Winter charging

[huy2k]

Winter is coming. Is it better to start charging right after a drive while the battery is warm, or schedule charging so it can be done right before leaving to have battery warm and get best regen? Thanks!

 

[Nosken]

If you are home charging or level 2---Ok to wait, since it chargers slower, but leave extra time. But if you are plugged in for the night---best to charge right away, unless the rates are lots higher $. If supercharging, Charge on arrival while everything is warm. A cold soaked battery will have to warm up to charge, and will charge slower initially.

 

[GtiMart]

Charging as you arrive with a warm battery will be faster / spend less energy because there's no need to heat the battery first. However, the battery will cool down afterwards and will be cold in the morning. You might not have any regen, which means you'll use your brakes and lose efficiency on that drive.
If you instead charge so the car's ready in the morning (scheduled charge, scheduled departure etc) you'll spend more energy to warm the battery before the charge actually occurs, but you'll leave home with a warm battery so you'll have good regen.

Your choice!

 

[huy2k]

Charging as you arrive with a warm battery will be faster / spend less energy because there's no need to heat the battery first. However, the battery will cool down afterwards and will be cold in the morning. You might not have any regen, which means you'll use your brakes and lose efficiency on that drive.
If you instead charge so the car's ready in the morning (scheduled charge, scheduled departure etc) you'll spend more energy to warm the battery before the charge actually occurs, but you'll leave home with a warm battery so you'll have good regen.

Your choice!

Would either affect battery degradation? Electricity is cheap where I’m at. I’m worried more for the battery degradation.

 

[GtiMart]

The BMS is excellent at managing everything to limit degradation, in general you have nothing special to do. That's essentially why you don't have regen when the battery is cold, because regen is charging and charging a cold battery with 50+kW would be harsh. The BMS limits charging power depending on battery temperature, and it also limits discharging when the battery is cold. On a very cold day you might wonder where all your power went. It's all normal to protect the battery, and is done automatically.

The only thing you have some control on that affects the longevity of your battery a bit is how full you keep it. Age degradation is the most important aspect, and a full battery degrades faster than an empty one. A hot battery also degrades faster, and a full and hot battery, well, you get the picture.

 

[ucmndd]

For home charging set your schedule to complete close to when you want to leave the next morning. There is little to no "extra" energy used to heat the battery for L2 charging as some people have suggested here unless it's VERY cold (like approaching zero Fahrenheit) and the battery itself is completely cold soaked. On the other hand, the benefits of having a warm battery when you're ready to depart are many.

For supercharging, you pretty much always want to do that when the battery is as warm as possible (i.e. right after finishing a trip as opposed to the next morning).

 

[AAKEE]

Would either affect battery degradation? Electricity is cheap where I’m at. I’m worried more for the battery degradation.

The basics is that low SOC cause less degradation but at low temperatures degradation is low anyway so there is no need to think about that.

I live in a cold climate (-25C / -13F today).

At home I have the car in the garage which keeps about 12C/50F. I charge shortly before the drive to keep the average SOC low over the year.
I have the Tesla WC and charge at max power, 11kW (16Ax 230V three phases).
At winter time this make the battery warm (~20-22C) and the heat can be used by the heat pump to warm the cabin = lower consumption, it is a noticable difference.
Also a warm battery degrades less when cycled.

At another location I can only charge with the UMC at 3kW (13A) outside. At this position I always charge asap when I arrive as otherwise the most part of the energy will be used to heat the battery. In worst case almost 2/3 of the energy is lost to heat the battery.