Variable Hilltop Reserve charge

[randW]

I use Hilltop Reserve when I do not need a full charge for the next day and have been seeing that the battery charge seems to be getting less and less. When I first started using Hilltop Reserve, I got a charge of 210 or so miles. My latest charge was 167. Any idea why?

 

[WetEV]

I use Hilltop Reserve when I do not need a full charge for the next day and have been seeing that the battery charge seems to be getting less and less. When I first started using Hilltop Reserve, I got a charge of 210 or so miles. My latest charge was 167. Any idea why?

The usual reason why full charge range varies is that conditions change. Some examples include:
During winter due to cabin heating, batteries holding less energy at lower temperatures and so on.
Roads wet or snow packed.
Driving faster.
Wind.

 

[user 387]

I'd suggest you measure the charge in % of full charge, not on the guesstimate of miles you can drive on the current charge (which is based on recent driving, HVAC use and weather).

 

[PackardV8]

It's probable the car computer is learning your driving profile and adjusting the range prediction based upon history, rather than the initial startup algorithm.

Distance, speed, regen use, load, HVAC use, external temps all make a difference.

jack vines

 

[boltage]

If your recent driving has been less economical (e.g. heater use, higher highway speed, roof rack), then the predicted range will be lower for the same level of charge (hill reserve mode fills it to 87-90%).

 

[gpsman]

All of this is true.

Also be sure to do a complete charge once a month so the batteries can balance and the guess-o-meter (and you) don’t have to guess how full it is.

Measuring electrons is a lot harder than measuring gallons.

Once I went to a DCFC after a long time of never reaching 100%. It took 16 kw all the way to 100% which isn’t supposed to happen. Then, the guess-o-meter instantly reset from 100% to 86% and I continuted to charge at lower power rates (16kw, then 10kw, then 6kw, then 3kw) until it hit 100% a second time.... hopefully the real, newly re-calibrated 100%.

 

[GetOffYourGas]

Once I went to a DCFC after a long time of never reaching 100%. It took 16 kw all the way to 100% which isn’t supposed to happen. Then, the guess-o-meter instantly reset from 100% to 86% and I continuted to charge at lower power rates (16kw, then 10kw, then 6kw, then 3kw) until it hit 100% a second time.... hopefully the real, newly re-calibrated 100%.

When this happened, how long had it been since you charged to 100%?

I've currently set up my car to charge to about 65% M-Th (with an departure time several hours after I leave work). I then charge to 90% on Friday ahead of the weekend. Unless I have a long trip, in which case I'll go to 100%.

That said, I'd love to have a feel for how often the Bolt really should be charged to 100%. In addition to calibrating the BMS, does the car balance the cells better at the top end? How far out of calibration / balance would the car get if I went multiple months never charging past 90%?

 

[gpsman]

I went for 7 or 8 weeks (2000 miles +/-) without ever going to 100%. After my charging experience, I now make sure to go to 100% once or twice a month.

I always drive right away (ok, within an hour or two) after hitting 100% so my car does not sit there very long.