Regen braking unavailable while at Standard full charge

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n3ckf

Well-known member
Joined
May 13, 2013
Messages
366
Location
Volcano, CA
Something interesting occurred to me the other day and i think this is a "bug" in the car.

My house is at 3300' in the mountains and i often drive downhill from here if i go into town (the main town around here is at 1500').
So i had charged the car to a standard charge when i arrived here, then went into town the next day.

Halfway down the hill i got the "regen braking unavailable" alert.

But i had the charge at "standard". So there's a full 15% of the battery pack "available" to suck up additional charge from braking.

I am used to seeing this when i did an extended charge to drive a long distance (like back to the Bay Area). Howewver i'd never seen it, when at a standard charge level before.

My opinion: this is a bug. It shouldn't disable regen braking when there's capacity available in the battery pack. Especially since in most cases where this happens, you're going to run that charge back out a few miles later (you wont go downhill *forever*). If you did go downhill long enough to fill 15% of the battery pack (thats a big mountain) it could shut off *then*, since it obviously knows how to do so.

Anyone else notice this?

Anyone have a Tesla (which has the same concept of standard and extended i think?) and notice how this works on the Tesla?
 
Yes... I have seen this same behavior. Mine, mostly back in April when new, would give this message when I would leave work after sitting uncharged all day outside. I found it odd because it would happen with 14 bars showing, plenty of room for regen. It may have something to do with outside temperatures cooling the pack because I hadn't seen it all summer until last week, after the car sat outside overnight at 40 degrees and unplugged. It also has always happened in B mode, but I always drive in B mode... so go figure. Either way... it always goes away after a few minutes on the road. I don't think its a bug. I believe the car wants to limit high current regen for some reason.
 
What was the temperature at the time (and overnight)?
Were you using B or D?

Like Doug401 says, B will allow greater regen levels to occur and lower temperatures will increase the pack's resistance such that at high regen levels the overall voltage shoots up quickly and may reach a preset threshold earlier than normal.

Try programming the climate control to turn on 15 minutes before you leave which might precondition the pack and normalize everything.
 
so when this happened it was kind of mid-day (probably 70-75F outside)? The car had finished charging (to standard) about 12 hours earlier though (at night when it was 45-50).

I was using "B" which i mostly do when on mountain roads.
 
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