I had exactly the same situation. Normally if I leave home with 90% I can get up to Ferrybridge with 12%. So I charged to 97% and the expected percentage at ferry bridge started off at 19%. As we went up the temperature outside dropped to below freezing and the anticipated arrival percentage started dropping. With 50 miles to go it was down to 13% even though I slowed to 60mph. The trouble, I suspect, was as it kept dropping and I kept slowing the pre-conditioning was going to be on for longer. I was down to 46mph and it was down to 5% but still dropping. It never suggested an alternate even though we sailed by Woodall as it (and I at the time) did not know one can access the southbound supercharger. Eventually I sped up and I arrived with around 7%. I would have changed the location but I did not want to miss my turning.
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Battery Preheat - Down side
- Thread starter piffmunday
- Start date
I think there’s a bit of confusion between preconditioning the car (warming the cabin and maybe heating the battery before you start your journey) and preheating the battery whilst heading to a supercharger for optimum rapid charging in some of the early replies the post is about the latter
Pre heating the battery for supercharging uses a lot of extra energy so yes, I’ve noticed it. It also used to do this over a long period, say you put a supercharger in the sat nav that’s 2 hours away it starts (or used to) from quite some distance. They may have fixed it but I now dont put in a supercharger location until only about 15 mins away as the drain seems otherwise excessive.
The car also (at least used to) not take into account the higher energy use before reaching a supercharger was due to the preheat and factored in similar inefficiency for the next leg resulting in a massive over charge recommended. Again this might be fixed now, I avoid using it that way to find out because it was so misleading
Pre heating the battery for supercharging uses a lot of extra energy so yes, I’ve noticed it. It also used to do this over a long period, say you put a supercharger in the sat nav that’s 2 hours away it starts (or used to) from quite some distance. They may have fixed it but I now dont put in a supercharger location until only about 15 mins away as the drain seems otherwise excessive.
The car also (at least used to) not take into account the higher energy use before reaching a supercharger was due to the preheat and factored in similar inefficiency for the next leg resulting in a massive over charge recommended. Again this might be fixed now, I avoid using it that way to find out because it was so misleading
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ACarneiro
Active Member
Oh, this is interesting.
I almost never use DC charging and when I do it tends to be Superchargers. I didn't realise battery preheating also now happened when you navigate to non-SuC rapids? When did this become a thing?
Drew57
Active ember
Back in 2020 preconditioning seemed to happen about 15-20 mins from a SuC. Sometime after, it changed to pre conditioning almost as soon as the location was selected regardless of distance. So since then I merely enter the address and accept that the charging stop takes a little longer (on my most frequent journey via the Rugby SuC, I stop just long enough for the loo & a coffee which is about 15-20 min & this easily covers the remainder of the trip with ~20% to spare even though the car only charges at ~75-80kWh).
I reason that fewer kWh added at a slower speed doesn't actually use much more time than more kWh (to replace the extra losses) but at a faster speed. The cost may also be lower for the former.
I reason that fewer kWh added at a slower speed doesn't actually use much more time than more kWh (to replace the extra losses) but at a faster speed. The cost may also be lower for the former.
I'm pretty sure it wasn't pre-conditioning, it's just that the electrons don't move well when cold. If you waited until the day warmed up, you would have had more range.
Turning the cabin down to a temperature wasn't helpful, turning the system OFF would have been recommended.
I suspect that as you turned the car off previously, the "You'd better charge now" message popped up. It's there for a reason. It's way to common for someone to come home in the evening with 10%, park the car and wake up with only a percent or two remaining.
You basically kept knocking a number of dominoes over.
It was midday and I had already done 30-40 miles in the morning (probably 2 hours before) so no it wasn't cold or early in the morning, it made a massive difference to the Wh/mi when navigating to the charger. I know what my normal rate is and it isnt 300+.
Not putting in a supercharger until nearby though, somewhat complicates route planning on a long trip. I'm not referring to a single supercharger stop on a trip but say a European roadtrip with multiple stops. It would be a pain to then have to go and edit each of those.
Alternate would be to leave out charging stops and then manually select each time but then there's no route optimisation around chargers and stop times.
I agree it’s a pain, but so is losing 15% of your range because the cars constantly heating the battery. I rarely do long journeys alone so I get Mrs S to enter service locations and then switch to the supercharger if it’s cold. If it’s warm, greater than 20 degrees, even that’s not really needed.
My next SC trip is at the end of March, i'll see how it fairs then. After that it's a trip to Italy in May, so based on the March drive, i'll consider prepopulating ahead. It would be nice to be able to save an entire route in the satnav to flip between one with SC planning and one without but I guess the idea is that none of this should be needed. Tesla magic should be supreme.
I would like to see a degree of intelligence built into the system. It always pre-conditions most of the way down the M1 only to arrive at Newport Pagnell to fight over half of 120kW.
Drew57
Active ember
There seems to some ( a lot ) of confusion on how preconditioning and Supercharging and navigation works.
Preconditioning won't occur at less than 20% Soc
If you put in a trip, the nav will automatically add Supercharging sites. (you can remove if you desire)
They do it the right way. No user intervention is required.
The OP problem wasn't preconditioning, it was a short trip, which uses more than normal. And no matter what, they made it. They were playing on the edge and didn't fall off.
yep and then it digressed to general comments about the car starting to precondition the battery enroute to a supercharger, using energy that they'd prefer not to use.
I didn't have an issue with the way it works on a trip to Switzerland but for some people, 30 minutes of energy usage is more than they want.
This is clearly incorrect, the battery was preconditioning on the way to the charger. My Wh/mi clearly went up by more than short journey use when I added the charger as a destination and the display also told me it was preconditioning the battery.
That's doesn't mean the battery heater is on. Here's a trip where the preconditioning message was on for the whole trip:
Interestingly the state of charge doesn't drop dramatically when the heater is on.
That graph appears to show it preconditioning below 20%, or am I interpreting in wrong?
That's from TeslaMate log. It's a self hosted data log.
MyTeslaMate
MyTeslaMate is a data logger for your Tesla, it will record all the information sent by your car: Charge, Trips, Sleep, Update … and present it to you with many statistics and beautiful graphics.
www.myteslamate.com
