Modular battery pack design

[MountainDad]

Design the battery system for maintainability/upgradeability.

Battery modules (groups of cells) should be individually replaceable and the entire battery pack should be designed to minimize the effort necessary to replace it.

This would ensure these vehicles will remain viable into their 2nd and beyond lives, and be able to leverage inevitable improvements in battery tech over time.

 

[MountainDad]

I see where the OP is going with this and normally I'd be all for it. Bring back replacable phone batteries!!

But for a lot of what's been said already, the practicality starts to go out the door. I'd imagine the battery pack and compartment needs to be very precise to handle all the rough terrain these vehicles will handle. So making it more general may in fact start to have a safety risk involved.

I'd argue that the effort and research money should go into the actual recycling process than making it user swappable.

Its not that hard - Jaguar did it, but there isn't a recycling model that works, and the I-Pace isn't old enough to need it.

However, they did have a recall that required some batteries to be replaced (these were Panasonic batteries I believe...don't quote me though), so that may have made a difference for the automaker.

User replaceable batteries aren't practical at the moment - they're way too heavy, and you can't get them at AutoZone.

There are several auto battery recycling startups - automakers like Toyota, GM, and Ford are investing in this tech as well as private venture capital. If Scout was to develop the standards and engineering practices for designing and servicing modular batteries, they could license that tech to many providers as an additional source of revenue, and recover some of that engineering cost.

 

[TaconicBear]

All the ideas here have some merit, and the concerns and difficulties shared are equally meritorious. But I wonder if it is all moot. We keep hearing about new battery technologies that promise more charge density, and less reliance on scarce minerals. While it is hard to distinguish between the hype and speculations of YouTube hucksters vs. the realities of research, it does seem likely that by the time our EV Scouts roll out the door we may be welcoming a wholly new chemistry and technology. (If not then, it shan't be too far in the future.)

One would hope that one of the highest design goals will to assure that the vehicles which do catch fire (no matter the cause) will not turn into an unstoppable inferno. We are faced with advice from electricians to install home chargers 20+feet from a dwelling, fire companies that respond to Lithium fires only to prevent spreading, and regulations banning scooter and bike batteries from dwellings, etc. Anti-fire provisions should be a high priority in developing the batteries of the future.

 

[SpaceEVDriver]

The cell chemistry Scout will use will have at least 2000 charge cycles before it's degraded to 80% capacity. That's full 100%-0%-100% per cycle. A week of 50 miles per day, or something like 80% to 66% to 80% per day (14% per day, 7 days = 98%; round to 100%) is one full cycle.

A battery with 2000 cycle "lifetime" to 80% of capacity and going through 1 cycle per week is a 38.5 year battery (2000 cycles/life ÷ 52 weeks/year = 38.5 years/life).

Take some road trips with several cycles per trip and you might reduce that to a 30 year battery. Recognize that 80% state of health is still 280 miles range and keep driving for another 10-20 years (degradation is fastest early in the life of the battery). The battery is a 40 year part that only needs occasional preventative maintenance (coolant flush, analysis, and replacement about every 100k to 200k miles).

Barring catastrophic failure and defects in manufacturing on individual cells, modules, or batteries, most Scout batteries will be around longer than the rest of the vehicles.

Reducing complexity, increasing safety to the certified technicians, and reducing cost are more important than (and contrary to) making the battery user-serviceable. Just like replacing the power plant and drive train in a 1970s Scout isn't possible for most people, replacing the battery or one of its modules will only be possible for people with the proper training and tools.

 

[CarTechGeek]

The cell chemistry Scout will use will have at least 2000 charge cycles before it's degraded to 80% capacity. That's full 100%-0%-100% per cycle. A week of 50 miles per day, or something like 80% to 66% to 80% per day (14% per day, 7 days = 98%; round to 100%) is one full cycle.

Scout will most likely be using VW PowerCo (Assuming they don't fail like Northvolt) cells which will be made in several different types eventually.

But the initial ones will almost certainly be standard NMC (whether sourced from PowerCo or not), with ~1000 cycle life. Basically the same chemistry as 90% of long range packs in use.

 

[ID_ENG]

My concern is theoretical values versus real life values. Look at how many posts you see about Tesla battery replacements. There is a real chance, likely or not that you may have to replace the battery within a normal ownership lifecycle of the vehicle.

I would like to see what SM has as an offcial option for a replacement if or when the time comes.

Even if they say well at current prices, it'll be a $XX,XXX cost. At least it's something, and will help me decide to make an informed decision.

 

[SpaceEVDriver]

My concern is theoretical values versus real life values. Look at how many posts you see about Tesla battery replacements. There is a real chance, likely or not that you may have to replace the battery within a normal ownership lifecycle of the vehicle.

I would like to see what SM has as an offcial option for a replacement if or when the time comes.

Even if they say well at current prices, it'll be a $XX,XXX cost. At least it's something, and will help me decide to make an informed decision.

It's not theoretical.
The real-world lifetime is about 40% more than the theoretical lifetime--batteries last about 1.4x as long as predicted by laboratory studies.

Posts on car forums are far more about the very few people complaining or looking for help; it's not the vast majority of people without problems saying something like.
"Month 45: No new battery needed."
.
.
.
"Month 52: No new battery needed."
.
.
.
"Month 240: No new battery needed."

Existing EV batteries may last up to 40% longer than expected

Consumers’ real-world stop-and-go driving of electric vehicles benefits batteries more than the steady use simulated in almost all laboratory tests of new battery designs, Stanford-SLAC study finds.

news.stanford.edu

"Consumers’ real-world stop-and-go driving of electric vehicles benefits batteries more than the steady use simulated in almost all laboratory tests of new battery designs, Stanford-SLAC study finds."

 

[CarTechGeek]

It's not theoretical.
The real-world lifetime is about 40% more than the theoretical lifetime--batteries last about 1.4x as long as predicted by laboratory studies.

Cycle life wear was already not a concern, IMO.

A decent rule of thumb:

for NMC cells is about 1000 x pack range = pack life.
for LFP cells is about 2000 x pack range = pack life.

With 250 mile pack, that's 250,000 miles for NMC and 500,000 miles for LFP! Plus the pack is NOT dead then, that's the 80% capacity projection. They would still be ~200 mile packs.

I put less than 10K miles/year on a car, so my concern is not battery wearing out. If it was simply cycle life wear it would be a total non issue. Those 250 mile packs, would be 25+ year, and 50+ year packs for me.

So, my concern is not cycle life wear, it's being one of the unlucky ones with some kind cell failures.

It's usually the cell failures that take out packs, not cycle life wear, but all the focus seems to be on cycle life wear.

Until we have long term demonstration that cell failure are essentially a thing of the past, I want some kind of modular design, where bad cells can be replaced for a fraction of the whole pack cost.

 

[SpaceEVDriver]

So, my concern is not cycle life wear, it's being one of the unlucky ones with some kind cell failures.

It's usually the cell failures that take out packs, not cycle life wear, but all the focus seems to be on cycle life wear.

Until we have long term demonstration that cell failure are essentially a thing of the past, I want some kind of modular design, where bad cells can be replaced for a fraction of the whole pack cost.

It's very clear from the actual data that battery issues are basically a thing of the past. Chevy's Bolt fire recall was the biggest safety issue and has basically been eliminated. Nissan's poor thermal management failure with the Leaf was a lesson learned by pretty much all manufacturers.

Fewer than 1% of EVs sold since 2016 have had their batteries replaced. And of all BEVs sold in the US since 2011, only 2.5% have had their batteries replaced. For an essentially new technology, that's a a pretty good success rate and a great timeline. And that failure rate is decreasing every year as battery technology lessons are being applied to new batteries.

New Updates: How Long Do Electric Car Batteries Last?

We get a lot of questions from our community about electric car batteries. That is partly because the cost of battery replacement is so high (more on that later), but it is also due to limited information.

www.recurrentauto.com

In 2024, NHTSA has participated in 28,651 recalls. Of those, 34 have been High Voltage Battery related, which is 0.12% of the recalls and accounts for 0.04% of the vehicles subjected to recalls (BEVs account for 1% of light vehicles registered in the US, so the per-capita major recall is lower in this instance). Of the total recalls, >10% (2891) have been gasoline or diesel engine or fuel system related, and about 10.5% of the vehicles recalled have been recalled for engine or fossil fuel system recalls.

Department of Transportation - Recalls Data

About the Data: The dataset includes recall information related to specific NHTSA campaigns. Users can filter based on characteristics like manufacturer and component. The...

catalog.data.gov

Scout will build their batteries in a modular fashion, but single cell replacement at a service center is not going to happen--it's too dangerous. The service center will replace a module and then send the module with a bad cell back to SM to be refurbished. That refurbished module will either be put into rotation with an updated warranty or will otherwise be put back into use. The bad cell will be recycled.

 

[CarTechGeek]

Fewer than 1% of EVs sold since 2016 have had their batteries replaced. And of all BEVs sold in the US since 2011, only 2.5% have had their batteries replaced. For an essentially new technology, that's a a pretty good success rate and a great timeline. And that failure rate is decreasing every year as battery technology lessons are being applied to new batteries.

New Updates: How Long Do Electric Car Batteries Last?

We get a lot of questions from our community about electric car batteries. That is partly because the cost of battery replacement is so high (more on that later), but it is also due to limited information.

www.recurrentauto.com

From your link:

For cars older than 2015, replacement rates are 13%,

IMO, That's completely unacceptable. The whole issue is older, out of warranty battery replacement costs.

I wouldn't want to be near an out of warranty EV with ~10% chance it's going to need a full battery replacement, which likely devalues it to zero.

You can't claim new packs have it solved, because we won't know their status until they are also 10+ years old.

Scout will build their batteries in a modular fashion, but single cell replacement at a service center is not going to happen--it's too dangerous.

I'm not expecting cell replacement. If they can replace a module at say 10% the cost of replacing a pack that's good enough to mitigate risk.

Things of concern are cell-to-pack to designs. They are more efficient, but then you are stuck with cell level repairs which won't be officially done, so it's replacement packs or back alley repair. Or definitely whole pack if it's a glued in mass like the Tesla "structural" packs.

Cell-to-Module, and then Module-to-Pack, should enable official field repairs by replacing a module that contains faulty cells.

 

[ID_ENG]

I think @CarTechGeek hit the nail on what my actual concern is. The anomaly bad cell, that in turn requires a premature battery replacement.

I just can't take, these are issues of the past to the bank.

If battery life cycle hits somewhere like 500k miles (just throwing a number out there from posts).
And the chance of faulty cells are slim.

I'd love to see a warranty from SM, for full battery replacement for clear issues of sub 80% battery capacity or faulty cells, or anything of that matter for batteries with vehicle range less than that 500k figure.

Of course warranty would be void of physical damage and neglect and all that. And warranty should be passed from owner to owner.

 

[SpaceEVDriver]

I think @CarTechGeek hit the nail on what my actual concern is. The anomaly bad cell, that in turn requires a premature battery replacement.

I just can't take, these are issues of the past to the bank.

If battery life cycle hits somewhere like 500k miles (just throwing a number out there from posts).
And the chance of faulty cells are slim.

I'd love to see a warranty from SM, for full battery replacement for clear issues of sub 80% battery capacity or faulty cells, or anything of that matter for batteries with vehicle range less than that 500k figure.

Of course warranty would be void of physical damage and neglect and all that. And warranty should be passed from owner to owner.

The only company that I'm aware of that isn't making all of their batteries modular is brand-T, for one of their newer batteries. Brand-T has started moving toward single-module, one-piece structural batteries, along with giant cast parts that must be replaced after an accident. They're moving toward making their cars very expensive disposable items. Scout is going the opposite: serviceability. The former is cheaper for the manufacturer, but renders the car useless (or very, very expensive) after an accident or manufacturing defect. The latter is better for everyone.

All EVs sold in the US are required to have a warranty on the HVB, but I wouldn't hold my breath for a warranty that lasts much longer than required by law. I would hope they would say 10 years/150,000 miles, but would be surprised if they went further than that. They're not designing and building the batteries themselves, so they would be stuck with a warranty on a product that they're not in control of.

Federal Register :: Request Access

Batteries installed in light-duty program vehicles must meet a Minimum Performance Requirement such that measured usable battery energy is at least 80 percent of the vehicle's certified usable battery energy after 5 years or 62,000 miles, and at least 70 percent of certified usable battery energy at 8 years or 100,000 miles.

 

[CarTechGeek]

The only company that I'm aware of that isn't making all of their batteries modular is brand-T, for one of their newer batteries.

This video has an excellent overview of multiple cell and pack types. I have a time stamp where he discusses the Structural pack ("now it's all one big piece of disposable Hardware"):

 

[R1TVT]

Warranties on EV purchases can be a critical aspect for building consumer confidence - especially for a "new" vehicle that is being built by essentially a brand new company. I would give Scout the benefit of the doubt and wait to see what the warranty will look like before freaking out. I'm guessing that the warranty will be quite excellent. They also have industry benchmarks that have been set high. Think about the warranty you have on your current vehicle, then compare that to where Scout eventually lands on their warranty.

I would not have considered the purchase of a Launch Edition R1T without this. 8 years / 175,000 miles is pretty great IMHO. Battery capacity is set to at least 70% of its original capacity over that same time frame. For reference, I have 40,000 miles on my 2022 R1T and have seen virtually no capacity loss on the battery.

 

[THil08]

Scout will probably be using PowerCo as the battery supplier and there cells look like they will be easy to replace compared to the cells used today.

And most battery packs today are modular that make up one large pack.

 

[CarTechGeek]

Scout will probably be using PowerCo as the battery supplier and there cells look like they will be easy to replace compared to the cells used today.

And most battery packs today are modular that make up one large pack.

Hopefully PowerCo works out better than Northvolt.

 

[THil08]

Hopefully PowerCo works out better than NorthVolt.

PowerCo has Quantum Scape behind them along with VW. And they are building a few giga factories that are ready to produce this year 2025 at a high volume but not at full scale. Probably to test the product out. So they should be highly successful.

NorthVolt decided to get fancy all of a sudden when Volvo(owned by Geely) joined with them, they decided to make an extra factory. But thats what happens when communist(sorry for that word but thats what they are just trying to be politically correct) China takes control of a company that would have been highly successful by it self.

 

[CarTechGeek]

PowerCo has Quantum Scape behind them along with VW. And they are building a few giga factories that are ready to produce this year 2025 at a high volume but not at full scale. Probably to test the product out. So they should be highly successful.

NorthVolt decided to get fancy all of a sudden when Volvo(owned by Geely) joined with them, they decided to make an extra factory. But thats what happens when communist(sorry for that word but thats what they are just trying to be politically correct) China takes control of a company that would have been highly successful by it self.

I'm not seeing the Geely really having anything to do with the downfall at all, and not China takeover. They did have to keep bringing in Chinese experts to try to fix their process, but that's hardly a takeover.

And how is PowerCo building multiple factories a good thing, but NorthVolt building an exta factory a bad thing?

BTW the biggest corporate shareholder in Northvolt is VW...

 

[THil08]

I'm not seeing the Geely really having anything to do with the downfall at all, and not China takeover. They did have to keep bringing in Chinese experts to try to fix their process, but that's hardly a takeover.

And how is PowerCo building multiple factories a good thing, but NorthVolt building an exta factory a bad thing?

BTW the biggest corporate shareholder in Northvolt is VW...

PowerCo is making multiple different types of cells. and just so everyone knows they don’t have multiple factories, one is a research facility in Germany, and the one in Canada will be producing the production cells. Barcelona is a test facility. And besides that VW and PowerCo are renting out space in those facilities. So yes that’s why PowerCo having multiple locations is good.

And NorthVolt has had problems since they started I’ll list them

- not focusing on one thing at a time

- Horrible Cell Design and structure

- supply chain issues

- quality issues (BMW had to replace over 2 billion dollars of batteries in cars that they supplied)

- Noting being able to keep with competitors

I’ve done my research on this topic back when BMW had issues with them.

 

[ID_ENG]

PowerCo has Quantum Scape behind them along with VW. And they are building a few giga factories that are ready to produce this year 2025 at a high volume but not at full scale. Probably to test the product out. So they should be highly successful.

NorthVolt decided to get fancy all of a sudden when Volvo(owned by Geely) joined with them, they decided to make an extra factory. But thats what happens when communist(sorry for that word but thats what they are just trying to be politically correct) China takes control of a company that would have been highly successful by it self.

Just did a quick google on QuantumScape. This is exactly what was holding me back from pure EV. That is until the Harvester announcement took me by surprise and enrolled in the early reservation thing.

Having the Harvester AND solid state batter .....SM please make it so!