[GGi]

The last several charging sessions are taking over an hour to charge to 80% while in the past it used to take about 30-40 minutes. We have not changed any charging habits. Live in Sacramento (not freezing cold), and charging only at electrify America CCS 150 chargers. Electrify America did not find anything wrong with their chargers. They suggested to hold the charging cable straight for a few minutes as the charger is communicating with the car as the cables are liquid cooled. Tried different locations, different charging units without any improvement in charging times.
Took it to the local VW dealership with the 32% charge left. They charged it to 100% which took 2 hrs and 15 min. The dealership said routinely charging to 80% is not a good idea and should be charging to 100%. And the battery is "all fine". The change is due to the weather.
Been in touch with VW regional case manager who initially said the dealership could not reproduce the problem. I emailed her back with 1) did the dealership run tests on the battery and did she actually review the report 2) why did the dealership choose 100% instead of 80% 3) IMO they did reproduce the issue as it took 2 hrs and 15 min to charge from 32 to 100% when it should normally take just over an hour.
The response from VW regional case manager is the dealership are the ones to address my concerns.

Anyone with similar issues?
If the dealer repeats that the battery is fine and the longer charge time is due to weather how should I proceed.

Thanks for suggestions and responses.

 

[VW TECHNICIAN]

What was your SOC before starting charging?
What was Fast DC charger power at dealership.?
What was your battery temperature?
How confident are you that EA charger is putting out max speed?
There are many variables.
Do you have actual service report?
If you have one post it please.

 

[Islander]

If your VW dealership told you to routinely charge to 100%, they don't know what they're talking about. For routine charging, 80% is the limit recommended by VW

 

[agzand]

If your VW dealership told you to routinely charge to 100%, they don't know what they're talking about. For routine charging, 80% is the limit recommended by VW

Correct, charge to 80% routinely with occasional (once every couple of months) charge to 100% on a level 2 charger.

 

[Islander]

Correct, charge to 80% routinely with occasional (once every couple of months) charge to 100% on a level 2 charger.

What's the reasoning for the occasional charge to 100%? And when you do this, should you plan to drive off some of that charge right away after hitting 100%?

 

[agzand]

What's the reasoning for the occasional charge to 100%? And when you do this, should you plan to drive off some of that charge right away after hitting 100%?

It will help with cell rebalancing, and yes, I time it to leave in an hour or so after hitting 100%.

 

[Don]

How long it takes to charge is determined by the communication between the charger and the car. After 6 or 7 sessions at my local EA CCS charger, I've yet to see anything close to a 125Kw charge rate. True, I've never gone there with the battery even close to 5% as I usually recharge when it's down around 20% or so and the EA station usually says "Car is requesting 90Kw" or something to that effect at the start and then as it approaches 65 or 70% the charge rate drops further

Me, I'm tickled pink with this arrangement as I have no real desire to charge at much over 1C as I'm sure slower rates are better for the battery and I'm in no real hurry - The difference in charge time for me is only 15 or 20 minutes at most at the slower rate and I'm fine with that

Maybe I would need to be down closer to 5% to see a faster rate? Maybe the EA charger is dialing it back for some reason? Maybe my battery isn't hot/cold enough to see faster charge rates? I have no idea what communication is happening between the car and the charger, but I've never been concerned enough to even look into it because . . . . I much prefer 90Kw to 125 anyway and as I said, I'm not in a hurry

Is the OP recharging at CCS stations most of the time? Maybe the battery is programmed to protect itself from constant rapid charges by occasionally dialing back the charge speed? I have no idea. I would highly doubt the OP's battery is faulty, but what do I know?

Don

 

[Islander]

I've yet to see anything close to a 125Kw charge rate. True, I've never gone there with the battery even close to 5% as I usually recharge when it's down around 20% or so and the EA station usually says "Car is requesting 90Kw" or something to that effect at the start and then as it approaches 65 or 70% the charge rate drops further

I do almost all of my fast charging at around a 20-25% SOC, and more often than not an EA charge session starts at over 120 kW. I expect to see above 100 kW until just before I reach a 50% SOC.

 

[Don]

I do almost all of my fast charging at around a 20-25% SOC, and more often than not an EA charge session starts at over 120 kW. I expect to see above 100 kW until just before I reach a 50% SOC.

Then it must be my EA station. My car is nearly new (2,000 miles) and I've never ever seen more than 90Kw at any of my charge sessions

Edit: Looking at the EA Charge Report for my last session (which I've never bothered to do before) shows I got 28Kw in 21.5 minutes, which works out to be an average of around 80Kw, if my math is correct? 90Kw to begin and then tapering slightly at around 60 to 65%

Don

 

[agzand]

Then it must be my EA station. My car is nearly new (2,000 miles) and I've never ever seen more than 90Kw at any of my charge sessions

Edit: I guess I gotta take that back! Looking at the EA Charge report from my last session (which I've never bothered to do before) I see that I got 28Kw in 21.5 minutes and that works out to an average of . . . .around 130Kw? I'm guessing the 90Kw it shows on the screen when charging commences is just the initial connection speed?

Don

28 kW in 21.5 min is 78 kW per hour. Pretty normal charge rate for iD4.

If the car charges is slower than before it could be two things, 1) the charger has some issues due to supply or weather or whatever, or 2) this is very unlikely at 2000 miles, but the battery management system keeps a history of battery fast charging sessions, when number of fast charge sessions exceed the level that the battery can take safely it could start slowing down charging rate to protect the battery.

 

[John411iD]

Charging rate is based on temperature of the battery pack:

DCFC speed while cold?

I drive a Bolt, and one of its big limitations is DCFC speed when the pack is cold: the pack only reaches full charge speed above 75F (24C), and if the pack is 55F (13C), it charges at only about half of peak rate. Also, below freezing, the pack actually cools as you drive, even at...

www.vwidtalk.com

 

[Don]

. . . . the battery management system keeps a history of battery fast charging sessions, when number of fast charge sessions exceed the level that the battery can take safely it could start slowing down charging rate to protect the battery.

That was my earlier guess as to the OP's original problem - I didn't know for sure the car did this, but it sure makes sense. Maybe he's charging exclusively at EA CCS stations?

Don

 

[VW TECHNICIAN]

It will help with cell rebalancing, and yes, I time it to leave in an hour or so after hitting 100%.

That is not correct....passive balancing happening is irrelevant to SOC....

 

[agzand]

That is not correct....passive balancing happening is irrelevant to SOC....

Many batteries show imbalance cells after not charging to 100% for long periods. I am not sure how iD cars behave in the long run, but other EVs (e.g. Tesla, Leaf, etc.) have benefited from charging to 100% once in a while. I expect the same thing will happen with iD4.

Tesla's New Stance On Charging Habits + Elon Responds: Video

 

[d287]

How long it takes to charge is determined by the communication between the charger and the car. After 6 or 7 sessions at my local EA CCS charger, I've yet to see anything close to a 125Kw charge rate. True, I've never gone there with the battery even close to 5% as I usually recharge when it's down around 20% or so and the EA station usually says "Car is requesting 90Kw" or something to that effect at the start and then as it approaches 65 or 70% the charge rate drops further

Me, I'm tickled pink with this arrangement as I have no real desire to charge at much over 1C as I'm sure slower rates are better for the battery and I'm in no real hurry - The difference in charge time for me is only 15 or 20 minutes at most at the slower rate and I'm fine with that

Maybe I would need to be down closer to 5% to see a faster rate? Maybe the EA charger is dialing it back for some reason? Maybe my battery isn't hot/cold enough to see faster charge rates? I have no idea what communication is happening between the car and the charger, but I've never been concerned enough to even look into it because . . . . I much prefer 90Kw to 125 anyway and as I said, I'm not in a hurry

Is the OP recharging at CCS stations most of the time? Maybe the battery is programmed to protect itself from constant rapid charges by occasionally dialing back the charge speed? I have no idea. I would highly doubt the OP's battery is faulty, but what do I know?

Don

I’ve only tried EA once, but plugged in at 15% and left at 30% and it was drawing over 125k the entire time… like 126-127, so I assume the extra wattage was for battery conditionin.

 

[VW TECHNICIAN]

Many batteries show imbalance cells after not charging to 100% for long periods. I am not sure how iD cars behave in the long run, but other EVs (e.g. Tesla, Leaf, etc.) have benefited from charging to 100% once in a while. I expect the same thing will happen with iD4.

Tesla's New Stance On Charging Habits + Elon Responds: Video

Whatever you have learned searching on the internet is not how ID4 BMS operate..... passive balancing is active whenever necessary and it doesn't matter what SOC is.

 

[agzand]

Whatever you have learned searching on the internet is not how ID4 BMS operate..... passive balancing is active whenever necessary and it doesn't matter what SOC is.

Tesla has passive rebalancing too. Maybe they know something that you don't know. It has to do with BMS calibration (knowing what is 100% and what is 0%). It also sounds like common sense to me.

 

[wtatun]

Tesla has passive rebalancing too. Maybe they know something that you don't know. It has to do with BMS calibration (knowing what is 100% and what is 0%). It also sounds like common sense to me.

I’d go with the VW technician (@VW TECHNICIAN) on knowing how the VW works. 🤷‍♂️

 

[VW TECHNICIAN]

Tesla has passive rebalancing too. Maybe they know something that you don't know. It has to do with BMS calibration (knowing what is 100% and what is 0%). It also sounds like common sense to me.

If you talking about Tesla Ghost drain and BMS drift that is something Tesla specific.
0 and 100% are always known there is no need to discharge quite low or charge high to get BMS in balance.
The real million dollar question is about Tesla HV Battery packs, why they loose so much SOC when not plugged in for quite some time. Believe me i do know the answer to this.
Choice is yours whatever you want to believe...

 

[ChristophW]

We have not changed any charging habits.

This is precious little info, unfortunately. From how low SOC did you start each time? You cannot compare a charge session that started at 15% to one that started at 40%, and there are nuances in between. My advice is to first establish that you start from the same or similar level. Then make sure to change to another charger when you do not get 125 kW at under 20% SOC. Only then can you suspect that something is off with your car.