Battery conditioning, is it worth it?

[neeonline]

Doesnt work that way. Remember its Miles PER Kwh (in your words "spent"). Not KWH spent per Mile.

So you are not spending 2 normally. You are Spending 1 kwh and getting 2 miles, so over 25 miles you are spending 12.5 kwh. When not preconditioning you are spending 1 kwh and getting 1.4, so over 25 miles you are spending 17.8.

Thanks. So preconditioning a Lightning is a waste of money. Good to know. Will start to pre-heat the cabin instead.

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[luebri]

Thanks. So preconditioning a Lightning is a waste of money. Good to know. Will start to pre-heat the cabin instead.

If you are confident your spend is truly 8kwh then yes in your scenario it does not make sense. Unless the automatic schedule of the cabin being warm is worth it. (For me it is, because my electricity is extremely cheap at that time)

Also you could reduce your 8kwh Precondition "spend" if you time your charging to be immediately prior to our precondition time.

See attached example. My charging started at 3 am to 4am (paused for an hour based on my schedule) and then started again at 5am finishing at ~6:10. Since my battery was warm from the charging my precondition "spend" was only 3.2 at max (Since this graph show whole home use) between 6:30 and 7 (7am Departure). Probably more like 2.0 to 2.5 if you back out typical house usage at that time.

 

[TaxmanHog]

My "commute" is a about 5 miles to the office so I am doubting the efficiency gained from a conditioned battery is greater than the electricity consumed to do that conditioning, at least for a 5 mile drive. Today I average 1.7m/kwh on the trip. I doubt that would be much worse on a cold battery.

My retired life weekly driving is about the same as your commuting, so once a week charging is my most efficient method, assuming you're not in need of 100% motor energy at your fingertips, this should be good for you.

While remaining unplugged the entire week and remote climate start, cabin is warmed and least amount of shore energy is used, I'll have to pay that back at the end of the week.

If you stay plugged in overnight, then use remote climate start instead of departure timer to suppress excessive battery warming, only in the worst of cold conditions then BMS will draw 1.5 to 2.5 kWh of energy to keep the pack at 100% output, that modest amount might not last the full day.

For folks with longer commutes and colder conditions, the early morning charge might be good enough.

For really long journeys in extreme conditions, I will stack up all the options, charge to 95%, departure timer with cabin prep scheduled for 10 minutes ahead of actual roll out time, the trucks BMS will decide if/when to prepare the battery, could be 30 to 90 minutes prior to roll out.

 

[Firn]

As long as it's plugged in the truck will keep the battery within it's comfort zone. No need to precondition for battery health.

@TaxmanHog will have to correct me if I'm wrong but I thought he only observed battery heating to maintain temp if you had it set for departure times. Without those the battery was just allowed to get cold.

 

[TaxmanHog]

@TaxmanHog will have to correct me if I'm wrong but I thought he only observed battery heating to maintain temp if you had it set for departure times. Without those the battery was just allowed to get cold.

I've observed (documented in another thread

Intentional cold soak -15 ) that the BMS will spontaneously call for energy without any departure time being set, the truck needs to be plugged into the EVSE that's allowing energy to be available.

 

[Phineas Magliozzi]

Thanks. So preconditioning a Lightning is a waste of money. Good to know. Will start to pre-heat the cabin instead.

For me there is only one use-case for preconditioning, and that is when I know that I'll need all the range I can get, which is rare. Otherwise just the occasional cabin heating before leaving, here in the land of absurdly high electrical rates and relatively mild temperatures.

 

[potato]

@TaxmanHog will have to correct me if I'm wrong but I thought he only observed battery heating to maintain temp if you had it set for departure times. Without those the battery was just allowed to get cold.

Just to further confuse the issue. Mine does what you say and doesn't appear to work like taxman's. I have not yet seen a battery temperature above freezing when I get in the truck. If it's -12 C outside, battery temp is -8 ish. I assume the few degrees difference is leftover heat from charging, which is 11 p.m. - 2 or 3 a.m. usually.

We have some mid -20s coming up over the next few days so maybe I'll see some warming then. But with the "regular" winter cold here I have not seen any evidence of spontaneous warming. Unfortunately I don't have a fancy energy monitoring system to tell me though; I only have the battery temperature via CarScanner (and the instrument cluster, which always shows the temperature on the cold side when it's been cold soaked, even after driving).

More on topic, I agree battery conditioning (departure time) isn't worth it unless I'm embarking on a road trip and need all the range. The seat and steering wheel heat kick in almost immediately so even cabin preheating is no big deal, really.

 

[Ragman]

If you live where it's cold (32F/0C is not cold...) plugging in and preconditioning are needed. I have seen a "Red" battery once at -35 unplugged, I don't recommend this.

If you drive more then 50% of your battery in one shot, preconditioning is needed.

Just simply plugging in at -35 keeps the battery in the "Blue" safe zone, I set our trucks to "departure" time every 12 hours regardless of use. While it may not be energy efficiency, there is a lot of plastic and connectors I figure a "warmish" pack will keep rest of the truck that little bit less brittle...

 

[VTbuckeye]

I used to set my charge window for 9PM to 1PM per my utility EV charging window. Typical usage is 12 to 25 miles daily and when really cold this means 7 to 15kWh added. It would charge from 9 to 11 adding using 14kWh and then around 530 pull another 2ish kWh to warm the battery....only to give that energy away again as the battery cooled. Our Volvo does not seem to do this, but warms the battery at the start of the charge cycle, then starts adding power to the battery (display will show miles added and amp draw). I now charge the Volvo starting at 9PM and the lightning at 330AM. The battery warms some from charging and wastes less energy. In the summer I'll probably go back to 9pm charging.

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