Battery losing autonomy

[MarieMartin]

Hi !
I have a newly purchased 2019 eGolf since may 27th. For the last six days, we have noticed a significant drop in our car autonomy, and dropping more and more everyday.

The first five days, we had an autonomy displayed of 180-190 km with an approximately 90% charged battery. Then, we charged the car with the default charger coming with the car. When fully charged, the displayed autonomy was then 180km. We used it a bit, plugged it back. The next day, it was now 150 km still with a fully charged battery. Monday, 133 km, tuesday it was 112 km and yesterday 88 km !
Since monday, we are now charging with our home charging station but that hasn’t improved the result.
Plus the battery can’t keep its charge. Overnight, while not being plugged, it went from 79 to 56 km of autonomy.

I went back to our dealership, at first the service advisor was telling us that the autonomy reflected our style of driving, but I have looked at our Think Blue Monitor and we have an approximative 82-85 score of efficiency and have a mean consumption of 13-16 kwh/100km which would assure us of at least 200 km autonomy with our 35,8 kwh battery. Then, the service manager didn’t know what to tell us so he’ll have an engineer of VW Canada look at the car but only next week.

Clearly it seems to us that we have a faulty battery but any of you have experienced something similar? Or know what the problem might be ?

 

[Sparklebeard]

I think I recall another post a while back from someone who experienced a similar drop in range, however in their case it turned out they had solely been DC fast charging.

Hopefully VW sorts it out for you quickly, that’s terribly frustrating!

 

[miimura]

The range display in the car is not a direct indication of the energy stored in the battery. You have to use all the information presented by the car to figure out how much energy you're using. Have you done any drives that use more than 75% of the battery? If you are doing a bunch of small trips and using less than 50% of the battery before recharging, then you really have no idea how far the car can go.

If you follow the technique in the thread linked below, you will get an idea of the energy capacity of the car over time. Please read the limitations of the technique carefully because the values reported by the car have a relatively high uncertainty from limited significant digits and the display truncation or rounding.

Estimating Battery Degradation

 

[egolfEr]

Since your car is new...the battery is balancing the battery..typically trying to figure out how to predict range based on your driving habits (mi/Kwh), temperature, altitude, and other variables. If you are driving it gingerly and not getting 110+ real world miles out of the battery, then I would contact VW.

 

[f1geek]

egolfER, could you please share the evidence of this "new car" battery balancing? I am currently driving my second e-Golf and never observed this range loss behavior outside of heavy HVAC usage or a heavy right foot. To my knowledge, battery cell balancing is what happens near the end of a 100% charge cycle and is actually making very tiny adjustments to account for slight differences in individual cells. Battery balancing should not drop range by half. But, if you have evidence of this, please educate all of us.

 

[egolfEr]

50% reduction is quite a bit. There may actually be something wrong with the car.

I can only share my experience...when I got my first eGolf the range was consistently showing 125 miles at 100% SOC...in 2 months it was consistently showing 95 miles and 100% SoC.

Irrespective of the what is being displayed...are you only able to drive 62.5 miles or so?

 

[Sparklebeard]

It could be a battery problem, or it could be a computer problem causing it to calculate the range incorrectly. But honestly from what you've said I can't see there not being SOME sort of problem here. Unless you live at the peak of a mountain and tow the car to the bottom so as to only ever drive uphill, there's no way I could see it calculating 50km (35ish miles!!!) off a 90% charge, if im understanding correctly.

My only real question is to confirm that the battery IS being charged by the charge station, and there's not a charge timer set in the car that makes the car not actually charge while it's plugged in. It sounds like yours is showing a full battery gauge, but it doesn't hurt to ask!

 

[MarieMartin]

I don’t live at the top of a mountain, I live in Quebec and have driven quite normally since having the car.
It seems to be charging adequately since the battery gauge seems full after the charge but I did notice that the charge seems to stop faster than indicated. I mean when I plug it, it would say 4h until full charge but would stop after 2h with a full gauge.

I can’t wait to know what’s wrong with my new car...

 

[Sparklebeard]

I don’t live at the top of a mountain, I live in Quebec and have driven quite normally since having the car.
It seems to be charging adequately since the battery gauge seems full after the charge but I did notice that the charge seems to stop faster than indicated. I mean when I plug it, it would say 4h until full charge but would stop after 2h with a full gauge.

I can’t wait to know what’s wrong with my new car...

Would you mind describing what method you used to limit charging to 90%?

Is yours an SEL or an SE? I have noticed in the digital dash that the gauge looks "full" at 90%, and I feel like I have also observed the car charge duration on the dash calculate as if it were charging to 100%, but then stop at the maximum charge I have set earlier than the expected time. So this may not itself be a problem.

Does the battery gauge drain super quickly when you're driving? So if it says 50km range, and you drive 25km, do you see about half the battery disappear?

 

[f1geek]

Unless you need to charge to 100%, VW (and Tesla) recommend NOT to charge to 100%. To enable the maximum number of charge cycles, you should limit the battery cell voltage to 3.9 V, which equates to about 80% state of charge for the 35.8 kWh e-Golf. Charging the car to 100% routinely will enhance the rate of battery degradation. I have used OBDEleven to verify 80% equates to 3.94 volts per cell. Whether you are able to use 32 kWh or 30 kWh of the 35.8 kWh pack, what matters is cell voltage. You can only verify cell voltage with an OBD dongle/software setup. If you really need the full 100%, that's fine, but expect about 10X fewer charge cycles before you see significant degradation (as verified in peer reviewed scientific publications).

 

[JoulesThief]

VW never charges the battery to 100% state of Charge, only Tesla's do that. VW limits it to a maximum "full tank" showing in the dash gauge to about 90 to 91%, about 4.05V. You can charge a VW fully without worry of the battery degrading, if charged at Level 1 or Level 2 charging stations.

Using DC fast charging has in the past been recommended to be used sparingly. Read your Owners Manual for the recommendations.

Here, VW recommends setting the default charging to 98% or less. https://carnet.vw.com/web/vwcwp/e-golf

In Charging Preferences, what is Maximum Battery?

The maximum battery level is the amount of battery charge you want your e-Golf to have before it stops charging. The default target battery level is 100%. We recommend changing the default since frequent and consecutive charging of the high-voltage battery when the charge level is above 98% can also decrease the capacity of the high-voltage battery. Make sure the charge level is below 98% when you start the charging process.

 

[egolfEr]

This is correct..on the 24KwH batteries you could only use 22 Kwh

 

[JoulesThief]

This is correct..on the 24KwH batteries you could only use 22 Kwh

How many kWh can you now use on the 35.8 kWh battery on a 2017 through 2019?

 

[egolfEr]

No idea...probably 5-10%...maybe 32-34KwH is addressable

 

[f1geek]

VW does NOT recommend charging to 98%. If you read the excerpt, it says not to charge it IF the SOC is 98% or higher. A VW executive is on record recommending charging only to 90% (3.94 V) to be nice to the pack. Besides, you can't select 98% in the car - SOC is only available in 10% intervals. As I said before, charge to 80% if you want to make the battery last.

 

[JoulesThief]

VW does NOT recommend charging to 98%. If you read the excerpt, it says not to charge it IF the SOC is 98% or higher. A VW executive is on record recommending charging only to 90% (3.94 V) to be nice to the pack. Besides, you can't select 98% in the car - SOC is only available in 10% intervals. As I said before, charge to 80% if you want to make the battery last.

Find your quote, for all of us to read, of the executive.

 

[MarieMartin]

So I’ve had the car for only one week ans a half. It is an SEL.
The first two days, I had it charged with DC fast charging up to 80%.
Then the next three days, I charged it at home with the level 1 charger that comes with the car. There was nothing else on the circuit (my husband is an electrician and has already thought of this).
Then we received our level 2 charger at home and started using this the last four days.
Having not been told about the recommandation to limit the charge to 90%, I hadn’t done it yet but still, it’s been only one week charging to full capacity.

When I use the car, the loss in km range displayed on the dash does reflect the km that I’ve driven. Most of the time, I poorly use the climate control system. Since the problems began, the green gauge of recharging when braking has been getting smaller and smaller. Right now it has almost completely disappeared.

I kind of had a piece of answer last night when a light in my dashboard saying default : electric system appeared. I guess I’ll bring it to the workshop this morning instead of waiting for my next thursday’s appointement... Now I can’t charge it more than 1/4 of the gauge battery.

Thank you all for the advice !

 

[JoulesThief]

So I’ve had the car for only one week ans a half. It is an SEL.
The first two days, I had it charged with DC fast charging up to 80%.
Then the next three days, I charged it at home with the level 1 charger that comes with the car. There was nothing else on the circuit (my husband is an electrician and has already thought of this).
Then we received our level 2 charger at home and started using this the last four days.
Having not been told about the recommandation to limit the charge to 90%, I hadn’t done it yet but still, it’s been only one week charging to full capacity.

When I use the car, the loss in km range displayed on the dash does reflect the km that I’ve driven. Most of the time, I poorly use the climate control system. Since the problems began, the green gauge of recharging when braking has been getting smaller and smaller. Right now it has almost completely disappeared.

I kind of had a piece of answer last night when a light in my dashboard saying default : electric system appeared. I guess I’ll bring it to the workshop this morning instead of waiting for my next thursday’s appointement... Now I can’t charge it more than 1/4 of the gauge battery.

Thank you all for the advice !

Stay off of that DC fast charger, that's the majority of your problem. You don't tell us how many KM's per day you are driving, nor do you tell us how many kWh per 100 km you usage rate is. Read your owners manual to find out how to find that in the infotainment center, then take some pictures of the screen and post up here.

You really need to read your owners manual completely on how to recharge your car... one of your settings is off, it sounds like it's waiting to charge up at off peak hours, and you don't have a fast enough recharge rate at your home, for the amount of KM's driven daily.

Try looking and understanding the settings, in the owners manual, and leave your car parked at home on the Level 1 charge for 30 consecutive hours, without driving.

Also do yourself a favor, dress appropriately and turn off all the AC or heater and fan features so you get less kWh used per 100 km... Turn off as many accessories as necessary until you figure out what's sucking your battery's charge down.

 

[MarieMartin]

I used only twice the DC fast charging and it was directly at the VW dealership the first two days.

I did read the manual and I have looked at all the settings. This is not the problem. I might have not well expressed mysef (my first language is french sorry) but I didn’t use the AC since having the car.
I did 10-40 km per day in the last week. My average kwh/100 km has been 13-16 since having the car. We tried leaving it on charge a full day without driving.
I have taken a lot of pictures but don’t know how to post them here.
I went to the workshop this morning, the service manager confirmed there is something wrong with the car, maybe the cell battery, he suspects it could take a couple of weeks to look into it.

 

[JoulesThief]

I used only twice the DC fast charging and it was directly at the VW dealership the first two days.

I did read the manual and I have looked at all the settings. This is not the problem. I might have not well expressed mysef (my first language is french sorry) but I didn’t use the AC since having the car.
I did 10-40 km per day in the last week. My average kwh/100 km has been 13-16 since having the car. We tried leaving it on charge a full day without driving.
I have taken a lot of pictures but don’t know how to post them here.
I went to the workshop this morning, the service manager confirmed there is something wrong with the car, maybe the cell battery, he suspects it could take a couple of weeks to look into it.

Please post up the work ticket once the dealership has fixed the problem, with what parts are replaced.