Supercharging battery health

[sunhead21]

We are planning a 2000 mile round trip on the West Coast in August and of course we will have to use the Supercharger several times along the way.

From the battery's long term health perspective:

- is it better to fully charge to 90% at each stop (and hence fewer supercharging cycles)

- charge to 60% at each stop and hence more supercharging cycles.

Maybe it doesn't matter - but just wanted to see if anyone has done any investigation on this issue.

Thanks for your insight.

 

[Silicon Desert]

Forget about battery health while you are charging and traveling after charging. I would concentrate more on what is more convenient for you. And yes, there has been LOTS of investigation, experience and discussions about this on TMC and other sites.

 

[Silicon Desert]

Oh and as a side note, I have found (as many other people have found) that the car is pretty good about telling you when and how much to charge if your goal is to maximize total trip time since it will typically have you charge at lower percentages and almost never have you charge to the top unless it is absolutely necessary to get you to the next charger. You likely have already discovered that it isn't worth your time to go from 90% to 100% or in some cases even above 85% because the rate of charge drops off significantly. You might as well get back on the road.

 

[KenC]

Charge to whatever level necessary to continue your trip to your next stop. I used ABRP for last Summer's 4400 mile trip planning, and it rec'd an average charge level of 66%, and a high of 82%. As long as you are not leaving your 3 at high SOC levels, it shouldn't have any effect upon your battery's long-term health. My battery is still in its top buffer after 37k miles.

The fastest trip strategy is to drive as fast as you are comfortable with and charge at the lowest SOC levels you are comfortable with, and up to a level that will get you to your next stop. ABRP is highly recommended.

 

[ucmndd]

- is it better to fully charge to 90% at each stop (and hence fewer supercharging cycles)

- charge to 60% at each stop and hence more supercharging cycles.

You are not correctly understanding what a battery cycle is.

In any case - stop when convenient and charge when you want, to whatever level necessary to get you where you want to be. Stop worrying about battery health, just drive, and enjoy the trip.

 

[stopcrazypp]

We are planning a 2000 mile round trip on the West Coast in August and of course we will have to use the Supercharger several times along the way.

From the battery's long term health perspective:

- is it better to fully charge to 90% at each stop (and hence fewer supercharging cycles)

- charge to 60% at each stop and hence more supercharging cycles.

Maybe it doesn't matter - but just wanted to see if anyone has done any investigation on this issue.

Thanks for your insight.

What matters is equivalent full cycles. For example charging battery to 50% two times is equivalent to charging the battery to 100% one time. In fact, by charging in a smaller window (the 50%) it actually is less stressful for the battery than charging a deeper cycle (like 100%), so you typically get more than 1 equivalent full cycle by charging a smaller DOD.

BU-808: How to Prolong Lithium-based Batteries

Intuitively, think for example if you charge the battery 1% before discharging 1 %. Would it make sense that it is the same stress as charging the battery 100% and discharging to 0%? Of course not. So you can't count a low DOD cycle the same as a high DOD cycle.

As others mention however, this isn't something you should stress out over when making a long trip. Rather, optimizing the time takes to charge is something you should focus more on. As the battery's SOC increases, charging speed slows down, so naturally most people avoid charging the battery too high. As others pointed out, the fastest way to make a trip is to drain the battery as low as you are comfortable with and charge it just enough (+ whatever margin) to make the next stop. With this strategy there is no need to "turtle" the car, as usually you want to arrive at the supercharger with a lower SOC in order to maximize charging speed.

 

[Regaj]

Road trips in a Tesla are a joy! Completely agree with those who suggest letting your route and schedule dictate what you do. A single road trip, no matter what you do, isn't going to have a measurable effect on long-term battery health.

That said - since you asked - shallower, more frequent Supercharging stops would have less impact on pack health than less frequent, longer sessions.

But, yeah, just enjoy your trip and don't sweat it. Managing your battery for long-term health is something to consider at home, over long spans of time. Not on an occasional road trip.

 

[Rocky_H]

the car is pretty good about telling you when and how much to charge if your goal is to maximize total trip time since it will typically have you charge at lower percentages and almost never have you charge to the top unless it is absolutely necessary to get you to the next charger.

Oh really??! (Here is my skeptical face.)
The car's trip planner software did exactly the opposite of that, last I saw, and I had not heard that they changed it. Whoever programmed it had the preference set for: fewest stops and all else be damned.

That can make for some really nasty recommendations, and after getting burned by that before on a trip in 2018, I never let it choose my Superchargers to use anymore. If it will pick reasonable ones, that's fine, but I had it tell me to charge all the way up to 100% and then drive to its predicted arrival state at 4% just to skip over a Supercharger in the middle. And it hid the one in the middle off the map, so when I looked to see if I had any better choice, it appeared not. I really hope they have fixed that by now, but I haven't seen that they have.

 

[Big Earl]

We are planning a 2000 mile round trip on the West Coast in August and of course we will have to use the Supercharger several times along the way.

From the battery's long term health perspective:

- is it better to fully charge to 90% at each stop (and hence fewer supercharging cycles)

- charge to 60% at each stop and hence more supercharging cycles.

Maybe it doesn't matter - but just wanted to see if anyone has done any investigation on this issue.

Thanks for your insight.

It doesn't matter. Charge when you need to and enjoy the trip. Charging to a higher state of charge takes longer, but charging to a lower state of charge requires more stops. I lean toward more frequent stops, since I start getting impatient after 15 minutes or so. Find a good balance that works for you and your traveling companions.

 

[Silicon Desert]

Oh really??! (Here is my skeptical face.)
The car's trip planner software did exactly the opposite of that, last I saw, and I had not heard that they changed it. Whoever programmed it had the preference set for: fewest stops and all else be damned.

That can make for some really nasty recommendations, and after getting burned by that before on a trip in 2018, I never let it choose my Superchargers to use anymore. If it will pick reasonable ones, that's fine, but I had it tell me to charge all the way up to 100% and then drive to its predicted arrival state at 4% just to skip over a Supercharger in the middle. And it hid the one in the middle off the map, so when I looked to see if I had any better choice, it appeared not. I really hope they have fixed that by now, but I haven't seen that they have.

Rocky that is interesting info. Perhaps things have changed, I don't know. My comment was based on my last trip 5,000 to Tennessee and back mainly along the route of I80 and 70 and 24. This was in May. I pretty much followed the recommendations where and when to charge. It never had me charge to 100% and perhaps that was because it wasn't needed for me to get to a charger. I noticed it would often skip a SC and get me to charge when it got to roughly 20% and didn't have me need to charge more than about 85% on average. Once I needed to charge to 90% but that was needed to get to the next SC with 12% charge remaining. So bottom line I guess it comes down to the route. Going from home to San Diego down 395, I have about the same experience. For me, it has done a pretty good job of reducing my total trip time by not having me charge to a very high value and hence waiting that time with a lower charge rate.

 

[GtiMart]

I have not appreciated the car's stop planning either when going to Florida this spring (5500km). Enter your destination and then look at available chargers along the way. I would choose the one that made us drive the distance we felt like : 1,5h, 2h etc. You can add that as a waypoint. While the car was charging at that stop, I would choose the next one I felt like stopping at etc... You'll see how much charge you need to get to that next charger, and you leave some buffer. That way you see when there's a desert and you pick where it works best for you. I also favored more, shorter stops which just happens to fit with our bladder resistance

 

[AAKEE]

We are planning a 2000 mile round trip on the West Coast in August and of course we will have to use the Supercharger several times along the way.

From the battery's long term health perspective:

- is it better to fully charge to 90% at each stop (and hence fewer supercharging cycles)

- charge to 60% at each stop and hence more supercharging cycles.

Maybe it doesn't matter - but just wanted to see if anyone has done any investigation on this issue.

Thanks for your insight.

You probably already did the drive but…
Most people have already nailed the important part: Just do it, dont worry.

Supercharging a preheated battery does not cause that much wear. It causes more wear than slow charhing but it do not kill the battery.

For the technical part:
- Smaller cycles cause less wear. (Per Full Equivalent Cycles / miles driven).
- The lower the SOC is during the cycle, the lower the wear. For example did 10% depth of discharge cycles around 30% SOC (35-25%) only cause about 1/4 as much wear as 10% DoD cycles around 70%, during a resarch with NCA-chemistry.

Keeping the cycles small (charge often) with as low SOC as you can do without feeling worried about the range will reduce the wear on the battery.

I “save” the battery by having low SOC daily, to reduce the calendar aging but it also reduces cyclic aging.

For trips/travel, I charge to 100% whenever needed without any worries. I also Supercharge during trips when traveling and then I let the navigator decide what I need and where to charge. I always preheat completely when possible. Of the total kWh/miles driven about 18-20% is Supercharged. 45K km now, almost 30K miles and my cars battery is amoung the cars with the lowest degradation.

Having the car charged to 80% everyday, standing all nights with 80% will cause more wear (calendar aging) than supercharging when you need for traveling.

 

[BigNick]

Supercharging a preheated battery does not cause that much wear. It causes more wear than slow charhing but it do not kill the battery.

Some earlier Model S packs, especially the 90 kWh "V1" pack, did get killed by Supercharging. But by the time the Model 3 was being produced, Tesla was no longer making those packs.

 

[sunhead21]

Hi all:

As a followup, we did the 2800 mile West Coast trip in our Model 3 and I used the Supercharger every day to charge up to 80 - 90% every day. I would charge every morning while having our coffee and get back on the road. Top off further during lunch stop. We got it down to a routine. My wife had range anxiety first few days but her worries eased as she saw the Supercharger stations along the route.

Just like everyone said, it was a joy to drive Tesla up and down the West Coast. Thanks again everyone. This was a memorable trip.

 

[Gasaraki]

Shorter charges. Your "cycle" doesn't change. If you charge to 50% one stop and then charge to 50% in the next stop, it is still one "cycle". Same as charging to 100% all at once. However charging to 100% MIGHT lower the battery life if you do it all the time.