Plugged in or not plugged in?

[flixden]

I know Tesla recommends keeping the car plugged in when not using it.

But I am wondering: WHY?
Does it benefit battery longevity and capacity (less degradation?) in any way to keep the the car plugged in, vs. having it disconnected?

In my case, I prefer disconnecting after I am done charging, and / or when I am on vacation or on a business trip, not needing the car.
The reason in my case are very frequent power outages (sometimes for seconds only) where I live. I am somewhat concerned about power surges doing damage during these outages of power flickers.

So ... should I always keep the car plugged in? Why is Tesla recommending that?

 

[Silicon Desert]

so many threads about this. Have you used the search function?

 

[tga]

But I am wondering: WHY?

To minimize support headaches.

 

[Rocky_H]

But I am wondering: WHY?

So ... should I always keep the car plugged in? Why is Tesla recommending that?

They are trying to sell cars.
They are trying to build good consumer habits.
They are trying to keep it simple and normalize EVs as an easy to use consumer product.

There are kind of two parts to this. There was some old nonsense scary stories that some of the public had heard and believed that electric cars would continually be force fed electricity and overcharge and explode!!!1!1!! It's bulls#i&, but I have seriously seen people here on this forum terrified of that, thinking they needed to go running to their garages to pull the plug before the car blew up. So Tesla was trying to fight that misinformation to let people know they could plug it in whenever they wanted and leave it as long as they wanted with no worries.

The second part is that they didn't want to encourage people to intentionally run their cars down really low, and then they might forget to plug in when they really needed to, and they would get up in the morning, and the car didn't have enough range to drive to work, and then they would get angry and tell all their friends that EVs are stupid unusable pieces of trash and to avoid them.

So that advice to plug in as often as you want and leave it is just to keep things simple and convenient.

 

[flai54]

I know Tesla recommends keeping the car plugged in when not using it.

But I am wondering: WHY?
Does it benefit battery longevity and capacity (less degradation?) in any way to keep the the car plugged in, vs. having it disconnected?

In my case, I prefer disconnecting after I am done charging, and / or when I am on vacation or on a business trip, not needing the car.
The reason in my case are very frequent power outages (sometimes for seconds only) where I live. I am somewhat concerned about power surges doing damage during these outages of power flickers.

So ... should I always keep the car plugged in? Why is Tesla recommending that?

I don't always keep my car plugged in until I need to charge it. Like you, I only keep it plugged in only to charge and remove when I am done. Like others have said, the recommendation to always keep the car plugged in is to establish good charging habits especially for those that are transitioning from ICE cars where you realize that you have to "fuel up" or recharge in this case more often than you do with an ICE car.

But I mean its not like if you don't keep your car plugged in that it will stop working. I would just do what you do and if you are going to be leaving your car at home during vacations, just make your battery is charged to 70-80% before you leave and turn off things like sentry mode so it doesn't cause any additional battery drain.

 

[rlsd]

I prefer to have at least 200 miles on the car for couple reasons: power outage,
earthquake or fire evacuation, medical emergency to family members, out of town friends and family members call for gatherings.

 

[ElectricAnt54]

Keeping it plugged in lets car precondition as needed without depleting energy from battery. I’m leaving mine plugged in more often now. I also tend to set my charge limit to 50% (I do not have LFP battery) since I do not drive far often during the weekdays, a perk of living in the center of a large city. On Friday night I charge up to 80% ( I do not have LFP battery).

keeping car plugged in allows 12v battery to get recharged while maintaining high voltage battery state of charge.

same benefit if you have sentry mode on or use the cabin overheat features while car is parked At home.

 

[Resist]

I always keep it plugged in while at home. Obviously I can't do that while on a trip or not at home. But there is no reason not to keep it plugged in at home, for all the reasons others have explained as it's just better for the car.

 

[Pianewman]

Resist: Agreed. While at home, during thunderstorm season, I always unplug the EVSE when thunderstorms are present. Ditto, if I'm away for extended periods, I leave the car between 50-60%, asleep.

 

[flixden]

I always keep it plugged in while at home. Obviously I can't do that while on a trip or not at home. But there is no reason not to keep it plugged in at home, for all the reasons others have explained as it's just better for the car.

Why is it better for the car? Could you explain?

 

[gtae07]

I just plug in when I get home at the end of the day and it stays plugged in until I leave. I may come back in the middle of the day and I won't plug in then, but I know I'll be heading back out soon enough. Figure there's no point wearing out the charge port and cable when it's peak rates and I won't be charging anyway...

 

[Resist]

Why is it better for the car? Could you explain?

Others in this thread already explained it. But okay, Tesla recommends it because it keeps the battery at your designated percent of charge, because if it isn't plugged in you will lose battery power which is normal for all rechargeable batteries. And you'll lose even more if Sentry Mode is enabled. Also, it keeps the 12 volt battery charged without losing battery pack power. All this is important if you don't drive the car everyday. And there are times when say late at night you decide that you want to take a spur of the moment trip the next day, imagine you are already in bed and if the car is plugged in then all you have to do is set the charge limit via the app for your trip. If it wasn't plugged in then you'd have to get out of bed and go out to the garage.

For me, it's an automatic thing to plug the car in when I get home so the next time I get in it I know it has the charge that I want and is ready to go. Easy peasy!

 

[ElectricAnt54]

Why is it better for the car? Could you explain?

Plugged in or not plugged in?

I know Tesla recommends keeping the car plugged in when not using it. But I am wondering: WHY? Does it benefit battery longevity and capacity (less degradation?) in any way to keep the the car plugged in, vs. having it disconnected? In my case, I prefer disconnecting after I am done charging...

teslamotorsclub.com

FYI @flixden

 

[flixden]

Plugged in or not plugged in?

I know Tesla recommends keeping the car plugged in when not using it. But I am wondering: WHY? Does it benefit battery longevity and capacity (less degradation?) in any way to keep the the car plugged in, vs. having it disconnected? In my case, I prefer disconnecting after I am done charging...

teslamotorsclub.com

FYI @flixden

Hey Electric! Thanks for replying again.
I am just not seeing a very strong argument in your response, or resits response.
But in the end, I feel my question was answered. Thanks again for participating!

 

[Resist]

I have left my car unplugged in my garage for weeks at a time, but all that does is allow the battery to slowly drain. If you have time to charge up before you need to drive your car then that works for you. But if your car has the lead acid 12 volt battery which have been prone to early failure, you might want to keep it plugged in. Mostly though keeping it plugged in is for the convenience of charging it if you need to and aren't near the car.

 

[E90alex]

It’s mostly for convenience and ease of use and to get people into the habit of plugging it in daily. Plug it in when you get home, unplug it when you leave. Obviously if you’re coming home for 15 mins and heading right back out then there’s no use in plugging it in then.

If you prefer to unplug it for whatever reason then that’s up to you. There is no harm in being physically unplugged. The only thing is potentially increased calendar aging if you charge it up first and then unplug it and let it sit all night at the higher charge level. You can mitigate that by plugging in early in the morning.

But plenty people have TOU electricity rates and it’s much easier to just leave it plugged in when arriving home and set it to start or finish charge at the proper time instead of having to remember to plug and unplug it.

In terms of battery health, it’s better to have smaller depth of discharge and to finish charging right before you need the car. So that means charging daily and finishing charge right before you leave for the morning. I’m not waking up extra early just to plug my car in or worrying about what time I need to plug in based on current charge % in order to have it finish by the time I leave. I set it to finish by 9 am and leave it plugged in all night and it figures out when it needs to start.

If you use the climate preconditioning feature, then it’s more efficient to draw from the house for that instead of the battery.

For people that rarely drive the car, it prevents potential phantom drains from completely draining the HV battery.

For people that park outside, it lets them keep sentry mode running without draining the battery.

 

[tga]

if it isn't plugged in you will lose battery power which is normal for all rechargeable batteries.

You lose battery power because of standby loads in the car, not because of self-discharge (which seems to be what you're implying).

But if your car has the lead acid 12 volt battery which have been prone to early failure, you might want to keep it plugged in.

The 12V battery cycling is unchanged whether the car is plugged in or not, whether you have a lead acid or Li-ion 12V. The car does not continuously float charge the 12V (or HV) batteries when plugged in. That would require a continuous AC supply to the car, which doesn't happen. The contactor in the EVSE/WC shuts off when the main pack is finished charging and only turns back on when the car needs AC power (HV charging, HVAC, maybe 12V charging or other activation of the DC-DC; not sure on that one).

This is easy to prove to yourself. Go to your EVSE/WC in the morning after charging overnight. You'll see that there is no power flowing to the car (unless you caught it preconditioning, etc). Turn on the HVAC and you'll heard the contactor clunk and see power start flowing.

@Rocky_H's post above is right. There may be trivial improvements to battery life leaving the car plugged in, but it's really about normalizing EV's, simplifying the rules for the average non-technical consumer, and minimizing the load on Tesla Support. Leave it plugged in if you can, if only for convenience. Or don't. In the end, it just doesn't really matter all that much.

 

[davewill]

Any charging regimen that has the battery at the charge level you want when you drive will work. For me, that's plugged in whenever home, car set to charge to 60% and timer set for overnight during super off-peak. This way, I can override either the timer or the 60% charge level from the phone any time I perceive a different need. Also, if I were to try to sometimes leave it unplugged, I would constantly forget to plug it in at all, so this works for me.

If plugging it in once a week and charging to 80% works for someone else, there's nothing really wrong with that, so long as the battery charge level works for their driving needs.

Note: I am not even trying to address battery health issues. There are ENDLESS threads on the site, with more graphs and strongly held opinions than you can shake a stick at. If you want to go down that rabbit hole, you should consult one of those threads.

 

[Tom Sagrak]

Personally, I'm too lazy to plug it in if there is no need....
For example I have now 41% and do not plan to go to any trips besides my usual work day 10-20 miles. On Friday I will charge to 60% since we plan a short trip.
I do not think it would be better to go to SoC 50% every day.
Anyone in the situation as myself?

 

[easyev]

Keep it plugged in. It will utilize your household power to precondition battery preheat, and pre-cool. Plus it’ll also be charged up to max and ready to go for any last-minute trips, and as others have mentioned, emergencies.

I did this with my 2015 P85DL model S and after 100,000 km range only depleted 3.7%.
Almost new performance after 8 years.