No, It’s Real: EV Range Down

Again, good thoughts; thanks!

Excellent! Thanks again.

 

I am driving my commute entirely on EV.

Those numbers (originally 6KWh down to 5KWh) are how much ChargePoint reports for charging it to full from “empty,” meaning the EV-HV threshold.

8.8KWh, although there are 10-15% top and bottom margins, plus of course ... something like 800Wh for Hybrid-mode operation.

Thanks, that’s my impression as well. Plus it’s only about a year and a quarter.

I suspect that the batteries themselves are intact, but the computer is blocking off some of the top end to increase the top charging margin, to improve long-term battery life. That, probably in response to higher (outdoor) temperatures and the fact that I’ve been leaving it mostly charged overnight.

I’m testing that Theory now by going back to charging mostly right before hopping into the car.

 

Good info. 15% degradation after how long?

 

Interesting...

Well FWIW, it’s currently sitting at about the official 22-25 mile range promised...

Did it degrade in 2-3 mile steps like I saw?

That is, 4ish weeks ago it dropped instantly 31 to 27 (one charge got 31 miles and the next was 27), then it stayed there at 27ish, until about a week ago when it instantly dropped to ~25 (again, one chafe was 27ish, and the next was ~25, and it’s been sticking there.

Or was it a more or less continuous, gradual degrade?

 

“That” meaning it’s range dropping in distinct steps?

 

Indeed, about 6KWh originally, now about 5KWh.

I suspect there are, not surprisingly, several factors involved here:
1. Warmer temperatures so the computer doesn’t want to push the batteries too much.
2. I’ve recently been not going directly home from work, but instead going to the local mall to charge up on the Austin Energy $1 per week “all-you-can-charge buffet” rather than doing a scheduled charge at home right before I leave the following day. Therefore, it’s spending more time (all night) closer to the to limit of the battery, so the computer has expanded the top charging margin.
3. The Guestimatron has changed its estimation parameters, in response to all of this and greater air-conditioner usage. This makes assessing how much the battery capacity has changed ... a little cloudy.
4. Of course, how many miles I’ve gotten in he past per charge has varied some, historically, again making it a little cloudy.

However, the drop in amount charged, from 6KWh per charge down to 5, is a clear, objective, measurable difference — nothing “cloudy” there.

 

OK, two new data points:

First data point: Yesterday evening, I drove straight home from work (i.e., instead of charging at the local mall on the way home, as I have the last 2-3 months). Historically, when I have driven directly home, upon arriving at home, I would have about 11 miles predicted EV range. This time I had about 4 miles. In both cases, this is after charging to “full” (which ChargePoint says is about 1KWh less now) at work.

Second data point: This morning, I drove to my rowing club and back on a single charge, after charging to “full” at home. Historically, when I did drive directly home, I would make it back home with about 4 miles of predicted EV range left. This time, I had -0.4 miles (the ICE kicked in 0.4 miles before arriving home). Both of these data points are without using the air-conditioner.

 

So, the concept would be that, if I insist upon spending more time at the top limit of the battery, it will lower that top limit, in order to reduce wear upon the battery.