Charging to 100% and using DC fast charging frequently

[Flint302]

Each to their own--Personally, I go by what the manual recommends, considering they are the ones who designed and built it.

Sponsored

 

[txfab]

This is right up there with how often should I change my oil on an ice vehicle!. Go by the compute. No, don‘t do that. Every 5,000 miles. No, don’t do that. Every 2,500 miles. No, don’t o that. Go by recommendation in manual. No, don’t do that. Bottom line, it’s your vehicle. Treat it how you want and let the cards fall where they may.

If you're voicing your frustration about getting contradictory information, I hear you.
But as an engineer I know better. If they did the science (which I know they did and do all the time), then there is a "right" answer to the question: does charging to 100% constantly lead to (noticeably, i.e. more than 2 or 3%) quicker degradation, as compared to charging to only 90%.
As to your oil example: there is less of a step function since oil degrades more linearly with usage but it's a great example of listening to a manufacturer whose communication is based in marketing (you should definitely change your oil at least every 5,000 miles OR every 12 months) vs a manufacturer who communicates based on a solid engineering assessment (change your oil after 500 miles the first time, and then don't worry about it for 30K miles, except if you let it get really old, like 4 or 5 years because synthetic oil doesn't really degrade much with just age). So that's actually a very valid debate and not at all dumb: the manufacturers have all subscribed to the idea that their dealers can make a ton of money off services that aren't really necessary from a technical perspective. That makes the dealers happy to sell vehicles at sharper dealer-side discounts, thus driving more profitable sales for the manufacturer. -It's just basic business sense, but at the cost of the consumer.

 

[Tampamike]

The GLI drinks Prem, which hovered around $2.059/L for a long time around when I traded it in. I averaged 8.2L/100km which is actually closer to 30mpg for a cost of $0.17/km * 1.62 = $0.275/mi

My Mach E averages 5km/kWh according to my “fuel” tracking app and lines up with what the in car display says. I pay $0.26/kWh which works out to a hair above $0.05/km * 1.62 = $0.081/mi

Ok, for you that works out.

Here in the states, nobody pays $8.00/gal for gas. Most cars aren’t getting 32mpg either - 25mpg seems like a more common number. I’ve seen a lot of $3.00/gal on a recent road trip. So $3.00/25=$0.12/mile, which makes it more of a wash at the higher EA and even higher EVGo rates.

 

[txfab]

Each to their own--Personally, I go by what the manual recommends, considering they are the ones who designed and built it.

I wish I had less trust issues. IMHO manuals these days are written by the marketing department, with almost no input of "facts" from the engineering department...
(- Now why does that make me think of presidential campaigns all of a sudden..?)

 

[lifebythemile]

Even in that case, going to 100% makes even less sense if you have plenty of options.

Sorry to have created the bee under your bonnet...

To take things out of the completely literal interpretation of what I said previously, do I charge to 100% every time, no. I try to charge to 100% frequently, when and where convenient, which works out to most times I go to charge for my day-to-day driving.

The Ford Manual for the LFP battery (mine, and the OP's battery type) state to charge to 100% at least once per month. If you read the Tesla manual for the LFP battery it states once per week.

If I'm charging during a road-trip I charge based on how much I need to get to the next station +15-20% buffer. If it's the last charging stop of the day I will add 25-30% extra so I pull into the hotel with around 50% (where possible).

 

[superdave80]

The same article then goes on to quote this study from mid 2023
https://insideevs.com/news/683961/fast-charging-vs-slow-charging-study-ev-range-degradation/
which found that frequent DC fast charging actually does not lead to worse degradation than very infrequent use of it.

That study is by a company called Recurrent, and they don't actually measure the battery health, they just look at the estimated range that the computer puts out. And given how Tesla's range estimates are, well, complete trash, this study is worthless. Their 'data' actually shows a few points where DCFC is BETTER for your battery health!

As with any study, garbage in, garbage out.

 

[HuntingPudel]

There is less correlation between charging habits and battery degradation as compared with battery age. They are finding that age has a greater influence on batteries the size of BEV batteries than rate of charge or other charging habits. ??

With regard to Lithium Ion batteries, it still holds true that they hate to dwell at the extremes of State of Charge. Don’t store the batteries at >80% or <20% actual SoC. As @ChasingCoral said, if you’re going to drive a significant distance a short time after reaching 100% indicated, go ahead and charge it up. In my case, work is not far enough away so I don’t do 100% indicated. ??

 

[Sikkun]

Sorry to have created the bee under your bonnet...

To take things out of the completely literal interpretation of what I said previously, do I charge to 100% every time, no. I try to charge to 100% frequently, when and where convenient, which works out to most times I go to charge for my day-to-day driving.

The Ford Manual for the LFP battery (mine, and the OP's battery type) state to charge to 100% at least once per month. If you read the Tesla manual for the LFP battery it states once per week.

If I'm charging during a road-trip I charge based on how much I need to get to the next station +15-20% buffer. If it's the last charging stop of the day I will add 25-30% extra so I pull into the hotel with around 50% (where possible).

Not really a bee under any bonnet….

If someone wants to wait at a DC charger for an extra half hour+ to go 90-100% during a trip when they could charge and drive further in half the time….more power to them.

But I have met people who don’t know about charging curves, or realize 10-80 and 90-100 take similar amounts of time. So they rent an EV and get very pissed off sitting at a charger for 1+ hours because of course you would go to 100%.

 

[lifebythemile]

Not really a bee under any bonnet….

If someone wants to wait at a DC charger for an extra half hour+ to go 90-100% during a trip when they could charge and drive further in half the time….more power to them.

That's not what I'm saying, at all.... In fact I specifically state that is NOT what I do on trips.

When I'm doing my weekly commuting/driving/around-town driving, yes I will frequently charge to 100% to a) maintain battery stats accuracy as advised in the manual and b) I'm usually having dinner or just chilling with a coffee while charging so it's not any extra time out of my day.

 

[Sikkun]

That's not what I'm saying, at all.... In fact I specifically state that is NOT what I do on trips.

When I'm doing my weekly commuting/driving/around-town driving, yes I will frequently charge to 100% to a) maintain battery stats accuracy as advised in the manual and b) I'm usually having dinner or just chilling with a coffee while charging so it's not any extra time out of my day.

I don’t believe anyone has accused you otherwise.

 

[N1naz]

And in some cases, depending on which DCFC station you pull up to, they might charge you a premium after 80%.

 

[txfab]

That study is by a company called Recurrent, and they don't actually measure the battery health, they just look at the estimated range that the computer puts out.

Thanks! Where do you get that from? Did you manage to find the actual study?

 

[4sallypat]

While this has been your experience, Tesla superchargers can in fact be full and have lines.

All depends on where and when.

Especially if it’s a layout where a Mach E is taking multiple spots.

And unless there are 0 other charging options, you are spending double the amount of time going 90-100%, it would be much faster to stop at another charger 200 miles down the road.

Very rarely have I ever seen a Tesla Supercharger full. At one location, I stop at 90% to be polite.

As for the past 6 months charging at Tesla, on a road trip, makes sense as my wife loves to shop at these wonderfully strategic Tesla Superchargers are located.

Waiting 45 minutes for her to finish shopping is priceless....

 

[Sikkun]

Very rarely have I ever seen a Tesla Supercharger full.

I still see plenty that only have 8 stalls and have had to pass to go to other stations. Especially because they can be only half full and pending on layout a Mach E can’t charge.

Even this happens….

Obviously some locations are better than others.

 

[4sallypat]

No guilt charging to 100% as I use the handicap spaces almost every time I charge so that I only take up one space and one charger.

And yes, I have a permanent disability placard.

Sponsored