How often to charge to 100%?

[Athrun88]

Like everyone else, 90% for everyday because I don't know if I'm going to drive 10km or 100km that particular day and 100% if I know I'll be driving more than 150km in any one direction. Full charge usually happens 1-5 times per month. I just happened to accidently charge to 100% yesterday and I'm not losing sleep over it. Use the truck now, any concequences will be up to future me to deal with!

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[chriserx]

I'm likely in the minority with my setup, I have the Ford app set to 100% but through Home Assistant, throttle the charge speed based on charge level making it effectively 70-90% depending on my usage. Instead of having a hard cap where it stops charging at x%, it's literally always charging. Definitely helped out the LVB, haven't had an issue since, all without adding a maintainer.

To answer the question though, 100% for roadtrips 1-2x a month and 2 accidental 100% from lack of driving.

 

[fhteagle]

I go to 100% every time I leave my mesa, which is averaging a little under twice a month. I am seeing small but steady improvement across my 9 months of ownership in:

- time and wall kWh (measured by OpenEVSE) that it takes to go from 99% to 100% indicated
- Carscanner reported kWh available at 100%

I assume the previous owner rarely if ever went to 100%. Not having raw cell V data like I used to have makes this way more guesswork based for me though.

Now the bottom end of the pack, that I still have trouble getting to, trusting, etc. This is the only make/model to strand the Out of Spec crew ... 4 times I think total. And I really cannot come home at crazy low SoC due to a gnarly hill climb right before home + no bailouts available on any route ...

 

[Highpi]

Thanks for all the input, everyone.

It's funny, seeing what Ford actually says appears to be the last place I look. Me just being lazy, I guess.

 

[Chillguy]

My Lightning is my 5th EV in 15 years. I always charge to 100% when I plug in regardless of what anyone says and I plug in twice a week on average despite daily driving. None of vehicles ever experienced degraded battery performance...

 

[SpaceEVDriver]

Now the bottom end of the pack, that I still have trouble getting to, trusting, etc. This is the only make/model to strand the Out of Spec crew ... 4 times I think total. And I really cannot come home at crazy low SoC due to a gnarly hill climb right before home + no bailouts available on any route ...

I regularly climb my 7000 foot mountain with the goal of arriving home with 0% charge so I don’t waste any money on DCFC prices. But I only have a relatively level gravel road for the final 2 miles so I know I can get upward of 8-10 miles/kWh on that section without trying.

 

[vvgogh]

When you charge to 100%, if you measured the energy used, you would find it using more kWh than the battery holds. This is the cells balancing. I have observed more than 10kWh extra. In short, those that always charge to 100% are spending unnecessary money for cell balancing that does nothing for their battery health, and unless they need the range is totally wasted.

I've also seen the > 10 kWh lost during 99-100% cell balancing into resistive loads. So, don't do it everyday. If your battery cells grow too imbalanced, the truck will throw wrench icon with Service Soon warnings and you might need a module replaced. The longer you go without cell balancing, the more a voltage imbalance can grow. So, perform a top-balance periodically. If we do lose 10 kWh into those resistors during a top-balance, performing this once a week costs <$100/y at my rates. I'd aim for weekly - $1k/10y, cheap battery maintenance much cheaper than ICE maintenance.

It's been posted the truck battery management software will balance if it's been unplugged and OFF for 48h. It's unclear how well this works in practice. As you can see from the top-balance's potential 10 kWh energy usage, the truck won't balance to this same level when OFF... the standard range would lose 10% if it did the same amount of balancing.

 

[K6CCC]

According to my charging session spreadsheet, I have charged to 100% 24 times out of 249 charge sessions. All of those were on L2. Almost half of those were allowed to go to 100% because it was free. The rest were at home because I was going to be making a long drive the next day. This is in just over 13 months.
Under normal circumstances, I charge to 85 or 90% at home.

 

[bc1]

I regularly climb my 7000 foot mountain with the goal of arriving home with 0% charge so I don’t waste any money on DCFC prices. But I only have a relatively level gravel road for the final 2 miles so I know I can get upward of 8-10 miles/kWh on that section without trying.

I suppose the 2 mile hike home should be good exercise if it did shut down and an easy trip to go back and get it unless it regenerate a little on its own if it sits for a while. Getting stuck on a big city freeway during rush hour isn't a fun way to get exercise.

 

[Lightningwaiter]

Just wondering if it's good for the battery to charge to 100% every once and awhile. I've had the truck since August of last year and it was 100% when I picked it up. I did a max charge for one mid range trip and that's about it.

I normally charge to 80%.

I change to 90% every day but only on longer trips which is not that often.

 

[SpaceEVDriver]

I suppose the 2 mile hike home should be good exercise if it did shut down and an easy trip to go back and get it unless it regenerate a little on its own if it sits for a while. Getting stuck on a big city freeway during rush hour isn't a fun way to get exercise.

I can’t comprehend running out of charge in an ocean of chargers.

 

[Ragman]

Just wondering if it's good for the battery to charge to 100% every once and awhile. I've had the truck since August of last year and it was 100% when I picked it up. I did a max charge for one mid range trip and that's about it.

I normally charge to 80%.

100% regularly, sitting at Tesla right now fast charging at 171 kw. At 100k km service (60k miles) had dealership test battery - 98.5%.

Charge it and drive it - my two cents. Ford did a great job with battery buffers.

 

[Firn]

I've also seen the > 10 kWh lost during 99-100% cell balancing into resistive loads. So, don't do it everyday. If your battery cells grow too imbalanced, the truck will throw wrench icon with Service Soon warnings and you might need a module replaced. The longer you go without cell balancing, the more a voltage imbalance can grow. So, perform a top-balance periodically. If we do lose 10 kWh into those resistors during a top-balance, performing this once a week costs <$100/y at my rates. I'd aim for weekly - $1k/10y, cheap battery maintenance much cheaper than ICE maintenance.

It's been posted the truck battery management software will balance if it's been unplugged and OFF for 48h. It's unclear how well this works in practice. As you can see from the top-balance's potential 10 kWh energy usage, the truck won't balance to this same level when OFF... the standard range would lose 10% if it did the same amount of balancing.

Pretty sure its not "lost", its that the battery was mis-reporting the capacity before.

I know when I charge to 100% charging slows dramatically at 99%, which indicates it isn't doing resistive power shedding but in fact tapering power delivery to only deliver energy to the low cells.

"Proven"...in accelerated / synthetic lab tests, yes.

Few of these tests mimics real life usage (because it would simply take a decade vs. 6 months or whatever it is).
For example, does it cause more harm to have your battery sit at a high SoC (80-90%) all the time compared to a deeper/extended charge cycle once a week ?
Nor do they look at a more realistic range of 30-80 vs. 70-80-90, but we take their 0/10-100% tests as proof that ABC is the "law" we shall all abide by.

Besides, if you're going to ABC it's probably better to be in the 40-60% span than it is to always charge from 70-90%.

Every test i have seen on the subject uses various ranges, not 0/10/100. Iirc there was

Since last October when I got mine, I plug in every night and charge to 100%. No messing around. I drive to the VA in Wichita often enough or who knows when I might decide to drive over 200 miles in a day. I'm not interested in getting caught somewhere with a low battery trying limp home. Sometimes I only drive 30 miles or maybe a 100 miles but if I wake up one day and decide to go for a long drive, I want to be ready. Those are the drives that I don't want to have to resort to the Prius or Subaru Forester.

Fwiw, 90% or 100% is only 20 miles or so. Probably a pretty rare window where 100% actually makes a difference over 90%.

 

[msdickerson]

Just wondering if it's good for the battery to charge to 100% every once and awhile. I've had the truck since August of last year and it was 100% when I picked it up. I did a max charge for one mid range trip and that's about it.

I normally charge to 80%.

During the winter I charge at home to 100% daily, but when steady 50 degrees or above come in, then I do 90%. My J1772 (20 amp 240 vac) only charges at 4500 watts / @ 10mph . So it is not doing a fast charge.

 

[LakeWorthLuke]

I charge to 85% every day. I put on my calendar for a quarterly task of charging to 100% and disconnecting the 12v battery for 20+ minutes. Seems like a good thing to do quarterly.

edit: sorry, I don't charge *every* day, but just whenever I charge. I have a short commute so it's usually just 2-3 times a week.

Curious, why disconnecting the battery for 20 mins? What does that do?

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