Benefit of plugging car in before scheduled charging?

150 deg F and lightning: any benefit of plugging in?

Sorry if this has been discussed before but I can't find it and can't possibly be the only one pondering about this one
Background:
1. I have my car scheduled to start charging every 1 AM.
2. Since the owner's manual says that the car should be plugged in, charging or not, I leave the car plugged in, or plug it in as soon as I come home after driving.
3. Now in the summer we have tremendous thunderstorms almost every afternoon here in Orlando. Appliances go out left and right and my neighbor's house just burnt down. Needless to say I am a bit uncomfortable leaving the car plugged in during these storms, so I unplug when I hear the first bolt of lightning. When it is over I plug it in again.

Question:
is there any benefit to those few hours plugged in while not charging? Or shall I just wait until nighttime? (Some people have suggested that the full thermal conditioning of the battery needs shore power but I can't find anything definite).

PS. This time of the year it is 150 degrees in my garage, so parking with "energy saving" or somehow otherwise restricted battery thermal management doesn't feel like an appealing option.

stevezzzz said:

My understanding is that you should always plug in your S particularly when the environmental conditions are extreme. If you park in your garage after driving and the battery is already warm, and plug it in, the thermal management system will continue to do its best to keep the battery in a safe temperature range. That's only true if your charging circuit supplies 208-240V, though, not 110-120V.

This is only repeating what I've learned on these forums over the years, and should not be taken as the absolute last word on the subject. After all, saying "I read it on the Internet" guarantees precisely nothing.

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Thanks! Sounds similar to what I have read as possible, but not conclusive. Based on this, I should continue doing what I am doing, plugging it in and out possibly several times a day :smile:

Just wondering what would happen in this scenario: You put your Model S up for the summer season in a typical non air conditioned, non insulated Florida garage with the worst case but not uncommon south facing black sheet metal doors. Let's say it gets 250 degrees every day mid day and the car is plugged in to 110 V all summer until you come back for the winter season. If 110 V doesn't properly condition the battery, how will things turn out?

linkster said:

+1 !

might you consider adding 2 upper and 2 lower vents in your garage door and possibly insulating the attic?

(our battery is just too darn expensive not to)

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Exactly! I am spraying the attic with insulation and will also install air conditioning for the garage.

It would still be good to know for sure if I am doing the right thing plugging it in all the time or if there is a setting to let the temp control run properly when unplugged.

linkster said:

dunno either

Since you appear to live near the Lightning Capital of the U.S., you may consider a whole house AND a branch circuit specific surge protector (hopefully an "electromagician" will chime in). No guarantee, but it certainly might help reduce the risk to our S's when the daily summer thunderboomers roll through.

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Yes I have two layers of surge protectors. One pair at the service entrance and one pair at the panel boards in the garage. I haven't seen a branch specific option for 240 V, would be interesting as you say to see if any electromagician :smile: chime in. BTW I installed a heat pump water heater in the garage. It lowered the heat noticeable form previous sauna levels, and lowered my electric bill as well.

Larry Chanin said:

Hi Olle,

It sounds like you are doing the prudent thing.

I live in Sarasota, Florida and my garage door faces south. I guess I'm lucky in that my garage temperature is rarely over 90 degrees. I have whole house surge protection at the main panel in the garage. I follow the prevaling wisdom of plugging in my car whenever possible. I like the idea of providing "shore power" to my car to help condition the battery. I also like the idea of doing frequent shallow charges versus less frequent deep charges.

I figure the constant issue of elevated temperatures in our Florida garages is a sure thing that is affecting our batteries. I reason that the chance of experiencing a close lighting strike that would damage our car, especially with addtional whole house surge protection, is much less likely than the certainty of elevated temperatures.

I've had my car for over 2-1/2 years and I've only lost a few miles in rated range. I believe I'm doing the right thing staying plugged in whenever possible.

Larry

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Hi Larry,
Good for you that it is rarely over 90 in the garage. I came to the conclusion that I need to do something about the temperature in there. Have you found any solid evidence that the battery conditioning works better plugged in?

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David99 said:

I can tell you from experience that the car will keep the battery happy plugged in or not. I usually always plug it in (while using the charge timer). There are many advantages. If you make it a habit to plug in right when you come home, you won't forget to go back out to the car and plug it in later. The car can top off on it's own when needed. You can remote start charging the battery from the app. The car can use grid power if you turn on the AC or heater.

But in terms of battery management, I know from experience that the car will still keep the battery temperature even. I noticed, when parked, my car will run the coolant pump every once in a while to keep the temperature even on all cells. It will do that whether it is plugged in or not. So while there are many advantages to keeping it plugged in all the time, you are not risking battery life when you don't.

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I agree that the cooling operates also when unplugged. What I am trying to find out is if there is anything more than anecdotal evidence that the temp control works better when plugged in?

Larry Chanin said:

Advice Please: Charge Every Night or Not Posing #20

The point of the above referenced data is if you always plug in when the opportunity presents itself it will result in significantly more battery cycles (longer battery life) because the charging cycles are shallower. Deeper charging cycles degrade the battery faster because it puts more stress on the battery.

It also follows (hopefully without the need for extensive data :smile that if you plug in and use your house current to condition the battery in hot weather, then the battery doesn't have to cycle itself to run the air conditioning. If you eliminate unnecessary battery cycling when the car is in your garage you will extend the life of the battery for driving.

Larry

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Makes sense, thanks :smile:

Larry Chanin said:

Yes, like Archie (caddieo) when I am away for a week or more I will keep my car plugged in and I will dial back the charging to about 50%. When storing your car without driving it put less stress on the battery to reduce the voltage on the battery (the voltage on the battery is highest at 100% state of charge).

From Battery University:



You don't want to take this advice too far and store the battery near 0% state of charge because recharging from zero puts more stress on the battery.

Larry

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Good advice, thanks. Today I ordered a minisplit AC for the garage. Will be a relief not to have to think about this heat problem.