Different strokes - for me, I think there will be less hassle in plugging it in each night because it will become a habit, rather than the hassle of needing to remember which nights I need a charge and which I don't. I don't think either way is harmful.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Is leaving Tesla plugged in while not charging really beneficial?
- Thread starter pepperoni
- Start date
I agree. For me, it is part of my routine and that makes my life easier.
Park car, get out, plug it in. Whenever I need it, it's charged up and ready to go.
I suspect that anyone who is calling plugging in every night a "hassle":
1. Does not have the EVSE close to the car and
2. Does not use a WC
If you actually do have a WC near the car, it's just as easy to plug in as it is to close the car door.
Undecided_2
Member
The original OP wanted to know why the Tesla manual states to plug in while not used. Long term owners pointed out that part of the manual hasn’t been updated in 10-years. The OP can plug in at work easily and at home. As usual it went off topic and I’m guilty of helping…
Personally, I plug in every time as the WC is in the garage where I leave the car as it’s convenient. I don’t know if I care enough to find out why Tesla state to leave it plugged in all the time it’s not being used.
buddhafree
2022 MYP
I'm using home automation server to monitor Tesla Wall Connector power usage. Based on my observations, it only uses AC power in the following cases:
- To charge the battery when SOC level falls bellow set charge limit (2% delta)
- If someone enters the car then it uses Wall Charger to power electronics(computer etc.) and for climate control
- To warm/cool interior and to warm up the battery before departure or when climate control is turned on in the Tesla app.
The benefits of leaving the car plugged in are
- To insure that SoC won't fall bellow min 50% or whatever level is set by the user
- To allow the car to warm up the battery and to cool/heat the interior without reducing SoC before departure
- To use the car computer while parked without affecting SoC
- To charge the battery when SOC level falls bellow set charge limit (2% delta)
- If someone enters the car then it uses Wall Charger to power electronics(computer etc.) and for climate control
- To warm/cool interior and to warm up the battery before departure or when climate control is turned on in the Tesla app.
The benefits of leaving the car plugged in are
- To insure that SoC won't fall bellow min 50% or whatever level is set by the user
- To allow the car to warm up the battery and to cool/heat the interior without reducing SoC before departure
- To use the car computer while parked without affecting SoC
mangrove79
Member
I follow Tesla's guidelines in terms of charging percentage (low of 40% and high of 90%), but not the keep the car plugged in every day even when not driving. I just don't like the idea of doing tiny charges of 5, 10, 20 miles on days I don't drive much. Or on a 4-day out-of-town trip the phantom drain will cause the car to do a 1 or 2% charge. I know Li-ion batteries don't have memories on paper, but in the long run, battery degradation does happen and perhaps these tiny charges will have a cumulative effect. I charge on average every 4-5 days or whenever the SoC is below 40%.
I also have the habit of taking the charger off the port soon after the charging completes. Looking at my electricity provider's dashboard I do see higher usage if I keep the charger plugged in (but not charging) than with the charger unplugged. Not scientific by any means but seems tangible.
I also have the habit of taking the charger off the port soon after the charging completes. Looking at my electricity provider's dashboard I do see higher usage if I keep the charger plugged in (but not charging) than with the charger unplugged. Not scientific by any means but seems tangible.
buddhafree
2022 MYP
The battery ideal SoC appears to be around 50%. If you want to prevent incremental charges every time it goes down 2% then charge the battery to, let's say, 65% and when it finishes charging change the limit to 50%. It won't charge again until SoC drops below 50% which should take days.
The Wall Charger by itself takes only few watts of power to remain on. Any phantom drain in the car will be replenished during next charge anyway.
In the end, it shouldn't meaningfully affect the energy consumption if your car is left plugged-in or not.
I don't think Tesla officially says charge to 90% on a routine basis, especially if it takes you days to get down to 40%. Personally, I never go as high as 90% unless I really need to.
On the charging car menu graphic drawing, Tesla shows a range of 50% to 90% for daily use. I take that to mean, charge up to 90%, if you need that much ... otherwise, stay at the lower end of the range. The lower end must be less degrading on the battery, or the manual would say, always charge to 90%. It doesn't say that. How much difference does it make? Who knows.
My daily commute takes about 20%. I operate in the 60-40% range (unless on a road trip) and keep the car plugged in when it's home. My operating SOC is roughly centered around 50%.
But that's just me.
Last edited:
I used to think the same way, but I realized that any time you drive your car, you're probably charging and discharging dozens of times thanks to regenerative braking. When driving, you're often discharging up to hundreds of kw, and charging back at up to 85 kw. I figure that a few more charges at a few kw probably won't hurt the battery much.
Undecided_2
Member
ucmndd
Well-Known Member
Your feelings on the subject aside, your chosen charging habits (fewer, deeper, discharge cycles) are objectively worse than more frequent smaller cycles.
You should stop if your primary objective is to maximize battery health.
Why is this? Why should less frequent vs more frequent charging make a difference?Reference? I’m genuinely interested.
ucmndd
Well-Known Member
It’s not really frequency, it’s depth of discharge. Good reading and graphs here:
The analogy I hear most often is that charging and discharging a lithium battery is like stretching a rubber band. Bigger stretch = more wear = quicker breakdown of the materials. Stretching a rubber band between 40 and 60% of its max range 1,000 times will damage it far less than stretching it from 0-100% 200 times.
Lithium batteries are happiest at about 50% charge. The more time they spend close to that, the longer they last. There are zero valid battery health reasons for charging the way mangrove79 describes.
Figure 6 on that site actually suggests the optimal charging cycle is 75%-25%, and it's the reason why I once thought it'd be best to not plug in the car too much. Even though shallower cycles give you more cycles, the cycles are so short that total energy delivered is actually less.It’s not really frequency, it’s depth of discharge. Good reading and graphs here:
The analogy I hear most often is that charging and discharging a lithium battery is like stretching a rubber band. Bigger stretch = more wear = quicker breakdown of the materials. Stretching a rubber band between 40 and 60% of its max range 1,000 times will damage it far less than stretching it from 0-100% 200 times.
Lithium batteries are happiest at about 50% charge. The more time they spend close to that, the longer they last. There are zero valid battery health reasons for charging the way mangrove79 describes.
However, I suspect the results apply more to consumer electronics batteries rather than EV batteries. Plus, during normal driving you go through dozens of shallow charge and discharge cycles, and it doesn't seem have much of a negative effect on battery life.
That's not what a "cycle" is. One cycle is 100-0% and back once, or 75-25% and back twice, or 75-65% and back 10 times, etc. A cycle is draining and replenishing the entire capacity of the battery. Another important factor is table 2, which shows that a smaller depth of discharge gives you more cycles. Then there's this, which shows that lower storage SoC is better. Put it all together and you have: charge as frequently as possible and set the charge limit as low as you can get away with.
Undecided_2
Member
I keep mine at 60% SOC (it rarely drops below 35%) but it appears that keeping it at 50% SOC is better for battery health? If I set it to that it would likely drop close to 20% which I thought was bad for the battery?
andaconda
Active Member
I think this subject is just 'over thinking.' I plug it in when the nag pops up on the center screen, then charge to 80%. No sense to wear out the charging contacts. Occasionally I'll drain the battery to 3~4% and then charge up to 100% (of course I drive at least 10% of this OFF as soon as it reaches 100%.) Each to his own. I doubt I'll keep the car long enough to get past the battery warranty.
Undecided_2
Member
I won’t keep the car past the warranty. I’ve an MYP on order so my current MY will be sold/traded when it arrives.
ucmndd
Well-Known Member
This is not a thing.
“Over thinking” is one thing. Making decisions on bad or just made up information is another.
Similar threads
- Poll
