Top Tips for Optimal Battery Health

[Uncle Paul]

Perhaps the biggest take away from this discussion, is that battery degradetion is far less than people though it would be when Tesla first came out.

People thought that after 8 years the batteries would be worthless, but that has not turned out to be the case.

For the most part, battery life has turned out to be much less of an issue than was originally thought.

 

[MaDProFF]

There are quite a few older cars out there with 100k - 300k miles, and all are reported back to be like 10% degradation. I assume though none that are 8 yr old so far, but agree people seem to think that golden number batteries will just die and stop dead.

 

[ME_UK]

I have a 70 mile round trip for my commute and planning on charging to 80% overnight and when waking up changing the charge to 90% to warm the battery up and also to get a bit more range as I know there is going to be allot of battery loss as the colder weather kicks in.

This will be for an SR+. Does this seem like a good plan?

I have an SR+, and a 90-100 mile commute (depending on the route I take). I'm still trying to 'play' with the optimum range/charge/timing - but have so far found that setting the charge limit to 90%, and the timing so it's finishing charging just as I get in works well.

Although recently I've had a couple of journeys where preheating the car for 20 minutes before I need it, which impacts charging so I leave at around 88% (in a toasty warm car) has given me some efficiency benefit.

This morning I got 96% efficiency on the drive without really trying, at an avg 10 degrees - 21% of battery for 46 miles.

Teslafi helps track all this - and I tend to have other drives to do after work due to the typical kid run cycle too, so I like to get home with a little more in the 'tank' just in case.

That said, we do charge up to 100% for longer journeys as we need to, and I do vary the charge a little down to 80% if I know I'm not going to be using it much, and also aim to run it down into the low teens once a month.

Geeky post - I apologise. In short your plan looks great

 

[elecTED]

My charging level? 88

Are you using something other than the official Tesla app to set it to exactly 88%?

The battery charging graphic in the Tesla app has some markers to indicate 50/60/70/80/90%. Below is 80%.

Would be nice if the app gave an exact % as you slide the arrow marker back and forth.

 

[MrBadger]

I wish app or car was better. I use TeslaFi to set mine to more exact values.

 

[LukeT]

Are you using something other than the official Tesla app to set it to exactly 88%?

The battery charging graphic in the Tesla app has some markers to indicate 50/60/70/80/90%. Below is 80%.

View attachment 468402

Would be nice if the app gave an exact % as you slide the arrow marker back and forth.

Why the desire for exactly 88? Stay away from the Back to the Future VHS...

One point twenty one Jiggawatts, Marty!

 

[SirRob]

It continues to baffle me why so many people feel the need to fiddle and tweak with things. I trust Tesla far more than any attempts by armchair scientists - if the Tesla app gives you an acceptable range for daily driving why not just use that? If you do genuinely know better, pop your CV in.

 

[elecTED]

Why the desire for exactly 88?

My point too!

There are so many variables and factors at play with battery charging so it’s understandable that Tesla are unable to provide hard and fast rules for maintaining battery health. Everyone uses their Tesla in a slightly different way so something that may be optimal for one user may not be for another.

So perhaps some best practise are:

1. Avoid 0-100% battery charging on a regular basis

I think the point about the min 20 to max 80% battery charging range is that it’s just a guideline that will help to keep the battery in better health over the longer term. If you use 30-90, 20-90, 30-70 or some other number in between it probably makes little difference. Just avoid charging 0-100 on a regular basis it seems. If you want to charge between 21-88, fine

2. Keep charging cable connected whenever possible

Tesla give some reasons for doing this but I personally do see this one as an additional inconvenience as well having an unsightly cable connected to the car pretty much all the time.

3. Frequent Supercharging can decrease charge rates

Does this mean charging the battery at slower rates (if your car usage allows this) is better for longer term battery health?

 

[electracity]

It continues to baffle me why so many people feel the need to fiddle and tweak with things. I trust Tesla far more than any attempts by armchair scientists - if the Tesla app gives you an acceptable range for daily driving why not just use that? If you do genuinely know better, pop your CV in.

Tesla doesn't give optimal technical advice. They give optimal marketing advice. Batteries are complicated and EVs need to be simple.

But charging to 90% and not worrying about it is a perfectly good strategy, especially for the typical buyer who gets a new car every five years or so. Most people who fiddle with charging are interested in the technology and enjoy optimizing the car for their specific needs.

 

[SirRob]

Tesla doesn't give optimal technical advice. They give optimal marketing advice. Batteries are complicated and EVs need to be simple.

But charging to 90% and not worrying about it is a perfectly good strategy, especially for the typical buyer who gets a new car every five years or so. Most people who fiddle with charging are interested in the technology and enjoy optimizing the car for their specific needs.

I wouldn't expect Tesla to give any driver technical advice about the intricacies of the battery technology, I'd expect that to be baked into the logic of the car. In much the same way as I trust the logic inside of the automatic gearbox of my other car to change gear at the optimal point.

If moving a slider from 90% down to 88% does it for you then, more power to you I suppose - but I don't believe for a second that you're capable of achieving more with a mobile phone app than Tesla can with their R&D. Seems like a fairly epic waste of energy (hoho) to me.

 

[dhrivnak]

At least in the Roadster unless you charge above 82% the batteries will never balance. The electronics can only see differences in voltage at very high or very low states of charge. So I charge to 90% which is the number Elon has thrown out and confirmed by our local Ranger. After 29,000 the battery still charges to 284 at a 90% charge.

 

[321filip]

Interesting read about cathodes degradation and capacity loss of NCA batteries

https://pubs.acs.org/doi/full/10.1021/acsenergylett.9b00733

 

[MrBadger]

Some debate on main Model 3 thread about whether it is wise to charge a 'frozen' battery.

MASTER THREAD: Winter driving advice, winter tire choices, etc.

 

[LukeT]

Some debate on main Model 3 thread about whether it is wise to charge a 'frozen' battery.

MASTER THREAD: Winter driving advice, winter tire choices, etc.

How cold are we talking here? Is the (southern half of the) UK cold enough for this effect to be an issue? I find in our winters a car reading down to about - 4 is pretty common but much colder is uncommon. Plenty of north America where well under - 10 would be common.

 

[jollie89]

I once saw a chart showing battery stress at different SoC for different temperatures. Can't find it for the life of me now - can anyone hook me up?

 

[ME_UK]

2. Keep charging cable connected whenever possible

Tesla give some reasons for doing this but I personally do see this one as an additional inconvenience as well having an unsightly cable connected to the car pretty much all the time.

Keeping the cable plugged in helps with security too (so they told me when I collected the car) - it's something else to worry about and doesn't just 'pull out'. Not sure about it, but seemed sensible....

 

[arg]

Some debate on main Model 3 thread about whether it is wise to charge a 'frozen' battery.

MASTER THREAD: Winter driving advice, winter tire choices, etc.

Discussion there seems to ignore the fact that the car won't charge when very cold and will run the battery heating before it will let you charge.

 

[elecTED]

2. Keep charging cable connected whenever possible

Tesla give some reasons for doing this but I personally do see this one as an additional inconvenience as well having an unsightly cable connected to the car pretty much all the time.

Still don’t quite get this one. You’ve charged to 80 or 90%. You will not be using the car for two weeks. If the car needs to do periodic tests, battery warm up parties, wake ups or electron parties why not just use the plentiful juice in the batteries? I see battery depletion of 1 or 2 miles per day when the car is unplugged and not used. Why the need to constantly trickle feed juice from the grid and keep it topped up at 80 or 90%?

 

[electracity]

Still don’t quite get this one. You’ve charged to 80 or 90%. You will not be using the car for two weeks. If the car needs to do periodic tests, battery warm up parties, wake ups or electron parties why not just use the plentiful juice in the batteries? I see battery depletion of 1 or 2 miles per day when the car is unplugged and not used. Why the need to constantly trickle feed juice from the grid and keep it topped up at 80 or 90%?

Why would you not keep the car plugged in when not using it for a few weeks? For storage plugged in and a SOC closer to 50% is probably ideal. In the olden days there was a guy who left his Roadster unplugged in storage and trashed the battery. Stuff happens and you can't be absolutely certain when you will return to the car.

 

[Jason71]

Why would you not keep the car plugged in when not using it for a few weeks? For storage plugged in and a SOC closer to 50% is probably ideal. In the olden days there was a guy who left his Roadster unplugged in storage and trashed the battery. Stuff happens and you can't be absolutely certain when you will return to the car.

Well one very good reason would be while on holiday in which case the car may be in an airport carpark with no option to keep it connected. For the vast majority of people being on holiday is probably the only time they don't use their car for an extended period and being unable to charge during that period is probably also very common. Even if left at home not everyone has the ability to charge at home.