of knowledge

Not really! In this case I just did a search for the Chargemaster MIs, and found the info about the current setting jumper. Lots of charge points, including the TWC, have some sort of DIP switch/rotary switch/jumper link for setting the maximum charge current, and it turns out that the Chargemaster is one of them. It also seems that reverting to 16 A is a known fault condition, that others have experienced and that can be resolved sometimes by resetting the charge point.

 

[mrkwats]

Not really! In this case I just did a search for the Chargemaster MIs, and found the info about the current setting jumper. Lots of charge points, including the TWC, have some sort of DIP switch/rotary switch/jumper link for setting the maximum charge current, and it turns out that the Chargemaster is one of them. It also seems that reverting to 16 A is a known fault condition, that others have experienced and that can be resolved sometimes by resetting the charge point.

Brilliant, thank you very much, really insightful!!! When the chargepoint was installed there’s a separate button/toggle switch (now hidden in a junction box) which toggles between 16 and 30A. The engineer forgot to set this properly as I did a quick test whilst he was onsite and the car only charged 16A. He then quickly opened the junction box, pressed the toggle button, and the car charged at 30A, and has being do so for the last 10 months.

Hoping this is an isolated case and will keep an eye on it. Thanks, Mark.

 

[Glan gluaisne]

The switch perhaps just connects to the jumper link inside the unit, and it could be that it's the switch itself that might be the cause of the problem. If it happens again, it might be worth isolating the power, opening the junction box up and toggling the switch a few times, in case there's some issue with switch contact resistance.

Toggling switches will often reduce the contact resistance - it's a common trick used to bring down abnormally high loop resistance measurements when testing electrical installations. Nine times out of ten a high reading can be brought back to normal by just flicking the switch a few times and plugging and unplugging the plug.

 

[26ct2143]

My leaf started charging all of a sudden at 16amp instead of 32 and it was something on the charger.
Messed with the charger (rebooted etc) and came back normal

 

[DoricJim]

Resurrecting this thread as I’m having a similar issue. Equipment:

Tesla M3 LR Dec 2021 MIC on 2022.20.6
Podpoint Solo 7kw charger
Intelligent Octopus tarrif

All has been fine with charging until today, noticed only 4 kw being drawn on smart meter display. Tesla App showing 16A/16A being drawn by the car. Rebooted car, same thing. Then turned off and on the podpoint and the same. In each case it reaches 30A for a minute or 2 then drops to 16.

Took it down to local Tesco and tested it on 7kw free podpoint charger and same behaviour.

Only thing I can think of is heat. Car and charger in direct sunlight and hot today.

Any other ideas from anyone on the forum? Will test again tonight which is my normal pattern.

 

[yessuz]

Resurrecting this thread as I’m having a similar issue. Equipment:

Tesla M3 LR Dec 2021 MIC on 2022.20.6
Podpoint Solo 7kw charger
Intelligent Octopus tarrif

All has been fine with charging until today, noticed only 4 kw being drawn on smart meter display. Tesla App showing 16A/16A being drawn by the car. Rebooted car, same thing. Then turned off and on the podpoint and the same. In each case it reaches 30A for a minute or 2 then drops to 16.

Took it down to local Tesco and tested it on 7kw free podpoint charger and same behaviour.

Only thing I can think of is heat. Car and charger in direct sunlight and hot today.

Any other ideas from anyone on the forum? Will test again tonight which is my normal pattern.

Try to ping pod point guys. They can run remote diagnostics

 

[DoricJim]

Try to ping pod point guys. They can run remote diagnostics

I did wonder that but the charge at Tesco also didn’t draw 32A so wonder if it is an issue in the car. If it doesn’t resolve tonight I will try them though. Had a dodgy breaker and they were quick to replace it so seem to be good service. Thanks

 

[ACarneiro]

This is not quite the original fault, where the car would show 16/32A (drawing only 16A out of an available 32).
In your case it seems the car is only “seeing” 16A being offered (hence the 16/16A display).
I do not know if this could be related to the heat but I find it unlikely.
Probably worth opening a ticket with Tesla as well.

 

[DoricJim]

Just put it on charge again and seems to be drawing 30A now… will keep an eye on it. Thanks

 

[MrBadger]

Voltage is important to know in these situations. As well as it (along with amps) being a function of how many kW you draw, if supply voltage drops too low then various functions will derate themselves to help preserve supply or if it thinks there is a fault that might be causing sufficient voltage drop. If your voltage was indicated as being close to 220v at ~16A, I would say a chance that it was an attempt to keep supply voltage within spec.

Fwiw podpoints at Tescos seem not to provide 32A - best I have seen is 30A but only a few sites. I think they seem to be supply limited as voltage was <220v

 

[DoricJim]

Voltage is important to know in these situations. As well as it (along with amps) being a function of how many kW you draw, if supply voltage drops too low then various functions will derate themselves to help preserve supply or if it thinks there is a fault that might be causing sufficient voltage drop. If your voltage was indicated as being close to 220v at ~16A, I would say a chance that it was an attempt to keep supply voltage within spec.

Fwiw podpoints at Tescos seem not to provide 32A - best I have seen is 30A but only a few sites. I think they seem to be supply limited as voltage was <220v

Voltage is fine, steady 232v or thereabouts. Charged fine overnight so am a bit perplexed. Maybe just a one off glitch

Podpoint only ever provide 30A for some reason, home or at Tesco.

Thanks!

 

[DoricJim]

Spoke to soon dammit! Tried a quick top up at Tesco and back to 16A. Going to update to 2020.20.8 to see if the update and reboot does anything. Urgh!

If not then a SC visit might be needed which is a PIA due to being an hour away…

Assume no one else has experienced this of late and is probably a fault with my car? Thanks

 

[Roy B]

Spoke to soon dammit! Tried a quick top up at Tesco and back to 16A.

Public charge points are often 3 phase. So 16A 3-phase would be pretty normal (11kW - the fastest AC charging the M3 can do). More than 16A is only available on single phase - 32A single phase would be 7kW.

There is a little "3" symbol when you're charging on 3 phase, but it's not very prominent (and its location is a little counterintuitive, as it's not right next to the current indication IIRC).

 

[DoricJim]

Yeah, I understand that thanks, but these are 7kw and have used them many times before and normally charge at 30a indicated; I.e. standard 2 phase. Have used 22kw before and this is not the issue here.

Wonder if one of the onboard 16a converters is dodgy and the car randomly selects 2 out of the 3 when at 7kw? That way I’d have intermittent issues like this if so. Will need to find a 22kw AC charger to test.

Edit update from Tesla: Apparently couldn’t see any hardware or software issues… sigh… good news I guess… at least it did charge normally again overnight…