Is AWD worth if you need range?

[Reign of Ravens]

Also DC charging causing battery degradation much faster.

This may not be true. Electrek recently had an article about how Tesla battery longevity does not seem to be impacted by frequent DC fast-charging. Granted, that's Tesla and not our Mach-E's, but I thought it was interesting, and I was also under the belief that DC fast-charging would be worse for batteries. Maybe that only applied to the Nissan Leaf, which does not have an active cooling system for its batteries.

AWD does not affect handling of the car - it just makes taking off much easier on slippery surfaces. It does nothing to help steering or stopping.

I'm not sure that it doesn't impact stopping for our cars. AWD in an electric vehicle usually means there's an entire additional motor in the vehicle. That matters because EVs utilize regenerative braking (engine braking) and ours blend it with the friction brakes when stopping. Having a second motor means more regenerative braking power. It would make sense that stopping capabilities should be at least a bit better on the AWD models.

We only ever hear about 0-60 times. I wish someone would do a 60-0 study because I've never been able to get a definitive answer on this one.

AWD is only needed in Northern climes, otherwise it is a range defeater.

I need it in Hawaii.
Our highway on-ramps are ridiculously short, and some connections to highways don't have any acceleration zone before you're merging with traffic. Faster acceleration is critical.

I guess that's technically just the acceleration boost from the second motor, and not really needing all wheels to be active, but meh... point stands for our vehicles, and what taking AWD gets you.

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[RedStallion]

This may not be true. Electrek recently had an article about how Tesla battery longevity does not seem to be impacted by frequent DC fast-charging.

That amounts to a hearsay. The scientific research clearly shows a significant impact of high speed charging on battery longevity. I already posted this link before, here it is again:
Fast-charging damages electric car batteries

 

[Reign of Ravens]

That amounts to a hearsay. The scientific research clearly shows a significant impact of high speed charging on battery longevity. I already posted this link before, here it is again:
Fast-charging damages electric car batteries

Was it because I posted an article from Electrek? Here's the original article. They don't disagree that high heat conditions can damage batteries, which is the crux of the article you posted. What they found is that "occasional" DC fast-charging is fine. They don't clearly state what frequency that might be, but they note that Tesla Model 3 owners who reported DC fast-charging 90% of the time had no significant difference in degradation compared with people who used DC chargers 10% of the time. I'd assume that means you might take a hit to battery health when DC fast-charging multiple times a day while road-tripping, but if you tend to visit a DC fast charger 1-3 times per week as you would a gas station for an ICE vehicle, you're fine. (Assuming you drive a Model 3 - again, that's what the data shows, and it requires a fair assumption to say it applies to other EVs as well.)

The article you posted may not be outright lying, but there is a sensationalist aspect to it. Their motive to do so is commercial bias: they have patented a fast-charging algorithm to try and prevent degradation when fast-charging, and probably hope that all EV manufacturers will implement it and pay them royalties. I'd also have to criticize their methodology, because it seems that they put the battery through various cycles in isolation. We've come a long way from the old passively-cooled battery packs of the Nissan Leaf, and our EVs do have active cooling for the battery packs.

Nobody disagrees that heat can damage batteries. The question is how significant an issue it is when you look at the entire system combined, and what we're using it for.

 

[RedStallion]

Was it because I posted an article from Electrek? Here's the original article.

No, I looked at the original article. There is nothing scientific about it or about the company that promotes it, no science journal would ever publish it.
The article I referred to has the reference to the original study, with all the numbers everybody can check and reproduce. There are many peer reviewed research papers on that matter, even a cursory search on internet would show several. There are different mechanisms that cause degradation, both thermal and electro-chemical, you can find charts showing a steep degradation at high c-rates. You can mitigate thermal effects by temperature management (to a degree, there can be over 20C gradient in temperature between the battery core and casing), but other effects are caused directly by the current.

 

[SolarAB]

I think it depends on the manufacturer.

I know for the heat pump in my house, you can hit “emergency heat” when it’s super cold outside and the heat strip turns on to help the pump.

Either way, heat pumps are really only good for places with mild winters. That why we have them in Florida but they aren’t popular up north.

We just installed a heat pump here in Alberta. I'll let you know how it works out after our first winter. The AC part has been good.

 

[Space_Pony]

We just installed a heat pump here in Alberta. I'll let you know how it works out after our first winter. The AC part has been good.

I hope it was a ground source heat pump with pipes buried 10 ft. deep.

 

[Mach1E]

I hope it was a ground source heat pump with pipes buried 10 ft. deep.

Lol yeah, I wouldn’t expect his heat pump to look or work anything like mine.

Mine looks like this and is just outside above ground-

 

[superdave80]

What they found is that "occasional" DC fast-charging is fine.

There was a whole thread discussion on that study from Recurrent. I'll just point out that Recurrent uses the range indicator (aka, Guess-O-Meter) to gauge battery health. They don't actually measure battery health directly.

Their motive to do so is commercial bias: they have patented a fast-charging algorithm to try and prevent degradation when fast-charging, and probably hope that all EV manufacturers will implement it and pay them royalties.

And Recurrent wants you to use their battery health reports to sell EVs through them. Everybody is out to make a buck.

 

[Mach-Lee]

That amounts to a hearsay. The scientific research clearly shows a significant impact of high speed charging on battery longevity. I already posted this link before, here it is again:
Fast-charging damages electric car batteries

I think that is a flawed study because they chose a deliberately hard "industry standard" charging cycle that was anything but:

1. The battery was charged at a rate of 2C until the battery capacity reached 1920 mAh (60%) or if the battery voltage reached 4.2 V.
2. The battery is then rested for 5 min.
3. After resting the battery is charged again at a lower rate of 0.6 C until the battery
   voltage reaches 4.2 V.
4. Once the battery voltage reaches 4.2 V the battery is charged under CV for 30
   min.

They also had no cooling and allowed the cell temps to reach 60ºC without interrupting the charging and charged to 100% each time. No EV would allow the voltage or temps to get that high during DC charging, they would derate to protect the pack. So yeah, they cooked the cells really fast in their study. Not surprised. Real word charging is more conservative so that won't happen.

 

[Mach1E]

I think that is a flawed study because they chose a deliberately hard "industry standard" charging cycle that was anything but:

1. The battery was charged at a rate of 2C until the battery capacity reached 1920 mAh (60%) or if the battery voltage reached 4.2 V.
2. The battery is then rested for 5 min.
3. After resting the battery is charged again at a lower rate of 0.6 C until the battery
   voltage reaches 4.2 V.
4. Once the battery voltage reaches 4.2 V the battery is charged under CV for 30
   min.

They also had no cooling and allowed the cell temps to reach 60ºC without interrupting the charging and charged to 100% each time. No EV would allow the voltage or temps to get that high during DC charging, they would derate to protect the pack. So yeah, they cooked the cells really fast in their study. Not surprised. Real word charging is more conservative so that won't happen.

Flawed for sure, but one thing I learned (and makes me feel kinda dumb) is that our battery packs are basically thousands of AA batteries!

In my mind they were larger cells and looked nothing like something I put in my TV remote.

 

[Mach-Lee]

Flawed for sure, but one thing I learned (and makes me feel kinda dumb) is that our battery packs are basically thousands of AA batteries!

In my mind they were larger cells and looked nothing like something I put in my TV remote.

Mach-E batteries are actually pouch cells, not individual cylindrical cells like Tesla:

 

[bbulkow]

I need it in Hawaii.
Our highway on-ramps are ridiculously short, and some connections to highways don't have any acceleration zone before you're merging with traffic. Faster acceleration is critical.

I find it hard to believe. Given that a RWD MachE is faster than 90% of the ICE vehicles, you're saying that most normal ICE vehicles like honda civics can't be driven in hawaii? Really? I rented a car in hawaii and it was nothing special and I had to stomp it now and then but I thought nothing of it.

The RWD has PLENTY of get up and go for non-competition driving. I was on 101 today and we have a lot of those big commuter busses, I had to do some hard acceleration and squeeze into some spots. No problem; point and go.

I am sure I'd have more fun had I bought an AWD. If I had numbers I believed showing AWD range is within 2% (as some claimed), I would have gone for it. The consensus was closer to 5% to 10% and I wasn't willing to pay that for a little extra fun factor.

 

[RedStallion]

I think that is a flawed study because they chose a deliberately hard "industry standard" charging cycle that was anything but:

1. The battery was charged at a rate of 2C until the battery capacity reached 1920 mAh (60%) or if the battery voltage reached 4.2 V.
2. The battery is then rested for 5 min.
3. After resting the battery is charged again at a lower rate of 0.6 C until the battery
   voltage reaches 4.2 V.
4. Once the battery voltage reaches 4.2 V the battery is charged under CV for 30
   min.

They also had no cooling and allowed the cell temps to reach 60ºC without interrupting the charging and charged to 100% each time. No EV would allow the voltage or temps to get that high during DC charging, they would derate to protect the pack. So yeah, they cooked the cells really fast in their study. Not surprised. Real word charging is more conservative so that won't happen.

Of course, they had to accelerate the aging process, how else could they complete the study and compare the effectiveness of their method. It's a common practice. I have an SSD storage device with 100 year reliability rating. How do you think they did the testing?

 

[superdave80]

Flawed for sure, but one thing I learned (and makes me feel kinda dumb) is that our battery packs are basically thousands of AA batteries!

In my mind they were larger cells and looked nothing like something I put in my TV remote.

Mercedes actually made a AA-class vehicle... well, according to Saturday Night Live.

https://iplayerhd.com/player/video/dae6a69a-adb1-4692-aaba-cff7e6bcd493

 

[superdave80]

Of course, they had to accelerate the aging process, how else could they complete the study and compare the effectiveness of their method.

By using actual industry standard charging, but doing it more frequently to get X number of cycles in a shorter time. The fact that the batteries are splitting open after just 60 cycles should be a sign that this test has issues.

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