Update on Mach-E launch progress from engineering friends in Mexico

[Badger_Prof]

Generally speaking you're right, although consensus is that when charged to 100% you should start your trip immediately. And most advise for longer periods without use (holiday without MME, unthinkable) a charge of around 50% and when possible connected to the charger.

Consensus of whom? That statement is inconsistent with what I have read elsewhere on this site (lots of different opinions versus consensus) and inconsistent with what I have read elsewhere. Do you have a citation to support those numbers? Thanks.

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[JamieGeek]

If you plug it into a 120 would it still do this?

Not sure as I never plugged it into 120V.. It was always plugged into my Level-2 (240V).

In any case it would still do it if I left it plugged into the Level-2.

 

[kdryden99]

Not sure as I never plugged it into 120V.. It was always plugged into my Level-2 (240V).

In any case it would still do it if I left it plugged into the Level-2.

interesting. Its supposed to charge the 12v while charging on level 2. Unless it shut of the charging after reaching full and therefore would go to sleep. I wonder if using a trickle charger on the 12v would prevent this? I dont even know if putting a trickle charger on the 12v on these ev's is a good idea.

 

[SnBGC]

interesting. Its supposed to charge the 12v while charging on level 2. Unless it shut of the charging after reaching full and therefore would go to sleep. I wonder if using a trickle charger on the 12v would prevent this? I dont even know if putting a trickle charger on the 12v on these ev's is a good idea.

I dont think so on the FFE. The EVCC (Electric Vehicle Computer Controller ) won't allow the TCM (Transmission Control Module) to power the DC to DC Converter which charges the 12v battery. Not while charging on L1 or L2. Is possible on DCFC though.

 

[Marcel]

Consensus of whom? That statement is inconsistent with what I have read elsewhere on this site (lots of different opinions versus consensus) and inconsistent with what I have read elsewhere. Do you have a citation to support those numbers? Thanks.

Sorry, most are from experts on the dutch tweakers.net forum (in Dutch and very large so not easy to find)

Engineering explained ,Tesla Bjorn from you tube.

https://www.motortrend.com/news/ev-lithium-ion-battery-life-tips-tricks-advice/

6 Ways To Extend EV Battery Life

1. Minimize exposure to high temperatures, in storage and use—Park your EV in the shade whenever possible or plug in so that the battery's thermal management system can function using grid power.
2. Minimize exposure to low temperatures—Here again, the danger is mostly parking unplugged in extreme low temperatures. If you can plug in, the battery's thermal management system can keep the battery comfy. Some EVs automatically run the thermal management system even unplugged, until capacity drops to 15 percent, after which things get ugly.
3. Minimize time spent at 100 percent state of charge—Try to resist the urge to plug in all night every night. If your daily travels consume 30 percent of the battery, using a middle-30-percent (like from 70 to 40 percent) is better for the battery than always using the top 30 percent. Smart chargers will eventually integrate with your calendar to anticipate daily driving needs and tailor charging to suit.
4. Minimize time spent at 0 percent state of charge—Battery management systems typically shut an EV off well before reaching 0 percent. The bigger danger is leaving a vehicle unplugged for so long that it self-discharges to zero and stays there for a prolonged period.
5. Avoid using fast charging—Automakers know that one of the keys to mass EV adoption is the ability to charge as quickly as filling a gas tank, so they're timid about warning against high-voltage DC charging. And indeed it's fine for recharging during infrequent long trips—or for when a surprise appointment depletes your strategic 70-percent overnight charge. Don't make it a habit.
6. Avoid discharging more quickly than is needed—It's tough to resist those Ludicrous Tesla launches, and they're relatively harmless when enjoyed occasionally when demoing your car to a prospective EV convert. Just know that each one hastens the ultimate demise of your vehicle's battery by some amount.

Some tips for operating your EVs:

• Avoid keeping your car sitting with a full or empty charge. Ideally, keep your SOC between 20–80% particularly when leaving it for longer periods, and only charge it fully for long distance trips.
• Minimize fast charging (DCFC). Some high-use duty cycles will need a faster charge, but if your vehicle sits overnight, level 2 should be sufficient for the majority of your charging needs.
• Climate is out of an operator’s control, but do what you can to avoid extreme hot temperatures, such as choosing shade when parked on hot days.
• High-use is not a concern, so fleets shouldn’t hesitate to put them to work. An EV isn’t useful sitting idle in the fleet yard, and putting on more miles per vehicle is overall a better fleet management practice.

,

https://www.sciencedirect.com/science/article/abs/pii/S2352152X19314227?dgcid=author

 

[timbop]

This article is one of many that uses actual data: https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

A key graph from that article says it all:

 

[Shayne]

2. Minimize exposure to low temperatures—Here again, the danger is mostly parking unplugged in extreme low temperatures. If you can plug in, the battery's thermal management system can keep the battery comfy. Some EVs automatically run the thermal management system even unplugged, until capacity drops to 15 percent, after which things get ugly.

Good summary. Pretty easy rules that have circulated for awhile. Two, with a power outage, is the only one that could be a pain. I have a 120v generator but I understand L2 (installed on grid now) maybe best for extreme cold. High tech block heater and I have no heated storage. I think I will be following good battery maintenance practices as best as I can. Looking forward to success stories.

A key graph from that article says it all:

I understood 80-20 not shown on the graph. Guess it would be somewhere between blue and green. The way we are moving around lately orange maybe doable but not really practical.

Lots of data around and no one should be too surprised. Cycles are not that visual to me.

What can 6,000 electric vehicles tell us about EV battery health

Hold back gone in 6 years; I do not think we should worry too much but good to be aware it can be minimized when possible.

 

[timbop]

I understood 80-20 not shown on the graph. Guess it would be somewhere between blue and green. The way we are moving around lately orange maybe doable but not really practical.

To me the most striking difference is for those that use about 50% of their battery and then plug in to recharge. If you follow your normal inclination from an ICE and charge to 100% and "refill" at 50%, you'll see 10% degradation after 1500 cycles. If on the other hand you charge to 75% and recharge at 25%, it will take 3000 cycles to see 10% degradation. Granted 1500 charges is an awful lot (3 times a week for 10 years), but depending on battery size and daily commute conditions it could be as little as 100,000 miles. That's assuming your daily 50 mile commute is mostly highway and accounting for seasonal variations in efficiency.

 

[Shayne]

To me the most striking difference is for those that use about 50% of their battery and then plug in to recharge. If you follow your normal inclination from an ICE and charge to 100% and "refill" at 50%, you'll see 10% degradation after 1500 cycles. If on the other hand you charge to 75% and recharge at 25%, it will take 3000 cycles to see 10% degradation. Granted 1500 charges is an awful lot (3 times a week for 10 years), but if you follow the pattern of going 100%-25% it only takes 1000 cycles to lose 10%.

I guess you always plug it in to keep the battery management system operational but you do not need to charge it till you get down to 25%; knowing your future commutes. Phone batteries have taught us the basics. Wonder if you can set it up in the schedule to start charging @25% and charge to 80 and not just schedule the charging times?

 

[dbsb3233]

This article is one of many that uses actual data: https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

A key graph from that article says it all:

Question to clarify what they mean by "cycles" here. Do they mean just charges of the length stated? For instance, let's look at the 4000 cycles point on the x-axis. The orange line is the best but it's only adding 10% on each cycle (if I understand it right). On the MME ER that's just 8.8 kWh x 4000 = 35,200 kWh. While on the dark blue line, it's adding 75% each cycle. That's 66 kWh x 4000 = 264,000 kWh. That's 7.5x more kWh being run through, so of course it's gonna degrade much more.

There's only 2 pairs of lines on there that run the same % of SOC (kWh) through the battery. There's two that do a 40% addition, and two that do a 50% addition. Those are the ones that are really apples-to-apples comparisons. And they do show that charging around the middle rather than the ends is (slightly) better.

Of course, at around 3 miles/kWh mileage, nearly all of those are good for 100k+ miles in the vehicle (most way more), so still plenty for most people either way.

 

[dbsb3233]

Taking that a bit further comparing the worst line (dark blue) to the best line (orange)... there's a 7.5x difference in the amount of kWh (thus miles) between the two.

Let's normalize that for the same number of miles driven... the far right point on the orange curve looks like it degrades to about 92% (8400 cycles). That equates to 1120 cycles on the dark blue line. That looks like degradation to about 89%. Worse, but not nearly as extreme (for the same # of miles) as it appears at first glance.

 

[Marcel]

Taking that a bit further comparing the worst line (dark blue) to the best line (orange)... there's a 7.5x difference in the amount of kWh (thus miles) between the two.

Let's normalize that for the same number of miles driven... the far right point on the orange curve looks like it degrades to about 92% (8400 cycles). That equates to 1120 cycles on the dark blue line. That looks like degradation to about 89%. Worse, but not nearly as extreme (for the same # of miles) as it appears at first glance.

One cycle is 100% charge, wether that is 4 times a 25% charge or 1 time 100%. So cycle does not mean each time you charge but the total of a 100% charge.

 

[dbsb3233]

One cycle is 100% charge, wether that is 4 times a 25% charge or 1 time 100%. So cycle does not mean each time you charge but the total of a 100% charge.

That's what I was asking in the prior post. So they count a full 88 kWh (in the MME ER case) as a cycle? So the orange line really represents 84,000 charges on the far end (daily for 230 years)???

 

[kdryden99]

To me the most striking difference is for those that use about 50% of their battery and then plug in to recharge. If you follow your normal inclination from an ICE and charge to 100% and "refill" at 50%, you'll see 10% degradation after 1500 cycles. If on the other hand you charge to 75% and recharge at 25%, it will take 3000 cycles to see 10% degradation. Granted 1500 charges is an awful lot (3 times a week for 10 years), but depending on battery size and daily commute conditions it could be as little as 100,000 miles. That's assuming your daily 50 mile commute is mostly highway and accounting for seasonal variations in efficiency.

I didn't want to reply since we're off topic but my main concern here is can you plug in the car to warm up the battery without recharging the battery. I live in Quebec where there are nights that we get close to -40

 

[RonTCat]

This article is one of many that uses actual data: https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

A key graph from that article says it all:

This graph tells me I should not care in the least how I charge my battery. Why?

If I own my car for 10 years, using the worst case line:
- Assume 200 charge cycles a year
- 100-25% will be 270 miles x .75 = 202 miles per charge cycle new, 172 at 10 years, 187 average
- The car will have 187 x 2000 = 374,000 miles on it

At 10 years I have already bought (or am buying) a new EV with a 1000 mile range battery.

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