(answered)Concern on charging to 100% every charge.

Mirak

Well-Known Member
Joined
Oct 8, 2020
Messages
562
Reaction score
787
Location
Kansas
Vehicles
"Sonic" 2021 MME Grabber Blue First Edition
Country flag
Agreed that charging a lithium battery to 100% regularly is bad for its health as it speeds up the process of dendrite formation. The manual recommends charging to 90% for longevity. But the key point is that there is already a big buffer built in software by Ford, so even 100% is not 100%. The max usable portion of an extended range battery is 88 kWh, but the actual pack capacity is 98.7 kWh, so when you charge it to 100% it's actually only charged to 89% and when you charge it to 90% you're actually charging it to 80%.
I'm not disputing your math, but are we confident that is what Ford is using the actual pack capacity when it recommends only charging to 90%? That seems unlikely to me. For the owner's purposes, the max capacity is 88kWh, so it would seem that Ford is recommending to only charge to 90% of that. Otherwise why would Ford even include the recommendation since you can't charge past 88kWh anyway?





Advertisement

 

CHeil402

Well-Known Member
First Name
Chris
Joined
Sep 21, 2020
Messages
453
Reaction score
776
Location
King of Prussia, PA
Vehicles
2017 Audi A4, 2021 MME
Occupation
Electrical Engineer
Country flag
I'm not disputing your math, but are we confident that is what Ford is using the actual pack capacity when it recommends only charging to 90%? That seems unlikely to me. For the owner's purposes, the max capacity is 88kWh, so it would seem that Ford is recommending to only charge to 90% of that. Otherwise why would Ford even include the recommendation since you can't charge past 88kWh anyway?
I agree. That's my point is that Ford recommends charging to 90% range-o-meter state of charge (which is really 80% battery SOC) to maximize life. But even in the event you regularly charge to 100% you're not actually charing to 100%, so it's not as damaging to the battery and is ok to do regularly as an end user hence the 8 year warranty which is not voided if you regularly charge to 100%.
 

Woeo

Well-Known Member
First Name
Woeo
Joined
Feb 2, 2020
Messages
562
Reaction score
559
Location
Maryland
Vehicles
Fusion Energi
Country flag
Honestly I didn't even look if my Mach-E *has* a glovebox. Can't think of what I'd need or use it for. Just a fancy Cabin Air Filter service door, IMO.
Where do you keep your papers? I have a suggestion if your glove box isn’t your first thought.
 

SteelMach

Well-Known Member
Joined
Feb 12, 2021
Messages
634
Reaction score
622
Location
Michigan
Vehicles
2021 Mustang Mach-E
Country flag
Where do you keep your papers? I have a suggestion if your glove box isn’t your first thought.
Proof of insurance is an app on phone, registration in the wallet with the license.
 

machefan

Well-Known Member
Joined
Jan 14, 2020
Messages
983
Reaction score
1,410
Location
NJ
Vehicles
RR FE 21', Leaf 18' and Wranger 17'
Occupation
IT
Country flag
I agree. That's my point is that Ford recommends charging to 90% range-o-meter state of charge (which is really 80% battery SOC) to maximize life. But even in the event you regularly charge to 100% you're not actually charing to 100%, so it's not as damaging to the battery and is ok to do regularly as an end user hence the 8 year warranty which is not voided if you regularly charge to 100%.
I personally suggest folks follow the manual and this keeps getting asked over and over which is fine. Charge to 90% and you are 80% which takes into account the built in buffer and Fords current recommendation. Battery degradation is a real thing, one can slow it down or speed it up. 100% charge is 90% this is true, because we can only use 88 (kW) of it. The bad part is that 90% leaves some cells full at a high SOC which is not good. If Ford unlike others have found a way to balance this out then 100% would be fine, however I am guessing 90% charge is there for this reason or they wouldn't have put it in the manual.

If I am wrong, I am wrong, charge to 100% and see what happens in a few years, might be very little as others have said might be more. The chance of a battery replacement is rare because 70% of total capacity is not likely more like 95% - 90%. Looking at other EV's with battery management this is about what they experience.

I don't agree going lower than 90% will yield any measurable difference over time.

There are a ton of articles on this but most of it circles around each MFG, no two are alike etc.
 

Advertisement





 


Advertisement
Top