charging to 90%

[Rsolaregolf]

We've had our eGolf for about 16 months/8000 miles. We charge it to 90% using the car-net remote. The last few times we've charged it, it charged to 100% even though the charge is set to 90%. This AM I checked it and it was at 90% and not charging, exactly what it has done all along until recently. Not a big deal but I was wondering if anyone else has seen this happen to their car.

 

[JoulesThief]

Wish I could help you, but VW only charges up 21.2 kwh out of a 24.2 kwh battery. The point being that even if the gauge shows the battery is fully recharged, it's only been recharged to maybe 92 or 93% of it's true capacity. VW engineers this into every recharge, so that Joe Blow consumer doesn't have to compensate for it, and so that VW will have a battery that lasts the full warranty period. Your "90%" state of charge really leaves the battery at 83 or 84% true state of charge.

 

[f1geek]

I have not seen this happen. But it does raise this question: Why does VW allow variable max charging SOC% if "it doesn't matter"? I have seen data suggesting keeping the battery around 50% SOC will extend its life. VW (and other car manufacturers) let us charge to lower limits to help extend the life of the battery. By default, Tesla limits the SOC at "full" charge to less than what is available in Trip mode, so Tesla can extend the life of the battery for the average "Joe" driver.

 

[mfennell]

I can recall no evidence showing what the true percentage "100%" on the gauge relates to in an e-golf. 100% in a Model S has been measured to be a true 100% (4.20V/cell I think). The Roadster was limited to 95% IIRC.

With 20-50 miles per day, I charge to 90% most of the time. 80% in summer. That usually gets me back home at 40-60%, perfect if I'm not driving the car the next day.

Of course, I'm leasing, so some future driver will benefit from my treatment of the battery. I doubt it will make a measurable difference over the course of my lease.

To the original poster, my '15 has never exceeded the limit I set via car-net.

 

[Rsolaregolf]

To the original poster, my '15 has never exceeded the limit I set via car-net.[/quote]


our either until the past week or so???

 

[jack8trades]

We've had our eGolf for about 16 months/8000 miles. We charge it to 90% using the car-net remote. The last few times we've charged it, it charged to 100% even though the charge is set to 90%. This AM I checked it and it was at 90% and not charging, exactly what it has done all along until recently. Not a big deal but I was wondering if anyone else has seen this happen to their car.

Do you check, when you plug in, that the top button isn't lit, as in this picture?

That indicates a delayed charge isn't in effect, possibly from pushing that button. If the bottom button is never lit, even before plugging in, or directly pressing the button, there is no delayed charge programmed into the car, from car-net.

Also, your carnet settings are, 90% minimum battery, and 90% or less for the maximum battery setting in the battery profile used for the enabled schedule, correct?

 

[forbin404]

We've had our eGolf for about 16 months/8000 miles. We charge it to 90% using the car-net remote. The last few times we've charged it, it charged to 100% even though the charge is set to 90%. This AM I checked it and it was at 90% and not charging, exactly what it has done all along until recently. Not a big deal but I was wondering if anyone else has seen this happen to their car.

Do you check, when you plug in, that the top button isn't lit, as in this picture?:

Also, your carnet settings are, 90% minimum battery, and 90% or less for the maximum battery setting in the battery profile used for the enabled schedule, correct?

90% Min turns off the delayed charging for the most part.

 

[jack8trades]

We've had our eGolf for about 16 months/8000 miles. We charge it to 90% using the car-net remote. The last few times we've charged it, it charged to 100% even though the charge is set to 90%. This AM I checked it and it was at 90% and not charging, exactly what it has done all along until recently. Not a big deal but I was wondering if anyone else has seen this happen to their car.

Do you check, when you plug in, that the top button isn't lit, as in this picture?:

Also, your carnet settings are, 90% minimum battery, and 90% or less for the maximum battery setting in the battery profile used for the enabled schedule, correct?

90% Min turns off the delayed charging for the most part.

I don't care about delayed charging, only limiting to 90%

There's no indication here that the OP cares about delayed charging either, but it's a valid concern. If so, the minimum battery should be set to a lower percentage.

Mostly, since the OP's settings worked for so long, I'd pay attention to those button lights.

 

[Rsolaregolf]

All delayed charging is off and the normal green charging light is on. We don't use delayed charging as we get our power from out solar tracking array or off the grid at night, no price differential from our electric coop.

I called carnet and they are looking into this for me. I'll post what they tell me.

 

[Rsolaregolf]

So carnet called yesterday and said that the reason it's charging to 100% might be that I have the timers shutoff. Unless they recently changed parameters, that wouldn't account for the fact it used to work OK with the timers off. They told me to turn on timer 1 and see what happens. (sounds like they may be guessing) As the battery is presently at 100% it will have to wait until we drive it somewhere which might be a few days, I'll report my findings.

 

[Verkehr]

It's not just you - mine mysteriously charged to 100% on Tuesday August 8.

I didn't touch the timer and it normally goes to 60% so that was a surprise.

 

[Rsolaregolf]

That kind of confirms my suspicions.

 

[jack8trades]

So carnet called yesterday and said that the reason it's charging to 100% might be that I have the timers shutoff. Unless they recently changed parameters, that wouldn't account for the fact it used to work OK with the timers off. They told me to turn on timer 1 and see what happens. (sounds like they may be guessing) As the battery is presently at 100% it will have to wait until we drive it somewhere which might be a few days, I'll report my findings.

If you examine the logic of the how the system should work, you can see that if charging was limited to anything below 100% with no timers turned on, then that's when charging was not working correctly.

The minimum charge parameter (on the main battery page of the web-based car-net, for example) is only there to make sure your car gets a minimum level of charge -- whatever it's set to -- when you get home and plug in. That way, if you need to make an emergency trip before the timer program kicks in* and charges the battery fully**, you might have enough juice. Also, it can prevent the battery from sitting unnecessarily at a very low state of charge, say 10% after just getting home from a long drive; which is not good for it, while waiting for the timer to start.

If there's no timer in effect, then there's no maximum charge level in effect, so no timer enabled should = 100% charge.

To take advantage of maximum level charging even though you don't care about a timed charge, you still need to use a timer to (reliably) enable a maximum. Just set the minimum charge to your desired maximum setting, and make sure the enabled timer specifies a location setting with a maximum charge level of the same, or less, than that.

* to take advantage of lower electricity rates at night
** to the maximum set in the location parameter used by the timer program.

 

[Rsolaregolf]

Thanks for pointing out a number of things I wasn't aware of. My point is that before a few weeks ago with 1 timer on it charged to 90% as it was set on car-net then all of a sudden it charges to 100% and I changed nothing.

 

[f1geek]

This past weekend I saw some strange charging events. I have my car set to charge to 100% using L2 charging but I observed the charging process stop short of 100% even though I did not change anything on the charging settings. On the dash the fuel gauge was at the last tick before full but in Car-Net all the bars were green.

Maybe VW is performing some software updates on Car-Net that is affecting the %SOC drivers choose?

 

[Rsolaregolf]

VW care called the other day asking if I was still having issues. I still am as it is still charging to 100% so they stated they are looking into it with the technical folks and will get back to me tomorrow.

 

[Rsolaregolf]

Check it just now after a trip running down to ~50%, this time it did charge only to 90% ??????

 

[Rsolaregolf]

A car-net tech called last evening to see about the status of our eGolf. For the past couple days it has once again been charging only to 90% so all is good as far as we are concerned. Tech didn't say what happened to make it correct but IMHO it was something on their end that was changed and then rectified to get us back to 90% charging.

 

[whyeGolf]

FYI: The BMW i3 has the same battery management behavior in that it only allows you to charge to 90% and discharge down to 10%, even though the display states 100% and 0% (or on the i3 shown as "-- --". But the i3 nor the i3 app on the iPhone does not allow any pre-setting of 90% charging limit. At least the VW has a way to set an aid to improve the battery life.
And a little off topic but related to failure to of holding a set charge level: The real pain with the BMW i3 Rex model is that if you have the BMW i3 Rex (Range extender with 650cc generator set), the CARB rules prevent it from operating as designed (like the rest of the world) - therefore in the USA there is a 43 state (Non-CARB states) and Canada class action law suit against BMW.

 

[Rsolaregolf]

FYI: The BMW i3 has the same battery management behavior in that it only allows you to charge to 90% and discharge down to 10%, even though the display states 100% and 0% (or on the i3 shown as "-- --". But the i3 nor the i3 app on the iPhone does not allow any pre-setting of 90% charging limit. At least the VW has a way to set an aid to improve the battery life.
And a little off topic but related to failure to of holding a set charge level: The real pain with the BMW i3 Rex model is that if you have the BMW i3 Rex (Range extender with 650cc generator set), the CARB rules prevent it from operating as designed (like the rest of the world) - therefore in the USA there is a 43 state (Non-CARB states) and Canada class action law suit against BMW.

When our charge gauge indicates 100% we get no regenerative braking. When it charges to 90%, as it is once again doing, the needle is down between the 1st and 2nd tick marks on the gauge. Regenerative braking works fine then.

So you are saying when the gauge indicates 100% it is only charged to 90% and regenerative braking doesn't work above 90%, correct?

Whatever, it's back working the way we want it to.