I think on my S the numbet is 52f for the pack, below that I will see regen reduction, once the pack gets down to freezing regen is gone till the pack warms.
You will get used to it quickly.
It's different on the Y, definitely not 52F. There isn't a set temp where reduced regen is removed. I've seen my battery packs at 68-74F before the regen is fully removed.
Normal driving doesn't do it. You have to basically race the car....or just set it to navigate to a Supercharger for preconditioning.
Even flooring it multiple times doesn't heat up the battery quickly, unfortunately. Originally I thought it would but according to the SMT app, three (3) 0-60 runs back to back barely made the battery packs nudge up.
I believe that it is sensible not to warm up the battery fully, because it will usually get wormer while you drive. I think that Tesla intentionally warms up the battery only to a certain temperature below optimum to avoid wasting energy.
I don't agree with this. About 12 minutes of pre-conditioning will warm the battery to the equivalent of 35 minutes of driving. This figure will vary based upon how much in-cabin is needed since this will take priority and heat up prior to the battery packs taking the heat.
Here are some numbers when I tested:
9:32 am 65.8F
9:34 am 66.2F
9:37 am 66.7F
9:42 am 69.8F
9:44 am 73.0F
9:46 am 75.2F
9:50 am 79.7F
9:51 am 80.2F
10:00 am 82.0F
Take note of the larger increase around 9:37am-9:44 am. I believe this is the point where my cabin reached the desired temp and more heat was directed to the battery packs.
I've tested without pre-conditioning and after 35 min of driving, I'm seeing a 9F increase. If you reference the numbers above, 9F takes about 12-13 minutes during the pre-conditioning process.
Also, pre-conditioning will also allow for more brake regen energy. This can be a significant increase in range. With my driving being mostly city/urban and speeds below 55 mph, my brake regen is giving me back 34% of my energy. Cut that in half with a cold battery that limits my regen, and you're reducing my effective range by essentially removing 12 kWh from my battery pack.
Other useless info. Each motor takes 3.5 kW while pre-conditioning, so 7.0 kW. The above test cost me about $0.33 ($0.095/kW). The heat on the Y pulls 300 watts, which is quite low compared to the Teslas using the heated filaments and no heat pump (2+ kW). I'll gladly spend the $0.15-$0.30 to warm up the batteries to get the most of brake regen and a happy battery.
Test notes: Ambient was 58F. I'll do more testing when temps are below 30F consistently, which may be in ~ 1-2 months.
TLDR pre-conditioning will heat up the battery packs much faster than driving the vehicle and it will help keep the range levels higher.