Ultium: DCFC to 100%, no degradation

1846 Views 15 Replies 8 Participants Last post by obermd, 2 mo ago

Steverino

Discussion Starter · 6 mo ago

There's been discussion about whether the new Ultium batteries should be charged less than 100% on DCFC, and whether to limit the number of DC fast charges to avoid battery degradation. The common advice has been to avoid both to avoid prematurely aging the battery.

GM's Tim Grewe is saying neither are an issue with the Ultium batteries, so charge away without worry:

Tim Grewe, GM's global electrification and battery systems director, makes some bold claims for the Ultium pack. He says no amount of DC fast-charging will degrade its capacity, and unlike Tesla and others, GM will not suggest the pack be charged to less than 100 percent during normal daily use. He credits the breakthrough to the careful development of the chemistry, including the addition of aluminum into the cell. Grewe also promises that the Ultium pack "will last longer than the Bolt EV's," which he says is making it to between 150,000 and 250,000 miles in the real world, comfortably past its 100,000-mile warranty.

www.caranddriver.com

How GM's Ultium Battery Will Help It Commit to an Electric Future

An inside look at the new battery powering General Motors' electric future.

www.caranddriver.com

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MaybeFutureBuyer

· #2 · 6 mo ago

For me, it's not about the miles, it's about the time. Most lithium batteries shouldn't be stored at 100% capacity. I wonder if this is something GM has solved as well.

It doesn't matter to me that much, because even keeping it on 80% is good enough for 99.8% of my drives (I drive over 200 Km round trip once every 2-3 years)... But it will still be interesting to know.

EVolution

· #3 · 6 mo ago

I doubt they have solved this issue. Instead, they are probably relying on the modular capabilities of the packs in the Ultium platform knowing that if there are warranty claims due to degradation they can replace packs rather than the whole battery to keep the costs down.

Mapleev

· #4 · 6 mo ago

If it is true, it would be good news for those who do not have a home charging system and rely on fast chargers. They can charge it to 100% each time and visit fast chargers fewer times.

it will also make it simple for people with home chargers, you charge it to 100% each time and if you have a surprise longer drive, you will have the extra range.

EVolution

· #5 · 6 mo ago

Mapleev said:
If it is true, it would be good news for those who do not have a home charging system and rely on fast chargers. They can charge it to 100% each time and visit fast chargers fewer times.

it will also make it simple for people with home chargers, you charge it to 100% each time and if you have a surprise longer drive, you will have the extra range.

From what I gather most who use fast chargers tend to only charge to 80% not 100% more due to the charging curve than the degradation. If a 20-30 min charge is going to turn into 60 min or more most people are just going to hang it up at 80%.

Reactions: 3

hellsop

· #6 · 6 mo ago

EVolution said:
From what I gather most who use fast chargers tend to only charge to 80% not 100% more due to the charging curve than the degradation. If a 20-30 min charge is going to turn into 60 min or more most people are just going to hang it up at 80%.

If even that high. Bolt charge rate starts tapering at about 60%, and if you're paying by the minute, the price per mile starts climbing then.

MaybeFutureBuyer

· #7 · 6 mo ago

hellsop said:
If even that high. Bolt charge rate starts tapering at about 60%, and if you're paying by the minute, the price per mile starts climbing then.

What's all that "paying by the minute" crap they pull? It should be "per kWh". I don't pay by the minute to my electricity provider. It should be "by the minute" when you're fully charged (so, pretty much paying for blocking the charger), and "by kWh" as long as you're charging!

And if it's a problem because it's trickle at the last 5%-10%, then "by the minute" when the rate of charging guess under a certain point (let's say 50% below max rate).

Reactions: 1

Steverino

Discussion Starter · #8 · 6 mo ago

MaybeFutureBuyer said:
What's all that "paying by the minute" crap they pull? It should be "per kWh".

Not sure about Canada, but in the States only power companies lcan charge by the amount used, So...everyone else is forced to charge by time. Maybe there are some states that allow other to charge by the amount used but I think that pushes them into "public utility" regulations just like a power plant.

MaybeFutureBuyer

· #9 · 6 mo ago

Steverino said:
Not sure about Canada, but in the States only power companies lcan charge by the amount used, So...everyone else is forced to charge by time. Maybe there are some states that allow other to charge by the amount used but I think that pushes them into "public utility" regulations just like a power plant.

Gas stations are allowed to do it, so why can't the chargers? It will be much easier for them as well (financial), because they pay by the kWh... So they'll know their margins better.

Mapleev

· #10 · 6 mo ago

Steverino said:
Not sure about Canada, but in the States only power companies lcan charge by the amount used, So...everyone else is forced to charge by time. Maybe there are some states that allow other to charge by the amount used but I think that pushes them into "public utility" regulations just like a power plant.

I have no personal experience, but every company I researched on line, I saw that they charged by the minute and how much was charged per minute varied by Company and the charging speed.

obermd

· #11 · 6 mo ago

Steverino said:
Not sure about Canada, but in the States only power companies lcan charge by the amount used, So...everyone else is forced to charge by time. Maybe there are some states that allow other to charge by the amount used but I think that pushes them into "public utility" regulations just like a power plant.

The charging networks need to start charging by the KWh and when the government says they can't do that point out that they're fueling motor vehicles. There's an exemption for fuel oil in various forms. In this case electricity is a fuel.

Reactions: 1

hellsop

· #12 · 6 mo ago

Steverino said:
Not sure about Canada, but in the States only power companies can charge by the amount used, So...everyone else is forced to charge by time. Maybe there are some states that allow other to charge by the amount used but I think that pushes them into "public utility" regulations just like a power plant.

California and a couple of other states (12? 17? something like that) allow billing by kwh other than by public utilities. Most states make it impossible, whether directly by statute or indirectly by some technical requirement for metering that's difficult or annoying to implement on a DCFC. I'm not familiar with all the different rules, though. I'd imagine that the charging network operators probably kind of like the time-based option as it encourages people to move on and free up a head which aid in them meeting the demand for capacity a little easier.

Nebula1701

· #13 · 6 mo ago

hellsop said:
California and a couple of other states (12? 17? something like that) allow billing by kwh other than by public utilities. Most states make it impossible, whether directly by statute or indirectly by some technical requirement for metering that's difficult or annoying to implement on a DCFC. I'm not familiar with all the different rules, though. I'd imagine that the charging network operators probably kind of like the time-based option as it encourages people to move on and free up a head which aid in them meeting the demand for capacity a little easier.

For some Vehicles Time Based Charging is much cheaper than if they were doing it by kWh.

MaybeFutureBuyer

· #14 · 6 mo ago

Nebula1701 said:
For some Vehicles Time Based Charging is much cheaper than if they were doing it by kWh.

Yes. And that isn't really fair. Imagine that both of us are going to the gas station and fueling the same amount, but you pay double what I do. You punish the other with less advanced EVs, which are usually the less-rich people.

Reactions: 1

threeputts

· #15 · 2 mo ago

I realize this thread is from a few months ago but wanted to clarify that it’s state not federal laws that determine if electricity is sold by kWh or by time. Some states allow by the kWh and some dont.

Reactions: 4

obermd

· #16 · 2 mo ago

threeputts said:
I realize this thread is from a few months ago but wanted to clarify that it’s state not federal laws that determine if electricity is sold by kWh or by time. Some states allow by the kWh and some dont.

I think the solution is to declare that commercial EVSE systems will be regulated and use the same pricing model as gas pumps. When electricity is consumed by an EVSE it's a motor fuel.

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