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Discussion Starter #1
Is there such a thing as a possibility of designing a BEV such that over time, as the pack ages in years and miles, individual cells and modules can be replaced if needed, rather than just the whole pack? I guess there's also a related topic or question of what sort of fault-tolerance and transparency the pack has for the driver, so they can get to service before the vehicle starts giving signs of issues.

I'm told there may be engineering challenges in trying to devise a pack such that cell and module replacement is more do-able, but from a business standpoint, it would seem to be a no-brainer for competing manufacturers at least to try to design such a thing. Replacing a cell or module might well help keep manufacturer in-warranty costs low, and help drivers keep their past-warranty costs of ownership low. Perhaps it would also help overall driver satisfaction.

At present the few manufacturers that have offered decent long-range BEVS in the US seem to insist on an all-or-nothing approach to pack replacement, though I don't have full information, and maybe this is not exactly right.
 

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I thought module replacement already is the norm. (I say "the norm" but battery issues aren't exactly common.)
 

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The question is where is it done - at the stealership or a central location. Consider the engine in an ICE - most stealerships replace the whole unit rather than repair it. It may be the same with battery packs.
 

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Cells may be troublesome to acquire that are similar size / standard. Even more complex is repairing electronics which can be tied up in coding - see threads on Ion/Zero/iMiev.
 

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Is there such a thing as a possibility of designing a BEV such that over time, as the pack ages in years and miles, individual cells and modules can be replaced if needed, rather than just the whole pack? I guess there's also a related topic or question of what sort of fault-tolerance and transparency the pack has for the driver, so they can get to service before the vehicle starts giving signs of issues.

I'm told there may be engineering challenges in trying to devise a pack such that cell and module replacement is more do-able, but from a business standpoint, it would seem to be a no-brainer for competing manufacturers at least to try to design such a thing. Replacing a cell or module might well help keep manufacturer in-warranty costs low, and help drivers keep their past-warranty costs of ownership low. Perhaps it would also help overall driver satisfaction.

At present the few manufacturers that have offered decent long-range BEVS in the US seem to insist on an all-or-nothing approach to pack replacement, though I don't have full information, and maybe this is not exactly right.
The BMW i3 design allows for individual cell replacement in the event of a warranty failure. The option to upgrade the whole battery from 60 to 120Ah is possible but it is not an offered option in the UK market.
 

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...designing a BEV such that over time, as the pack ages in years and miles, individual cells and modules can be replaced if needed, rather than just the whole pack? ...from a business standpoint, it would seem to be a no-brainer for competing manufacturers at least to try to design such a thing.
The opposite is true - there is no incentive on manufacturers to make cell replacement cheap or easy. They don't want 3rd parties to do it, they would rather you have to go back to the dealership where they have specialist tools and they can charge you such a high labour rate that they can sell you a new car instead. They want it to last only as long as the warranty period... They make much more money on a new car than on repairs - they would rather you keep the car for as short a period as possible, then come back and burn a load more money on depreciation.

That said, many cars do allow cell replacement without too much difficulty - the i-miev/c-zero/ion and Leaf are some. The batteries in the i-miev are certainly not cutting edge but on the flip side they are generally bullet proof, last a long time and replacement is easy - i've had a pack of out one of those on my drive. Individual cell replacement is not usually needed until 10+ years, and aside from odd bad cells the battery pack health is generally around 80% at this point.

Leaf battery packs suffer from multiple rapid charges (no temperature management, so they get hot) and it can affect all the cells. You can see on autotrader the cheap early Leafs - although you can swap cells, it isn't one or 2 bad cells, the capacity of all cells has been affected by temperature and charge rate and over time the capacity of all the cells has reduced. Cell swaps for Leafs are available and it can help capacity, but only really where you have a few bad cells rather than a whole pack.

The good news is that with a bigger battery pack the effect of usage is lessened - for example I have a 22kwh Zoe - if I do 10,000 miles that is 125 full battery cycles or 250 half cycles - if I upgraded to a 40kwh Zoe those same 10,000 miles would be about 70 full battery cycles, i.e. less work for the battery so I expect battery degradation to lessen with newer models. As time goes on more garages will be able to repair or replace battery packs, so battery swaps for refurbed packs will become more common. It is starting but it is a bit ad-hoc at the moment.

Cheers.
 

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Discussion Starter #9
The opposite is true - there is no incentive on manufacturers to make cell replacement cheap or easy.
[...]
This I have to disagree with. The incentive is that over time, as EV buyers become more sophisticated, they will recognize if some BEVS are very expensive and a hassle to keep in running order, and if others are very inexpensive and relatively hassle-free to keep in running order. Just as with fossil-fueled vehicles, the latter may (on balance) have some superior longevity in the used marketplace. Buyers may over time treat it as one positive buying factor when buying new, and when buying used they will take into account if a used BEV has a bad or good reputation for how difficult it will be to do deal with.

To be sure, I think it's fairly clear at this point in the established vehicle markets in the US, UK and many other countries that there is a certain "set in their ways" aspect of the dozens of established auto marques and their established distribution and service pathways. If the old ways still apply, for some of them it will not only be a matter of sticking with gasoline engines, but sticking with a certain amount of the widely-accepted expenses and hassles of keeping a vehicle running.

However, Tesla, the Chinese (including China-owned marques outside of China) and perhaps others are trying to survive and bring vigorous competition and change. They have an incentive (i.e. survival and profit) to recognize that there is potential for change not only with respect to powertrain technology, but in many other aspects of how customers are served and treated, including in vehicle service and maintenance. This incentive may not win out in a marketplace with entrenched well-financed companies set in the old ways, but it is there nonetheless.
 

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Discussion Starter #10
[...]

However, Tesla, the Chinese (including China-owned marques outside of China) and perhaps others are trying to survive and bring vigorous competition and change. They have an incentive (i.e. survival and profit) to recognize that there is potential for change not only with respect to powertrain technology, but in many other aspects of how customers are served and treated, including in vehicle service and maintenance. This incentive may not win out in a marketplace with entrenched well-financed companies set in the old ways, but it is there nonetheless.
I should add that while some of the old-style companies and their systems may seem geared toward an overly-expensive and hassle-filled service and maintenance process, most of them I suspect get, to one degree or another, the importance of working toward lower lifetime costs and hassles for the customers.
 

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I would assume a lot has to do with replacing new for old on an ageing pack. Causes all sorts of balancing issues so there is probably a big trade off in cost replacing then other issues after vs just swapping a new or used pack in.
 

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I would assume a lot has to do with replacing new for old on an ageing pack. Causes all sorts of balancing issues so there is probably a big trade off in cost replacing then other issues after vs just swapping a new or used pack in.
Yes. Replacing of cells in an old battery is akin to replacing one set of piston rings in an ICE engine. You'll just be doing another few/one in a couple of months time.
 

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Yes. Replacing of cells in an old battery is akin to replacing one set of piston rings in an ICE engine. You'll just be doing another few/one in a couple of months time.
Not necessarily, it depends on the situation - the BMS will stop the car when one cell gets to the minimum voltage - if you have a few bad cells and the rest are OK then swapping those bad cells for good used or new cells brings the pack up to the performance of the next weakest cell, which could be a lot better than the other bad ones. It really depends whether it is the whole pack that has degraded or just a few cells - if its only a few cells then cell swapping can give you years more motoring with good range.

This is what is happening with the early i-miev's, the cells overall degrade slowly over time other than a handful of cells, and swapping out those cells brings the pack up to a good performance. If it is complete pack replacement that is required then this can cause the car to be scrapped - early Leafs are being scrapped because all cells have degraded and there is no cheap replacement.

I still really dont think the old school manufacturers will have any reason to make EVs ultra reliable and easy to fix - their dealers will get less money for services with an EV and if they make it easy for 3rd parties to repair them then the dealers will get less money for repair as well....

Cheers.
 

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Not necessarily, it depends on the situation - the BMS will stop the car when one cell gets to the minimum voltage - if you have a few bad cells and the rest are OK
For a fairly new pack, e.g. in warranty, then I'd agree, especially since identical spares will probably be available and failures are likely to be 'left side' of the bathtub.
For old packs where you are dealing with the 'right side' of the bathtub, so more failures are likely to follow and at maybe 10 years old finding compatible spares may be difficult, then trying to replace odd cells seems to me to be a fool's errand. **

I still really dont think the old school manufacturers will have any reason to make EVs ultra reliable and easy to fix
I quite agree. AIUI they generally guarantee support for 10 years at present and I don't see that moving to EVs would suddenly make them change. Other influences might, but I wouldn't put money on it.

** I appreciate that there will always be a dedicated minority who will do this sort of thing because they can, as now with ICE. But for the average user/owner and commercial enterprise it won't work. It'll be a fully refurbed pack, as with a refurbed ICE at present.
 

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Is there such a thing as a possibility of designing a BEV such that over time, as the pack ages in years and miles, individual cells and modules can be replaced if needed, rather than just the whole pack?
BMW and Nissan both offer cell/module level replacement. This is done at a dealership that has the tools and a mechanic with specialist training.

Brand new modules for LEAF 24kWh battery are in short supply. Nissan are offering refurbished (good, used) modules. Here in the UK, 3rd party garages offer good used modules for both 24 and 30kWh packs.

BMW i3 94Ah pack with the cells visible. Nissan are similar but at a module level. Nissan modules are made up of stacks of pouch cells.

125253
 

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I see nothing in this thread about Volkswagen. I recently acquired a 2016 e-golf. I really like the car. If I can, I would like to keep it going for a long while. Is there any news about Volkswagen and their intentions regarding battery repair/replacement? Perhaps even third party interests.
 

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I recently acquired a 2016 e-golf. I really like the car. If I can, I would like to keep it going for a long while. Is there any news about Volkswagen and their intentions regarding battery repair/replacement? Perhaps even third party interests.
That generation e-Golf is a rare car in the UK. VW only sold a few hundred here. It may not have reached critical mass. If the manufacturer doesn't have an advertised repair program, someone has to buy a salvaged car, take the pack apart and post about it.

US market could be different.
 

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I see nothing in this thread about Volkswagen. I recently acquired a 2016 e-golf. I really like the car. If I can, I would like to keep it going for a long while. Is there any news about Volkswagen and their intentions regarding battery repair/replacement? Perhaps even third party interests.
Seems to me they fair pretty well until you get over the 100k+ mark. I’d imagine by then you would be better of swapping for a mid mileage newer model in years to come.
 

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I imagine the reality is it ends up much the same as old ICE cars. How many folk with a 8 or 10 year old car whose engine has failed, will goto the dealer and buy a new engine? Its far more likely they'd approach the used sector, and pick up a decent used engine from a dismantler, or maybe, goto a specialist who will strip and rebuild the engine.

The engines the dealer does sell are likely to be warranty jobs covering the odd freak failure on newer cars.

Batteries will surely follow the same model. No-one with an 8 year old leaf worth 6 grand, is going to buy a new battery from the dealer. they will either flog the car as is, to someone who can deal with the limited range, or they will source a good used pack and swap it out. Those good used packs are currently massively overpriced though.
 
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