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Resumption of charging after vampire loss ...

Resumption of charging after vampire loss ...

Once charging is complete (at whatever level it is set to) and the car is left to sit overnight with UMC still plugged in, at what point would the charging automatically resume once the charge level starts to drop due to vampire loss? Is this threshold point selectable?

If i physically unplug and replug in the UMC cable, charging would start again but i was wondering if it can automatically resume charging without me intervening.

KOL2000 | June 11, 2013

I just went on a trip and left it plugged in and it charged it every night back up to my prespecified level. So the answer to your question is yes.

Brian H | June 11, 2013

It seems to require quite a drop, 20 or 30% or so. Some prefer slow low-amp continuous charging timed to finish about when needed for this reason.

nickjhowe | June 11, 2013

On my P85 it used to cycle between about 235 and 242 miles. With 4.5 most of the vampire load should be handled by shore power; it will probably still cycle down to 235 miles but take much longer.

DTsea | June 11, 2013

its more like a 10~15 mile drop for my car.

sia | June 11, 2013

My experience is similar to @KOL2000:
I charge overnight; and in the morning, it always has 243 Rated Miles (assuming I have Max Charge level set to 90%). So if there is some vampire loss, it is compensated from the power outlet, not the battery.

One other data point: If I leave it unplugged overnight, it will lose 3 to 5 Rated Miles in about 8 hours.

jnb | June 11, 2013

I charge mine at night starting at 10pm. most of the time for daily driving it only charges for a couple of hours (even when set to 10A). by 9 am the next day its is down to 238 miles or so. So if it kicks back in, it does it below 238.

What we need is charging start and end time so that the car can figure out how fast to charge the car so that it is done when you want to drive it.

stevencoberly | June 11, 2013

But, just to be clear, it doesn't matter, right? I have to think 99% of the time, you will have plenty of charge to complete your day of driving, whether the S was charged to 241 or 233 or 220 or whatever. And if the difference at that level mattered, you would have presumably charged to Max range in the first place. Or am I missing something? I am just planning on putting vampire loss way up at the top of my list of things I am not going to worry about.

sia | June 11, 2013

@Scoberly: I agree.

As I mentioned, I am getting an insignificant amount of vampire loss: about 0.5 Rated Miles per hour.

hamer | June 11, 2013

I have on several occasions driven my car to the airport and left it for multiple days up to 5 or 6 (unplugged, not charging). How much vampire loss there will be will to some extent depend on the outside temperature. I can monitor day day with the app what the remaining charge is. In the spring (that is, not winter cold nor summer hot), it seems to lose about 10-12 miles of charge per 24 hour day just sitting there doing nothing. That would match fairly closely what @sia said was about 0.5 rated miles per hour.

hpatelmd | June 11, 2013

+1 @Scoberly

Brian H | June 11, 2013

@Scoberly;
The other reason it doesn't matter is the actual charge is unchanged, just the calculated mileage display. The new miles are a bit longer than the old miles, so fewer "fit" in. ;)