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Is 120v enough to precondition battery in Winter?
- Thread starter yogi799
- Start date
12A@120V=1.4kW for everyone. Factor in the power the car needs to run the computer and pumps and charging losses and there's certainly no more than 1.2kW left to charge. km/h is not a great charging concept... it will ultimately depend on the car you have because it uses the Wh you consume for a kilometer to tell you how fast you charge. Another car on the same circuit might report a different km/h charging rate even though it has the same kW power input.
So I went with what seems to be a fact, that 120v is useless for heating the cabin and preconditioning, almost as if the car was unplugged. I mean i use space heaters in my house at 120v and they put out pretty good heat to warm up an entire room but then... the room is not -5 C as the car's cabin would be in Ontario in winter. So, I pulled the trigger and pulled 240v to garage and now have 2 WC's pumping 32A into my M3 (48 amps available). Decided 120v was a waste of time and completely useless. 6 AWG Wire cost me 220 CAD (45ft) and pvc tubing another 120, some other misc connectors and boxes, all together about 400 CAD. Cost i was trying to avoid but now i can sleep well knowing that at -20 in Jan and Feb the car will be happy and getting all the juice it needs from a proper 60Amp circuit.
Soul Surfer
Cancervivor, tech geek & musician
I did my own test this weekend. In 8 hours of charging at 0 degrees with a battery that was initially warm I added 37km or range which is about 9.25% or 7.9kWh of energy. The Tesla app reported that I was charging at 12A and 110V. So I put in 10.6 kWh (12x110/1000*8) and the battery charged by 7.9kWh. So the battery received about 74% of the power, if the numbers reported by the app are correct.
Interesting. Yes, the 120v is truly useless, only good for emergency charging where you know you will need those 5-10 extra kilometers to make it home. WHICH IS exactly what happened to me last week. Made a critical mistake to leave my newly acquired mobile charger at home... and almost screwed myself royally and had to spend 40 minutes extra on the road in an extreme winter blizzard (scary as hell and i love driving... ) to go completely wrong way to the nearest SC. Hd i had the mobile charger with me, i would have added 20 extra km in 4 hours of charge (or so) where i was staying before my trip back home and that would have saved my a$$. Glad i didn't get stuck in the wintry conditions. Scary as hell with an EV to run out of juice. But for normal charging.. or pre-conditioning, looks like 120v is insignificant. Wow. 8 hrs = 37 km or range. Dang. We get that in 1 hr with L2 WC. Good calculations though.
bradtem
Robocar consultant
You should be clear... 120v is far from useless in cool and warm weather, but can present issues in freezing weather if you don't plug in when you arrive while your battery is warm. If you do that it remains useful even in the cold
My Tesla L1/L2 mobile charger stays in the car at all times and I use inexpensive generic L1 and L1/L2 chargers as stationary chargers at our condo and at our winter home. In our winter home, we have 12-2 wiring and 20amp 120v breakers in our garage, and I changed a NEMA 5-15 GFCI for a NEMA 5-20 and now I charge at ~115v/16amps which is a nice boost for 5mins of my time and a few bucks for the NEMA 5-20 outlet. At some point I'll add a NEMA 6-20 outlet and 20amp 240v breaker, but for now the 5-20 gives me about 2.5% SOC increase per hour on my 2022 M3 RWD.
If you are visiting someone for a couple of days then it is useful to give you a bit of a charge - enough to get you to a SC where you can charge much more quickly.
My experience in -25 C in Calgary this week is a 120 V plug will be used for near 100% battery warming / pre-conditioning only, but will maintain SOC only. No charge gains possible.
bradtem
Robocar consultant
What if you plug in upon arrival as many of us do, with the battery warm from driving? Yes, you have to use peak-time electricity but in the dead of winter that's not usually too bad.
This was right away after a 25 minute drive and it didn’t help. For me it’s not important as I’ve got Level 2 and heated parking in 2 places around town the car mostly lives at but was a good experiment to know limits of Level 1 in deep cold.
bradtem
Robocar consultant
Have not had this problem at our place in the mountains, but usually arrive there after 4 hour drive up the mountain so plenty warm. Drives around town are shorter but have worked. If all else fails there are chargers around town.
Hi Folks. First time poster. New to Tesla and bought an old (2015) P85D. Battery is degraded but I don't know by how much. It seems my charge rate, range and top speed are reduced, but that's OK. I live in the mountains of BC and winter temps sometimes hit -35C. No garage.
As I have FUSC and a SC a few blocks away, I don't charge at home, but I want to maintain the battery as best I can. I don't regularly drive locally, but need to drive hundreds of Kms monthly or so.
I have 120V @ 12A, 120V @ 24A available (less convenient), and could install 240V @ 40A. Single rate electricity.
I would plug in the block and a cabin heater in my previous diesel vehicle (RIP) for an hour before departing, worked fine.
Before traveling with the Tesla, I would precondition, head to the SC, top up and warm the cabin (thanx Elon).
Can you folks help me with a strategy to protect my new-to-me baby in the winter, especially overnight?
Thanks
BC John
As I have FUSC and a SC a few blocks away, I don't charge at home, but I want to maintain the battery as best I can. I don't regularly drive locally, but need to drive hundreds of Kms monthly or so.
I have 120V @ 12A, 120V @ 24A available (less convenient), and could install 240V @ 40A. Single rate electricity.
I would plug in the block and a cabin heater in my previous diesel vehicle (RIP) for an hour before departing, worked fine.
Before traveling with the Tesla, I would precondition, head to the SC, top up and warm the cabin (thanx Elon).
Can you folks help me with a strategy to protect my new-to-me baby in the winter, especially overnight?
Thanks
BC John
UncleCreepy
Member
Free Unlimited SuperCharging.
I can't really answer @BC John's question, but if I had FUSC, I probably wouldn't waste money on L1 or L2 charging.
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It's not clear to me what the concern is here. As long as you don't let the charge level get too low, cold temps shouldn't damage the battery. The main reason to warm up the battery is so it can charge, so if you don't want to charge at home, you may not need to warm up the battery.
Thanx for your responses.
I think what I'm hearing is the battery wont be damaged by extreme cold temps when just sitting (for weeks) as long as it's above 20% charged(?).
If I precondition from the battery before driving to the local SC (to top up to 65% or so, or go on a trip), there's no need to plug in at home at all?
If I got that right; very economical, and helps justify my purchase...
I think what I'm hearing is the battery wont be damaged by extreme cold temps when just sitting (for weeks) as long as it's above 20% charged(?).
If I precondition from the battery before driving to the local SC (to top up to 65% or so, or go on a trip), there's no need to plug in at home at all?
If I got that right; very economical, and helps justify my purchase...
ucmndd
Well-Known Member
When it’s that cold, your car will supercharge very slowly. You’ll need to precondition for a very long time to raise the temp of a ~1200 pound cold soaked battery.
Whenever possible, you should change your routine such that you supercharge upon completion of a trip, while the battery is still warm from driving. BEFORE you let the car sit all night. Then in the morning just precondition for long enough to warm the cabin and be on your way.
Whenever possible, you should change your routine such that you supercharge upon completion of a trip, while the battery is still warm from driving. BEFORE you let the car sit all night. Then in the morning just precondition for long enough to warm the cabin and be on your way.
Makes sense, and that's what I have been doing so far. When returning home, I charge up to 70% or so before it sits.
I'm retired (and poor) so I have the time to plan a significant precondition and charge at a SC. No problem walking home if it'll take a while.
There's a free municipal destination charger even closer...
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