[Chipster]

I've read on this forum and on other sites that "rapid charging" is, or at least can be harmful. If this is so why is it that Tesla's and Electrify America charging systems are (when working correctly) designed to do just that? What exactly is it that fast charging does to the battery array of these cars that is detrimental to their long life? Heat build up? If it is a known issue why then would VW want to offer three years of rapid free charging @ Electrify America locations? What am I missing here?

 

[emtonsti]

Repeated DC fast charge (DCFC) and Battery Life?

We know from the ID.3 manual for this VW MEB platform, that VW suggests regularly limiting charging sessions to 80% to extend battery life. What considerations should be made for fast charging? Is the free (unlimited) EA fast charging a blessing or a curse, especially for those near a EA...

www.vwidtalk.com

 

[Chipster]

Repeated DC fast charge (DCFC) and Battery Life?

We know from the ID.3 manual for this VW MEB platform, that VW suggests regularly limiting charging sessions to 80% to extend battery life. What considerations should be made for fast charging? Is the free (unlimited) EA fast charging a blessing or a curse, especially for those near a EA...

www.vwidtalk.com

I had read this, but it did not address most of my questions.

 

[ixlr08]

I've read on this forum and on other sites that "rapid charging" is, or at least can be harmful. If this is so why is it that Tesla's and Electrify America charging systems are (when working correctly) designed to do just that? What exactly is it that fast charging does to the battery array of these cars that is detrimental to their long life? Heat build up? If it is a known issue why then would VW want to offer three years of rapid free charging @ Electrify America locations? What am I missing here?

Small amounts of fast charging, like occasionally when you are on a long distance trip, will cause a tiny amount of damage to the batteries. The lithium will form dendrites that will eventually short out the battery. This is a natural occurrence and the less often you fast charge, the longer your battery will last. If 10% of your charging is 'rapid', 125kW, chances are you won't notice any difference in battery life. If 50% of your charging is 'rapid', then your battery life will be shorter than those that didn't. With an 8 year battery warranty, will it matter? Do you intend on keeping the car longer than 8 years? With some digging, there are several U-tube videos on this issue.

 

[emtonsti]

I had read this, but it did not address most of my questions.

Nobody really knows for sure how much fast charging, if any amount will significantly degrade the ID.4 battery. We may know when there is enough data from thousands of ID.4 which will have different approaches to charging - if VW shares any of that data. It is not just hot, there are issues fast charging in the cold too. Presumably, the on-board charger is programmed to mitigate some of the well known problems. Both the station and the car change the power during DC fast charge (DCFC).

Most people will charge over night at 240V in their own garage, and maybe fast charge two or three times a year. Probably a few living near an EA charge station will almost exclusively charge for free, particularly those who might intend to only keep the ID.4 for a few years.

Best case, virtually no degradation in useable battery capacity in some number of years. Worst case, we start to see warranty battery replacements for degradation below 70% during the warranty period.

The VW MEB platform is so new, unless some VW engineers have some data with preliminary indications, there is no VW MEB platform information yet about how DCFC might affect battery life/capacity (other than the cautions in the manual). We all have the same question.

 

[Huey52]

Since 3 years of fast charging offered (USA) within an 8-year battery warranty one would like to think VW has done the worst case reliability-availability analysis, along with maintainability. I wouldn't really expect anyone to do only fast charging but it is of course a possibility for those close by a station and wanting to fully embrace those savings. Yet another 'we shall see.'
I really am impressed with the 8-year warranty as the inaugural Chevy Volt (hybrid) was limited to 3-year lease only.

 

[ChristophW]

The basic degradation mechanisms of Li-containing batteries are well understood, as @ixlr08 pointed out. And we know that fast cycling, deep cycling, and extreme temperatures all make it worse.

What is much harder to get a grip on is how lots of battery cells working in tandem under a complex battery management system and some level of temperature control behave over time. We can simulate parts in the lab, but only real life will tell the full story. Methinks there is a lot of room for improvement over time as we obtain real-life data and VW can then adjust battery management (both electronic and thermal) and charger parameters via over the air updates. From an engineering perspective, this will be fun to be part of.

In the meantime, I am with @Huey52. VW likely know quite well what they are doing with 3 year fast charging and the battery warranty.

 

[Vwvkk]

The basic degradation mechanisms of Li-containing batteries are well understood, as @ixlr08 pointed out. And we know that fast cycling, deep cycling, and extreme temperatures all make it worse.

What is much harder to get a grip on is how lots of battery cells working in tandem under a complex battery management system and some level of temperature control behave over time. We can simulate parts in the lab, but only real life will tell the full story. Methinks there is a lot of room for improvement over time as we obtain real-life data and VW can then adjust battery management (both electronic and thermal) and charger parameters via over the air updates. From an engineering perspective, this will be fun to be part of.

In the meantime, I am with @Huey52. VW likely know quite well what they are doing with 3 year fast charging and the battery warranty.

In particular Tesla is known to have addressed concerns with fast charging with their active management system as alluded above. There are many YouTube videos talking about Tesla batteries not degrading with supercharging. VW has an externally sourced battery management system so it’s possible this evolves with the firmware Also

FWIW I had asked Dustin many weeks and below is the response which could be considered vw’s official response:

“Thanks for the email. To put it simply you shouldn’t worry about fast charging - the battery is designed to be fast charged, and has cooling and active management. ”

 

[emtonsti]

In particular Tesla is known to have addressed concerns with fast charging with their active management system as alluded above. There are many YouTube videos talking about Tesla batteries not degrading with supercharging. VW has an externally sourced battery management system so it’s possible this evolves with the firmware Also

FWIW I had asked Dustin many weeks and below is the response which could be considered vw’s official response:

“Thanks for the email. To put it simply you shouldn’t worry about fast charging - the battery is designed to be fast charged, and has cooling and active management. ”

I think that's probably the case, less worry about DCFC, but somewhat at odds with the manual - "Avoid regular fast charging with direct current (DC) due to the high charging currents." (well all we have so far is the European manual, but probably the same on this point.)

 

[ChristophW]

I think that's probably the case, less worry about DCFC, but somewhat at odds with the manual - "Avoid regular fast charging with direct current (DC) due to the high charging currents." (well all we have so far is the European manual, but probably the same on this point.)
View attachment 1337

That's mostly how I treat all my rechargeable batteries, and it pays off in the long run regardless of chemistry. Well, they do get charged to 100%, but gently.

 

[Huey52]

I'm pretty religious these days of not recharging Li-ion devices until they get down to 40%. My present devices also get recharged to 100% but for the ID.4 with my ChargePoint I'll be App-limiting it to 80%. Nice feature!

But then I'm the type of guy who also religiously applies StaBil 360 marine to my ICE vehicles/equipment to help stave off the deleterious effects of forced-ethanol.

Yes, I've got some strange "religions." 🤪

 

[Vwvkk]

Some people ( such as apartment dwellers ) don’t have the option of home charging we home dwellers do especially in the US. The Id.3 may be even more a target market for this, but I‘m sure VW doesn’t want to have to honor its 8 warranty in a widespread way.

Having said that, I will be taking care of my battery since I expect this to be a long term purchase.

 

[air]

When I asked VW USA Rep about needing to DCFC the ID.4 once a week at EA stations, they said that it'll be fine if I don't have access to Level 2 charging at home. I'm thinking I'll be okay DCFC a couple times a month if we decide to get an ID.4 this year.

 

[emtonsti]

When I asked VW USA Rep about needing to DCFC the ID.4 once a week at EA stations, they said that it'll be fine if I don't have access to Level 2 charging at home. I'm thinking I'll be okay DCFC a couple times a month if we decide to get an ID.4 this year.

That's probably okay. Another possible option might be to see if there are any 240V, L2 charge stations near you. In NY, and probably other states, there are still some L2 stations that are both free parking and free charging (often at libraries, colleges, local parks, and municipal buildings). You can look for stations on any of the many Apps, "Plugshare" is a good one (some indicate outdated information for their local area, while it is up to date for other areas). I guess our ID.4 will have a built in database of charge stations too.

Some free charge stations are just one or two plugs and more in demand. However, there is a municipal building not far from me with a row of something like 10 free L2 chargepoint stations. I have never seen more than two cars there at a time.

Just an option to consider. Even with the best L2, it will be a longer charge time; maybe even drop the car off and go pick it up four+ hours later.

 

[ErickF]

In the Seattle area, because of COVID, there are numerous free, publicly-accessible L2 chargers in business parks that are always open (I have a T-Mobile office a few blocks with 6 plugs). My plan is to make a game of it before getting a wallbox installed in my garage before next winter.

 

[egsell]

I'm gonna be all about gaming with this car; hunting for cheap free power as well as trying to hyper mile when the opportunity strikes. It'll drive my family insane

 

[ErickF]

I'm almost as much my dad as he was. Lots of "Mexican overdrive" on our long car trips!

 

[air]

That's probably okay. Another possible option might be to see if there are any 240V, L2 charge stations near you. In NY, and probably other states, there are still some L2 stations that are both free parking and free charging (often at libraries, colleges, local parks, and municipal buildings). You can look for stations on any of the many Apps, "Plugshare" is a good one (some indicate outdated information for their local area, while it is up to date for other areas). I guess our ID.4 will have a built in database of charge stations too.

Some free charge stations are just one or two plugs and more in demand. However, there is a municipal building not far from me with a row of something like 10 free L2 chargepoint stations. I have never seen more than two cars there at a time.

Just an option to consider. Even with the best L2, it will be a longer charge time; maybe even drop the car off and go pick it up four+ hours later.

Yep, I downloaded plugshare over the holidays and have browsed around for some nearby free charging to supplement and/or maximize the 3yr free EA fast charging.