What IS the recommended Level 2 maximum battery charge limit?

[MaineSailor]

OK - I've done some searching on this subject, and find a lot of threads on how to set the upper charge limit on the MME - just not what that upper limit should be. Read the users manual, and see the recommended 80% charge at DC fast chargers - but nothing on upper limit for at-home Level 2 charging.
My set-up: Standard range MME / Grizzl-E 240V 40 Amp "dumb" charger. I do almost all charging at home.

I've read (somewhere) that Ford has built in a buffer at the top of the charge range, so when the car says it's at 100%, it's really more like 90% of actual battery capacity. If anybody can point me to some solid info on this, I would appreciate it! Happy (electric) Motoring!

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[Nklem]

90% Page 149 of the Owners Manual. 100% only if leaving immediately upon charge completion.

 

[Swirls78]

Any help would be great. I tried to program my phone/key to stop charging at 80% while at home. However, it did not stop charging at the 80%. Any suggestions as to why that is happening?

 

[Mach-Lee]

Any help would be great. I tried to program my phone/key to stop charging at 80% while at home. However, it did not stop charging at the 80%. Any suggestions as to why that is happening?

Change the setting in the car instead.

 

[Swirls78]

Change the setting in the car instead.

Okay. I will try that. Thanks

 

[engnrng]

90% Page 149 of the Owners Manual. 100% only if leaving immediately upon charge completion.

“Improves longevity” but undefined what that means, probably because Ford won’t know what that means for another decade or two. Based on info from the battery supplier for our 36,000 lb capacity BEV forklift that my company builds (same battery chemistry, but not the same BMS as Ford), 100% charging daily overnight 5 days per week yields more than 10 years of life. Since I charge my MME about twice per week, I choose to charge L2 at home to 95% (I live on a hill, so gain about 2% on the way down to the city), so about 100 charges per year. Even if that practice shortens longevity by some amount, I expect 20 to 25 years to be above 80% capacity still. DCFC is another story, however. I expect to use DCFC half a dozen times per year, so don’t expect much degradation effect from that. YMMV….

 

[Mach-Lee]

“Improves longevity” but undefined what that means, probably because Ford won’t know what that means for another decade or two. Based on info from the battery supplier for our 36,000 lb capacity BEV forklift that my company builds (same battery chemistry, but not the same BMS as Ford), 100% charging daily overnight 5 days per week yields more than 10 years of life.

Lithium cells don't like high voltages (above about 4.2V/cell) because it causes lithium plating on the anode, which reduces capacity and increases internal resistance. Keeping the voltage below 4.0V/cell prevents that from happening, so that's the basis of the recommendation to only charge to 90% unless you need it. Each manufacturer chooses what voltage to call 100%, so just because it's okay to charge one battery to 100% doesn't mean it's the same voltage or okay on another battery even if they are both lithium. Most forklift batteries are lead acid since the extra weight helps, lithium forklift batteries are still somewhat uncommon.

 

[engnrng]

Lithium cells don't like high voltages (above about 4.2V/cell) because it causes lithium plating on the anode, which reduces capacity and increases internal resistance. Keeping the voltage below 4.0V/cell prevents that from happening, so that's the basis of the recommendation to only charge to 90% unless you need it. Each manufacturer chooses what voltage to call 100%, so just because it's okay to charge one battery to 100% doesn't mean it's the same voltage or okay on another battery even if they are both lithium. Most forklift batteries are lead acid since the extra weight helps, lithium forklift batteries are still somewhat uncommon.

Ok, now you are throwing red herrings around. I should have mentioned explicitly that when I said "same chemistry" I actually meant "same chemistry" which means our batteries are also lithium ion, with the same chemistry as Mache. You are correct, our company is the first forklift of this capacity that uses the same plug and chargers available to automotive EV. And the only battery rating that makes sense is usable capacity. MACHE is 88 kWh, ours is 100 kWh. The Battery Magement System takes care of max cell voltage and, not the battery itself. If you compare cell voltage vs 100 % charge usable, our voltage is the same as the MME. My original post stands. Over 2500 to 3000 charge cycles we expect our battery capacity to remain above 80%. Like Ford, our warranty is very conservative: 5 years or 7000 hours of operation and remain above 70%, a very conservative 900 charge cycles. Fully expect the customer to operate 3x that.

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