Is battery capacity impacted by frequent 100% L2 charging?

[eGopher]

I have never been able to get a definitive answer to the battery life question:
Is battery capacity impacted by frequent 100% L2 charging?

The printed manual says one thing, car-net says another.
Sunnyvale VW doesn't know nor does VW customer care.

If I use a level 1 or 2 charger, is there any reason I should stop at 90% charge ?

Doesn't the vehicle already limit the charge to 87% (using only 21KW out of the 24.2?)

I plan on keeping the vehicle for at least 5 years; so preserving battery capacity matters to me.

 

[miimura]

In my opinion, VW has already put a buffer at the top of the battery to prolong its life. The only warning they have in the manual is not to start charging if the state of charge is above 98%. The silly thing is that they don't give precise data about the state of charge so you actually know the percentage with that one or two percentage points accuracy.

In other words, I wouldn't worry about it.

 

[JoulesThief]

My car usually shows a range of 129 miles if started charging with 60- 70 miles of range left on it. 1% of 129 is 1.3 miles. Taking 2% of that would tell me not to attempt to recharge it unless lower than 2.6 miles or 3 miles rounded up, off of 129. So I need to be a fair bit lower than 126 miles before recharging.

 

[jack8trades]

My car usually shows a range of 129 miles...

Good luck using range as a reliable indicator of battery capacity.

 

[JoulesThief]

My car usually shows a range of 129 miles...

Good luck using range as a reliable indicator of battery capacity.

It's used only as a number, for percentage purposes, nothing more, nothing less.

 

[mfennell]

Doesn't the vehicle already limit the charge to 87% (using only 21KW out of the 24.2?)

I plan on keeping the vehicle for at least 5 years; so preserving battery capacity matters to me.

If long term is your goal and 90% meets your needs, I'd do it.

First, that 87% (assuming it's actually that - do we really know?) is distributed top and bottom. You may be charging to 95% of actual capacity.

Second, and this is my cynicism sneaking through, VW would have done everything it could to keep costs down with this car. Battery size/layout was probably fixed long before they really knew what the range would be BUT they had a hard target of low-80s to get those CARB credits. If they come up a little short, what are they going to do? Dig deeper into the pack and hope warranty claims don't cost more than the redesign would have.

On the off chance I might buy the car at end of lease, I delay charge to 90 and only charge it when I plan to use it (I have other cars). Since my days are 25-45 miles, it doesn't impact my driving at all and I think it will pay dividends in the long run.

 

[JoulesThief]

Doesn't the vehicle already limit the charge to 87% (using only 21KW out of the 24.2?)

I plan on keeping the vehicle for at least 5 years; so preserving battery capacity matters to me.

If long term is your goal and 90% meets your needs, I'd do it.

First, that 87% (assuming it's actually that - do we really know?) is distributed top and bottom. You may be charging to 95% of actual capacity.

Second, and this is my cynicism sneaking through, VW would have done everything it could to keep costs down with this car. Battery size/layout was probably fixed long before they really knew what the range would be BUT they had a hard target of low-80s to get those CARB credits. If they come up a little short, what are they going to do? Dig deeper into the pack and hope warranty claims don't cost more than the redesign would have.

On the off chance I might buy the car at end of lease, I delay charge to 90 and only charge it when I plan to use it (I have other cars). Since my days are 25-45 miles, it doesn't impact my driving at all and I think it will pay dividends in the long run.

Charge to 90? 90 what? 90 miles range? Nothing shows me what a 90% charge would be, if that is what you meant.

 

[miimura]

Charge to 90? 90 what? 90 miles range? Nothing shows me what a 90% charge would be, if that is what you meant.

The only way you can reliably charge to anything but 100% is to use the CarNet app to reduce the Max Charge level. It used to be settable in 5% increments, but at one of the recent app updates, they changed it to 10% increments, which is stupid. So, the next greatest option below fully charged is whatever the car thinks is 90%.

The right way to read the battery level is the small inset gauge on the right side of the instrument panel. It is graduated in 16ths. To follow VW's suggestion to avoid charging when the battery is too full, I would suggest that you wait until the needle is about half way between the top and the first tick mark down on the gauge. That would be 31/32=97%

The image below is 11/16 which is about 69%.

The mile range estimate is completely dependent on your driving efficiency and changes from day to day and driver to driver.