Any best practises for charging

[GeorgeSymonds]

The worlds not perfect. What’s good for the battery may not be good for BMS calibration and while your battery might be healthy, the BMS might be pessimistic.

I keep our car between about 30% (100 miles range) and 80% (270 miles), and only go outside that on trips. I charge once a week, sometimes twice, but we’re relatively low mileage compared to some.

I thinks it’s easier to say what’s bad, always changing to 100% (unless LFP), emptying the battery to zero regularly, leaving the car at either of those extremes for any length of time, rapid charging continually. Most other things the BMS will look after you (manage temperature, limiting power in or out when needed etc).

 

[Sean.]

It will make f all difference if you just charge it and use it. Maybe in 5 years time there might be a difference but who knows?

Typically I charge at 90%. I'm knocking on 70K miles, and almost 5 years with a 100 kWh pack - full range has dropped around 8% over time. Full range at 100% SoC is now around 267 miles. It was around 288 miles when the car was new. The largest drop came after around 12 months, then plateaued, dropped, plateaued again etc.

 

[Pajo78]

Plug it in every night

Any views for folks who are going to be reliant on public networks? Live in an apartment and something that is constantly playing in my mind if it is the right decision to go ahead with this buy as will be reliant on public network. I do read a lot of recommendation on charging daily, however not tenable for users staying in apartments or for those reliant on public charging infrastructure.

 

[Zilla91]

Why?

Why not? I charge my phone every night rather than running the battery down before charging again.

I thought the biggest advantage of having an EV is you wake up every morning with a “full tank”?

 

[yessuz]

Any views for folks who are going to be reliant on public networks? Live in an apartment and something that is constantly playing in my mind if it is the right decision to go ahead with this buy as will be reliant on public network. I do read a lot of recommendation on charging daily, however not tenable for users staying in apartments or for those reliant on public charging infrastructure.

Well it's best practice not the guide to manage...

 

[Adopado]

Why not? I charge my phone every night rather than running the battery down before charging again.

I thought the biggest advantage of having an EV is you wake up every morning with a “full tank”?

I certainly like to have the car plugged in ... even if I'm not expecting to need to charge ... though part of that is because it avoids having to go out to the car (because it's not kept right beside the house). Great to have app control of the heating/preconditioning in cooler months without reducing my battery range. Perhaps some people have such consistent daily vehicle use that they are happy to live with a low SOC but I certainly like to have a good percentage on board. Things "crop up" unexpectedly. I have an older SR+ so there's less leeway! 70 to 80% usually but 90% if I know there is a heavier driving day in the offing. Only the full 100% to balance the BMS a couple of times a year.

 

[prabhu]

Why not? I charge my phone every night rather than running the battery down before charging again.

I thought the biggest advantage of having an EV is you wake up every morning with a “full tank”?

How many years your phone battery lasts before you dump it to get a new one? 3 years? My current phone is over 5 years old and the previous one had a similar span.

 

[Jason71]

Why not? I charge my phone every night rather than running the battery down before charging again.

I thought the biggest advantage of having an EV is you wake up every morning with a “full tank”?

Is that a good argument? You will bin your phone un a couple of years because the battery is shot

 

[Zilla91]

I’d have thought the batteries in a car would fare better than those in a phone.

As for whether it’s a good argument or not, doesn’t matter, what I do is exactly what Tesla recommend you do

 

[SteveJol]

I’d have thought the batteries in a car would fare better than those in a phone.

As for whether it’s a good argument or not, doesn’t matter, what I do is exactly what Tesla recommend you do

Plug it every night is fine, depends what you have the max charge set to, that is the only point of contention.

 

[Zilla91]

Usual 80% that everyone else seems to be doing

 

[DrJFoster]

I think if the battery was that precious and delicate that using it other than optimally could damage it excessively then electric cars are doomed. We're talking small differences in aging really.

 

[ElectricPolice]

I think if the battery was that precious and delicate that using it other than optimally could damage it excessively then electric cars are doomed. We're talking small differences in aging really.

My thoughts exactly. We don’t have enough years of data to conclusively state one way or another or there would be a known consensus we’d all be familiar with by now.
Didn’t Tesla recently say they reckon their batteries are expected to outlive their cars?

 

[SteveJol]

Usual 80% that everyone else seems to be doing

What sort of percent are you using a day? I've heard hovering at 50% is the ideal. I.e. you use say 20% a day, set the max to around 65%, use down to 45 then charge back to 65 each night.

 

[D.E.]

Are there any best practises on charging etc? Should I run it down to 10-20% then charge it back to 90% as needed or should I be charging a small amount each night back to 90%

What's best practises for maintaining good battery health.

Others feel free to chime in. The batteries do best if they oscillate around 50% charge so there’s no need to run it down to 10-20%. Best is to keep it plugged in and limit the charge to 80-90%. If you do run it up to 100% for a trip, try to time the 100% for the time you start the trip, don’t let it sit at 100% any longer than necessary. Still you can charge to 100% for the trip Without undue battery “wear”. It you take reasonable care of your battery it’ll serve you well for the life of the car. You’ll lose a little range in the first year or so then it tends to plateau.

In general don’t worry about the battery, just don’t charge it past 90% unless going on trip where you need the range, and don’t run it down to zero,

 

[Adopado]

What sort of percent are you using a day? I've heard hovering at 50% is the ideal. I.e. you use say 20% a day, set the max to around 65%, use down to 45 then charge back to 65 each night.

You are probably in the right ball park but the difference between that regime and the 80% setting is likely to be very little indeed… yet that could have quite an impact on daily practicality if, like me, you have a smaller battery with a shorter range. I’ll take another half percent degradation to ensure I have a longer range without having to do last minute top ups or increase my use of DC rapid charging with the consequent negative impact that may have … it’s all a balancing act.

 

[Wol747]

FWIW my "S" is 28 months old now and since I have free supercharging I tend to use that when I go shopping near the nearest superchargers (65Km away) - just because (a) I'm mean and (b) I like the coffee from the gas station where it is. I normally set it to 80% which means it's at 70% when I get home and I only plug it in there when it gets below 50% - which is never.
When it was delivered it showed 585Km on 100% SOC: this went up to 607Km in Sept 2020 after an update and is currently back to 586Km.
Make of that what you will!

 

[095179005]

I drive ~15 miles one way to work everyday, and plug it every time I come home.

I set the charge to 50%. Once or twice a month I'll charge up to 90% to calibrate the BMS.

In the winter I charge to 80% to account for the heaters and reduced range.

TL;DR
High SOC is the primary cause of calendar aging.
High environment temperatures will degrade a passively cooled battery - not an issue for Tesla.
Supercharging/DC fast charging is 1-2% worse than Level 2 charging.
Depth of discharge and # of cycles ultimately determines the lifetime of a battery

• Partial full cycles/smaller discharges and recharges mean a longer life for the battery

 

[D.E.]

I drive ~15 miles one way to work everyday, and plug it every time I come home.

I set the charge to 50%. Once or twice a month I'll charge up to 90% to calibrate the BMS.

In the winter I charge to 80% to account for the heaters and reduced range.

TL;DR
High SOC is the primary cause of calendar aging.
High environment temperatures will degrade a passively cooled battery - not an issue for Tesla.
Supercharging/DC fast charging is 1-2% worse than Level 2 charging.
Depth of discharge and # of cycles ultimately determines the lifetime of a battery

• Partial full cycles/smaller discharges and recharges mean a longer life for the battery

Wow, great video. Thanks for posting the link in your message.

 

[WannabeOwner]

I did 95,000 miles over 3.5 years in my first 2015 Model-S - that was the 90 battery which is arguably the worst Tesla has made. Lost 6% range (probably half of that in first 6 months, and as I understand it that is normal for EV batteries to have an initial drop which is not representative of subsequent degradation)

I now have a replacement 2019 Model-S at around 20K miles and showing 3% degradation. Family members also have Model-3 and Model-Y

We have always set the Charge Limit to 90%. The original Model-S was supercharged on 2 days a month, often multiple times on those days. The cars are left plugged in - they don't top-up during the night unless there is enough "drop" to make it worthwhile to actually charge.

Whilst I can believe that 50% is perfect for battery longevity I don't think the difference is big enough to make a measurable difference in real life. Plenty of airport taxis (and back around 2015-2018 when battery tech wasn't as advanced as M3 / MY is now) which did 200K miles, were charged to 100% every night and sat there until morning, and then supercharged frequently during working days too. Even then the degradation was not significantly more.

I only charge to 100% if I am going somewhere - i.e. I leave shortly after the car gets to 100%, although I never sweat-it if I am delayed leaving.

I always charge immediately if I arrive below 20% - rather than waiting for cheap overnight rate. (I also wouldn't use full throttle in that state, but once the battery is getting that low I will be more interesting in getting there - rather than getting there quickly!)

My understanding is that rebalancing of the cells only occurs when charging to 100%, not on running it low. I have had 100% 7kW charges sit at 100% (continuing to charge) for variable amounts of time - often 30 minutes, sometimes more. So additionally I suggest if doing a 100% charge then, if possible, allow it to finish.