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 Post subject: Regen braking unavailable while at Standard full charge
PostPosted: Wed Oct 09, 2013 11:47 pm 
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Joined: Mon May 13, 2013 6:15 am
Posts: 320
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?

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 Post subject: Re: Regen braking unavailable while at Standard full charge
PostPosted: Thu Oct 10, 2013 5:20 pm 
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Joined: Sat Mar 16, 2013 4:52 pm
Posts: 100
Location: Lake Stevens Washington
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.

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 Post subject: Re: Regen braking unavailable while at Standard full charge
PostPosted: Thu Oct 10, 2013 6:36 pm 
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Joined: Sun Mar 03, 2013 2:26 am
Posts: 304
Location: Austin, TX
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.

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 Post subject: Re: Regen braking unavailable while at Standard full charge
PostPosted: Sat Oct 12, 2013 4:45 am 
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Joined: Mon May 13, 2013 6:15 am
Posts: 320
Location: Volcano, CA
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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