Many recent posts about installing the fastest charger and why this might not be the best approach?

[machefan]

I see many recent posts about installing the fastest charger possible. I would like to note that if you can charge at slower rates such as L1 (120V ~1.4kW 13 AMPS) or even L2 (220V ~3.6kW 16 AMPS) it's less stress on the battery long term. If you are always charging at L2 (~7.2 KW) 32 AMPS and then even the faster 40 AMPS or 48 AMPS it increases the battery degradation rates. Battery babying is still a thing if one wants their range to stay at factory numbers. This typically starts when the car new and is best approached by how you are charing your MACH. Ford's LG battery will not be any different than previous generations of EV's. The more you stress the battery the more degradation you will experience. There is an entire internet following on this very topic, give it a search. DC fast charing at 100+ kW is even more taxing and should be avoided if not really needed. The MACH-E has a fully battery management system that cools, slows DC charging and preserves the top and bottom end of the battery, this will help but it can only do so much. Even in the manual it says to only charge to 90% on a daily basis and to not always DC fast charge.

So the moral of my post is to just call this out as one should consider the slower chargers if one really isn't in a hurry. Example would be such as you get home at 6 PM and not needing to go out again till the 6 AM in the morning. For that scenario I personally use my L1 or L2 depending on how much charge is left on my current EV (LEAF). Also I suggest not charging daily if you don't need to, so if you daily ride is ~20% of battery use and you start at ~90%, maybe wait till your at ~30% before charing. Also parking in the hot summer sun at 90% or even 100% for a long periods of time should be avoided, but that's another topic.

Another thought on why plug-in chargers could be preferred over direct wall chargers. Also the 120V which is just a pig-tail on the included Ford charger might be enough for many on day 1.

Just food for thought / discussion, not trying to insight a riot

 

[JamieGeek]

Riot insighted:

I would argue that the fastest Level-2 still doesn't damage the battery nearly as much as DCFC and you can safely charge at the highest Level-2 rate as often as you want.

Considering that the battery is a set of cells (288 for SR, 376 for LR) each cell is going to get a its piece of the charging current. Worst case SR at 48 amps each cell gets 160ma, or 32 amps each cell gets 110ma--really not much of a difference there.

The recomendation for charging to 90% isn't about charging cycles or rate its about "time at full": another metric for battery degredation. The longer the battery sits at 100% the worse it is. Thus by only charging to 90% you're limiting the amount of time the battery is full. (In addition: If you commute daily--yeah not right now--then you can setup a go time and charge to 100% since you'll be driving it right after the 100% charge. I used to do this with my Focus Electric and experienced NO battery degredation in the 3 years I had it.)

 

[dbsb3233]

I've wondered whether lower home charging power might be better too. But even 40A or 48A is pretty low in the grand scheme of things (WAY lower than any DCFC), so I'm not sure that makes much difference.

I put in a Grizzl-E that defaults to 40A. But we drive relatively little, and could easily get by with 32A, 24A, or even 16A on a regular basis. Heck, even 120V 8A would suffice most of the time. It's a topic I'll be curious to follow and see what experiences are. Problem is it's all still relatively new and the impacts won't be known for years.

 

[dbsb3233]

The longer the battery sits at 100% the worse it is. Thus by only charging to 90% you're limiting the amount of time the battery is full.

The passage in the manual that raised an eyebrow for me was the recommendation for only 50% if sitting unused for 30 days. That suggests to me that it really is better around 50% than 90%, even if 90% is "OK" most of the time.

While ours will never sit unused for 30 days, we do regularly go a few days in a row without leaving the house. 3-4 days unused will be semi-common. While that's a long way from 30 days, I'm leaning toward an 80% stopping point now rather than 90% based on extrapolation of the manual recommendation.

 

[txaggies07]

The passage in the manual that raised an eyebrow for me was the recommendation for only 50% if sitting unused for 30 days. That suggests to me that it really is better around 50% than 90%, even if 90% is "OK" most of the time.

While ours will never sit unused for 30 days, we do regularly go a few days in a row without leaving the house. 3-4 days unused will be semi-common. While that's a long way from 30 days, I'm leaning toward an 80% stopping point now rather than 90% based on extrapolation of the manual recommendation.

40-50% is the optimal storage % for nearly all lithium ion batteries. Cell phones are the same way.

 

[JamieGeek]

The passage in the manual that raised an eyebrow for me was the recommendation for only 50% if sitting unused for 30 days. That suggests to me that it really is better around 50% than 90%, even if 90% is "OK" most of the time.

While ours will never sit unused for 30 days, we do regularly go a few days in a row without leaving the house. 3-4 days unused will be semi-common. While that's a long way from 30 days, I'm leaning toward an 80% stopping point now rather than 90% based on extrapolation of the manual recommendation.

Yeah the Focus Electric's owner's manual had the same thing about long-term storage.

For charging its pretty much about heat dissapation. If I re-do my above calculations in Watts:

For the SR battery with 288 cells:

• Level-1 charging at roughly 3kW is ~10W/cell
• Level-2 charging at roughly 7.6kW (32 amps) is ~26W/cell
• Level-2 charging at roughly 11.5kW (48 amps) is ~40W/cell
• DCFC at 115kW (fastest for SR) is ~400W/cell

For the ER battery with 376 cells:

• Level-1 charging at roughly 3kW is 8W/cell
• Level-2 charging at 7.6kW (32 amps) is 20W/cell
• Level-2 charging at 11.5kW (48 amps) is 30W/cell
• DCFC at 150kW (fastest for ER) is ~400W/cell

(Look at that DCFC for both SR and ER is 400W/cell--you'd almost think Ford designed it that way!)

So we're talking Level-2 is an order of magnitude faster than Level-1 and DCFC is an order of magnitude faster than DCFC.

(Yeah I know it likely isn't as simple as the math above would imply simply because the cells are grouped in a serial+parallel arrangement instead of all being in parallel. Its still good enough for comparisons sake.)

The question is: Does the 10+W difference between Level-1 and Level-2 make that much of a difference? I doubt it generates that much more heat and since the cooling system in the Mach-E is designed for getting rid of that big 400W load I'm sure that extra 10W is nothing.

Note that the OP's reference car is a Leaf which has no active battery cooling and thus this may make more of a difference than it would for the Mach-E (which can maintain optimal temps for the batteries during a long Level-1 or Level-2 charge...hot or cold).

Thus my takeaway is: doesn't matter, plug it in and charge.

Of course I've argued on here before that people don't need to spend the extra $$ for the Ford Connected charger because they may not need that speed. That argument wasn't based on battery preservation but simple economics: the return on that investment isn't worth it in my mind. We're also talking about a $50+k vehicle so if you can afford the car you can afford the chargers (Same argument on RV forums: You'll see people with $250+k motorhomes looking for free campsites??)

 

[Redundant]

In the distant past I seem to recall that when you got new rechargeable devices you were supposed to run them close to 0 and recharge full or batteries could take on a memory with lower capacity. Is that not an issue anymore if it was ever an issue at all?

 

[ajmartineau]

For a battery, power in and power out are the same amount of stress.
Driving at 12kW is equal to less than 60 mph.
L2 charging is doing less damage than using that charge.

Do the math a how much stress you put on the battery doing 0-60 in less than 5 seconds.

 

[highland58]

In the distant past I seem to recall that when you got new rechargeable devices you were supposed to run them close to 0 and recharge full or batteries could take on a memory with lower capacity. Is that not an issue anymore if it was ever an issue at all?

I think that was Ni-Cad batteries that had battery memory, I don't remember hearing that Lithium batteries have that issue.

 

[shutterbug]

I think that was Ni-Cad batteries that had battery memory, I don't remember hearing that Lithium batteries have that issue.

In the early days Lithium batteries, manufacturers, motivated by laziness, inertia, and general corporate dumbassery, were still recommending that their devices be periodically run down to zero, to preserve battery health. As recently as 10 years ago, Lenovo was still recommending that and actually explained how to do it without crashing Windows.

 

[RonTCat]

For a battery, power in and power out are the same amount of stress.
Driving at 12kW is equal to less than 60 mph.
L2 charging is doing less damage than using that charge.

Do the math a how much stress you put on the battery doing 0-60 in less than 5 seconds.

Prolly >260kW, so about double the DC charge rate. I'm with you, I don't get the level of concern about charge rates.

 

[dbsb3233]

Hey Enthusiasts -

Assume:

1. L1 charging provides 3 miles range in an hour.
2. Your car is plugged in 12 hours per day.
3. Then this charging will provide your Mach e 252 miles of range per week, or around 13K of range per year.

For me, I also may take advantage of a local "free" 7.2 KW public charger, too. (You always need something at Walmart, right?). So, L1 charging may be a reasonable option. I may do this while waiting for home charging station incentives to get even better!

That was originally gonna be my plan too, since we only drive maybe 5k-8k miles/year in retirement. But then the 30% federal tax credit for 2020 changed my mind. Figured I might as well get it now since it's all effectively 30% off before the end of the year.

 

[ClaudeMach-E]

I've wondered whether lower home charging power might be better too. But even 40A or 48A is pretty low in the grand scheme of things (WAY lower than any DCFC), so I'm not sure that makes much difference.

I put in a Grizzl-E that defaults to 40A. But we drive relatively little, and could easily get by with 32A, 24A, or even 16A on a regular basis. Heck, even 120V 8A would suffice most of the time. It's a topic I'll be curious to follow and see what experiences are. Problem is it's all still relatively new and the impacts won't be known for years.

That is the main reason why I would like to have a current set up for AC charging on the Ford Pass app and/or directly in the Sync 4A just like you can do in a Tesla. That way when you don't need much you can set it for 8 Amp and if you need a full charge then set it to 32-40 or 48 Amps. But it does not seem to be there for now, so an email to the EVteam is the thing do do. Anyone has an email address I can use?

 

[shutterbug]

Hey Enthusiasts -

Assume:

1. L1 charging provides 3 miles range in an hour.
2. Your car is plugged in 12 hours per day.
3. Then this charging will provide your Mach e 252 miles of range per week, or around 13K of range per year.

For me, I also may take advantage of a local "free" 7.2 KW public charger, too. (You always need something at Walmart, right?). So, L1 charging may be a reasonable option. I may do this while waiting for home charging station incentives to get even better!

This may indeed work for you, but not for everyone. My TOU rate kicks in @ 8:00 PM, but in the summer I would prefer to start charging @ midnight. Once we start going back to the office, I'll be starting @ 6:00 AM. So suddenly that 12 hour a day charging becomes 5 hour a day. Then one day the 10mi commute turns into several trips around town totaling 150mi. so you spend $50K for MME, but end up with a functional equivalent of a $30K Mini

 

[SnBGC]

For a battery, power in and power out are the same amount of stress.
Driving at 12kW is equal to less than 60 mph.
L2 charging is doing less damage than using that charge.

Do the math a how much stress you put on the battery doing 0-60 in less than 5 seconds.

I think we all agree that slower charge rates are better than higher rates (all else being equal).

I agree charge and discharge have the same thermal and degradation effect on the EV battery. L1 and L2 charging is wayyyyy down on the list of things we should worry about when it comes to battery preservation.

If you really want maximum battery health then avoid DCFC and if you must, then the lowest charge rate is best. Nobody wants to hear that though. Everybody wants the fastest DCFC rate possible and battery health be damned.

High levels of regen also damages the battery. But again.....everyone wants 1 Pedal driving with max regen levels without understanding how it affects the battery.

0-60 sprint's are not kind either. I can demonstrate this on my FFE. Not that it is super quick but the principal is the same. Here in Phoenix during the summer it can be 115 degrees or more. I drive around with A/C on of course and it works fine. However, I have to be careful not to accelerate too aggressively because the battery temp will increase and then the car will redirect all the energy to the chiller for the battery and none to the passenger cabin. A/C will blow warm for 30-60 seconds or so until the battery temp stabilizes.

Point being that how we drive the vehicle is just as important to battery health as how we charge the vehicle and even how we park it in the heat.

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