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See the Gigacapacitor thread for a discussion of how supercapacitors/ultracapacitors could help address the problem being discussed here. They are much less temperature sensitive than lithium ion batteries and have a greater power density, so could serve as a buffer between large amounts of electrical current (from Superchargers or full regen braking) and the battery at times when the battery can't accept that much (primarily when the battery pack is cold or when it's nearly full). Likewise, they could dump larger amounts of current into the motor than the batteries are capable of releasing for short bursts of acceleration. Seems like a natural upgrade option for future generations of Teslas when a higher degree of convenience and longer battery lifetimes are desired.
islandbayy
Active Member
As soon as the Supercharger was plugged in, the pumps started pumping. I didn't want to touch anything on the car just in case. It was cold soaked. I had low 12v warning, and the car was disabled due to low main pack. So I wanted to just let the car do it's thing. Sure I froze, but I didn't want to risk draining anything more until I had at least some increase of charging speed and at least some increase in % of the main pack. Once I had 1 rated mile and a few kW in charging speed, I started with seat heater, then once I had about 20 miles on the pack and about 10kW charging speed I flipped on the heater. I couldn't risk it not charging, especially if the 12v battery froze. It was 11 degrees F out.
Except by design you need to keep as much charge in the super capacitors as possible at all times. So using them to buffer battery charging wouldn't work very well, as they wouldn't be able to take much additional energy on board.
Hmm... full throttle acceleration onto the highway... get off the next ramp and turn around... repeat until full regen is available!
My car was parked outside from 8am to 4pm while I was working. Then I drove 10 minutes to the supercharger & plugged in. The regen said it was disabled so I did know the battery was cold. But it was a frustrating experience since I was on a tight schedule & had planned 20- 40 minutes to charge in order to get to my next stop on time. Like I said, 1-2 hrs if your battery is cold and you want to fill up is what you should plan. I stopped charging at 190 miles and got to next stop with only 20 miles left in my battery which definitely created some range anxiety.
In anticipation of winter - in that we'll be heading back to Alaska for May and thenceforth - this thread appears, unfortunately, to be timely for me. Is there not a simple means to force a batterypack warmup? That would seem to me to be an easy task for the cars' systems to accomplish.
Makes sense in that case. Thanks.
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The cabin pre-heat seems to warm the battery pack to a certain level... we just don't know whether that allows for full supercharging after 30 minutes or so of pre-heating or whether it requires more than pre-heating can do.
(LMB spouse)
We had the same experience as EdA while heading back to Boston from the DC Tesla rally last month. We stayed overnight at a motel a few miles south of the Delaware supercharger. There was no place to plug in overnight and I think the temperature was in the low 20s when we left next morning. There was no appreciable battery heating in the few highway miles to the Newark SC. It took a long time to ramp to 50 kilowatts and by then we were into the taper. I seem to remember an hour and 15 minutes to charge from 80 rated to 240ish, but I didn't take notes. I think we preheated the cabin to 65F, though.
We had the same experience as EdA while heading back to Boston from the DC Tesla rally last month. We stayed overnight at a motel a few miles south of the Delaware supercharger. There was no place to plug in overnight and I think the temperature was in the low 20s when we left next morning. There was no appreciable battery heating in the few highway miles to the Newark SC. It took a long time to ramp to 50 kilowatts and by then we were into the taper. I seem to remember an hour and 15 minutes to charge from 80 rated to 240ish, but I didn't take notes. I think we preheated the cabin to 65F, though.
mknox
Well-Known Member
Is that wise? I have been operating on the assumption that if re-gen is being limited, I shouldn't be punching it and drawing too much power OUT either. I go gingerly until the battery is warmed up as signified by little or no re-gen limit.
JJR64
28680
Doesn't heating the cabin also warm up the battery pack? If so, couldn't he have just used the phone app to start warming the car 30 minutes before he was going to drive it to the SC?
I figured this out through experience at the Somerset SpC. I spent a weekend at 7 Springs Ski Resort and the car was parked outside in the cold for two days. We left Sunday Afternoon and when we hit the Somerset SpC (after about 10 miles of driving) the charging rates were definitely slower. While not as slow as the OP has described it was around ~40 kwh. While the charge rate did increase as the battery warmed more I never saw 120kwh or 90kwh for that matter. We stayed to get enough charge to get the Hagerstown SpC then left. Showed up at Hagerstown after a very cold, very hilly, and VERY snowy trip with 17 miles left. I wanted a 25 mile buffer but my calculations were close enough.
I was just about to reply with the same suggestion. This is an education problem more than anything else. Unfortunately, ICE cars fill at the same rate regardless of the temperature of the gas tank. For EVs to hit the main stream, Tesla needs to everything they can to eliminate friction points like this one. Battery swap would have solved this problem. Increasing the size of the heat pumps might have helped as well (2 degrees change per minute instead of 1?). But when you add the marginal cost both in terms of dollars and size/weight of the pumps into the equation against the number of drivers and situations when a larger heat pump would have helped, my guess is you end up with the conclusion to reduce costs. You have to aim for the 80% mark, not 100%.
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