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Lithium ion batteries and battery modules are never ever gonna be user repairable. The main reason is that the electrolyte is a highly toxic, carcinogenic and e

by acyou 2y ago

Lithium ion batteries and battery modules are never ever gonna be user repairable. The main reason is that the electrolyte is a highly toxic, carcinogenic and extremely flammable organic solvent. AAs are user swappable because the electrolyte is water based. Bikes started being less repairable when manufacturers noticed that steel frame 10 speeds were lasting multiple decades. If parts continue to be available, those frames are still going to be in use another 50 years from now. Particularly where cartridge bearings are used. Carbon fiber bikes are part of the trend. Will we eventually see a straight up plastic adult bike frame?

woah 2y ago
AAs aren't user repairable either. When was the last time you repaired an AA? What the article is asking for is just a standardized connector and voltage for Li-ion batteries.
- acyou 2y ago
  I misspoke, what I intended to say is that lithium ion batteries are never going to be user swappable. Yes, you can get sketchy stuff off of Amazon that supports it, but the regulatory bodies will, correctly, continue to strongly resist end users touching bare lithium ion cells. Ever drop an AA battery? Nothing happens. Drop an 18650, you can easily have a little 1000 degree rocket shooting fire and toxic chemicals out one end. Nominal cell voltage is fairly standard and is dictated by cell chemistry. Standardized connector is welded zinc tab, for various good safety reasons.
oulipo 2y ago
Check out what we're building at https://get.gouach.com https://get.gouach.com ! We're solving exactly this problem, and we have designed a fireproof casing for extra safety! Happy to answer any question :)
- acyou 2y ago
  I could see this being interesting if you handle all the aspects of pack teardown, rebuild and recertification, and send out finished packs. Would you be comfortable with doing that and standing behind those 100%? Asking regular people or even highly technical people to assess cell geometry, type, quality, balancing and cell capacity issues is going to result in people dying in fire. It just isn't that easy, even if you start with brand new, matched cells. Fireproof casing sounds great, as long as it's also being charged in a fireproof bunker. Unfortunately, that's not usually the case for consumer products. Noticing that in the video of the cell vent testing - Bosch vs. Gouach the electrical wire harness immediately turns black. If you charge this pack in a box filled with paper and a cell vents, will it start a fire? How are you going to thoroughly test with your production parts before shipping to customers next month?
  - oulipo 2y ago
    Thanks for all those questions! No we will ship standard cells that we tested the battery with (it is EU-certified, and UL-certification is ongoing) Yes! The battery is quite safe now! We have iterated on the design for close to 4 years now. We have added safeties everywhere so that even a misplaced cell wouldn't be dangerous. And as you mention the fireproof casing is the extra layer of safety, so that if there is an unlikely thermal event, no flames can go out. We've been running those batteries for around 2 years on about 1000 shared mobility e-bikes in France, so we're quite sure of the design!
    - acyou 2y ago
      That's great to hear. UL certification is a starting point. How is that going? What does EU-certified mean with regards to battery safety? I think the sticking point with UL is that you need to know the specific application in order to assess the downstream risks. Are you able to do the UL certification for multiple bikes, or just a specific model? Are you able to get UL certification for multiple different cell brands, or do you need to do a different certification for each type of cells used in the pack? I'm assuming mixed salvaged cells are off the table for UL certification?
userbinator 2y ago
Lion cell electrolytes are nowhere near as toxic as those of NiCd or lead-acid. Flammability is the biggest risk. Toxicity is comparable to acetone. https://en.wikipedia.org/wiki/Propylene_carbonate https://en.wikipedia.org/wiki/Propylene_carbonate https://en.wikipedia.org/wiki/Diethyl_carbonate https://en.wikipedia.org/wiki/Diethyl_carbonate https://en.wikipedia.org/wiki/Ethyl_acetate https://en.wikipedia.org/wiki/Ethyl_acetate
- acyou 2y ago
  Yes, but unless you drink the lead acid battery acid, you're not exposed to it. Ditto for NiCd. No one is drinking battery electrolyte. The key is that all of the above in Lithium ion are VOC and highly available, including what you mentioned and worse, specifically NMP.
  - allenrb 2y ago
    People are talking about replacing cells within packs, not disassembling the cells themselves!
    - acyou 2y ago
      Agreed, I apologize that I wasn't more clear. It's just that the electrolyte composition forms the basis of safety. In an environment where end users are handling bare cells, you need to assume the cells are leaky/ruptured. For example, if you have ever changed out old Duracell alkaline batteries, the white stuff on the contacts means they leaked.
  - userbinator 2y ago
    "In the US, propylene carbonate is not regulated as a volatile organic compound (VOC) because it does not contribute significantly to the formation of smog and because its vapor is not known or suspected to cause cancer or other toxic effects" "Diethyl carbonate is used as a solvent such as in erythromycin intramuscular injections." Ethyl acetate: "The LD50 for rats is 5620 mg/kg,[24] indicating low acute toxicity. Given that the chemical is naturally present in many organisms, there is little risk of toxicity."
derkades 2y ago
At least standardized form factors and no complex proprietary communication protocols to the battery would help a lot to make battery replacements more affordable
mschuster91 2y ago
> Bikes started being less repairable when manufacturers noticed that steel frame 10 speeds were lasting multiple decades. Steel frames are heavy beasts. Aluminum alloys, magnesium alloys or carbon fiber is waaaay lighter in contrast, and weight is king at least if you're not running with electrical assistance. It's exactly the same in cars, there we have exactly the same trend towards lighter but more brittle materials.
- AdrianB1 2y ago
  I used to race as an amateur for almost 10 years. I saw people winning on steel frame bikes and for flat terrain the weight of the bike is not that important. Carbon is light indeed, but the frame as a percent of the overall bike can be quite low, as low as 25%. Half a kilo in a 12 kg MTB is insignificant except pro races.
  - mschuster91 2y ago
    I'm not necessarily talking about bike races... for commuter bikes that you have to lug up and down stairs into your basement, every gram counts. My e-bike is somewhat around 20 kg, that thing is a tank in its own right, and it's hell to haul around when our beloved Deutsche Bahn once again manages to fuck up elevators.

by acyou 2y ago

woah 2y ago

AAs aren't user repairable either. When was the last time you repaired an AA? What the article is asking for is just a standardized connector and voltage for Li-ion batteries.

acyou 2y ago
I misspoke, what I intended to say is that lithium ion batteries are never going to be user swappable. Yes, you can get sketchy stuff off of Amazon that supports it, but the regulatory bodies will, correctly, continue to strongly resist end users touching bare lithium ion cells. Ever drop an AA battery? Nothing happens. Drop an 18650, you can easily have a little 1000 degree rocket shooting fire and toxic chemicals out one end. Nominal cell voltage is fairly standard and is dictated by cell chemistry. Standardized connector is welded zinc tab, for various good safety reasons.

oulipo 2y ago

Check out what we're building at https://get.gouach.com https://get.gouach.com ! We're solving exactly this problem, and we have designed a fireproof casing for extra safety! Happy to answer any question :)

acyou 2y ago
I could see this being interesting if you handle all the aspects of pack teardown, rebuild and recertification, and send out finished packs. Would you be comfortable with doing that and standing behind those 100%? Asking regular people or even highly technical people to assess cell geometry, type, quality, balancing and cell capacity issues is going to result in people dying in fire. It just isn't that easy, even if you start with brand new, matched cells. Fireproof casing sounds great, as long as it's also being charged in a fireproof bunker. Unfortunately, that's not usually the case for consumer products. Noticing that in the video of the cell vent testing - Bosch vs. Gouach the electrical wire harness immediately turns black. If you charge this pack in a box filled with paper and a cell vents, will it start a fire? How are you going to thoroughly test with your production parts before shipping to customers next month?
- oulipo 2y ago
  Thanks for all those questions! No we will ship standard cells that we tested the battery with (it is EU-certified, and UL-certification is ongoing) Yes! The battery is quite safe now! We have iterated on the design for close to 4 years now. We have added safeties everywhere so that even a misplaced cell wouldn't be dangerous. And as you mention the fireproof casing is the extra layer of safety, so that if there is an unlikely thermal event, no flames can go out. We've been running those batteries for around 2 years on about 1000 shared mobility e-bikes in France, so we're quite sure of the design!
  - acyou 2y ago
    That's great to hear. UL certification is a starting point. How is that going? What does EU-certified mean with regards to battery safety? I think the sticking point with UL is that you need to know the specific application in order to assess the downstream risks. Are you able to do the UL certification for multiple bikes, or just a specific model? Are you able to get UL certification for multiple different cell brands, or do you need to do a different certification for each type of cells used in the pack? I'm assuming mixed salvaged cells are off the table for UL certification?

userbinator 2y ago

Lion cell electrolytes are nowhere near as toxic as those of NiCd or lead-acid. Flammability is the biggest risk. Toxicity is comparable to acetone. https://en.wikipedia.org/wiki/Propylene_carbonate https://en.wikipedia.org/wiki/Propylene_carbonate https://en.wikipedia.org/wiki/Diethyl_carbonate https://en.wikipedia.org/wiki/Diethyl_carbonate https://en.wikipedia.org/wiki/Ethyl_acetate https://en.wikipedia.org/wiki/Ethyl_acetate

acyou 2y ago
Yes, but unless you drink the lead acid battery acid, you're not exposed to it. Ditto for NiCd. No one is drinking battery electrolyte. The key is that all of the above in Lithium ion are VOC and highly available, including what you mentioned and worse, specifically NMP.
- allenrb 2y ago
  People are talking about replacing cells within packs, not disassembling the cells themselves!
  - acyou 2y ago
    Agreed, I apologize that I wasn't more clear. It's just that the electrolyte composition forms the basis of safety. In an environment where end users are handling bare cells, you need to assume the cells are leaky/ruptured. For example, if you have ever changed out old Duracell alkaline batteries, the white stuff on the contacts means they leaked.
- userbinator 2y ago
  "In the US, propylene carbonate is not regulated as a volatile organic compound (VOC) because it does not contribute significantly to the formation of smog and because its vapor is not known or suspected to cause cancer or other toxic effects" "Diethyl carbonate is used as a solvent such as in erythromycin intramuscular injections." Ethyl acetate: "The LD50 for rats is 5620 mg/kg,[24] indicating low acute toxicity. Given that the chemical is naturally present in many organisms, there is little risk of toxicity."

derkades 2y ago

At least standardized form factors and no complex proprietary communication protocols to the battery would help a lot to make battery replacements more affordable

mschuster91 2y ago

> Bikes started being less repairable when manufacturers noticed that steel frame 10 speeds were lasting multiple decades. Steel frames are heavy beasts. Aluminum alloys, magnesium alloys or carbon fiber is waaaay lighter in contrast, and weight is king at least if you're not running with electrical assistance. It's exactly the same in cars, there we have exactly the same trend towards lighter but more brittle materials.

AdrianB1 2y ago
I used to race as an amateur for almost 10 years. I saw people winning on steel frame bikes and for flat terrain the weight of the bike is not that important. Carbon is light indeed, but the frame as a percent of the overall bike can be quite low, as low as 25%. Half a kilo in a 12 kg MTB is insignificant except pro races.
- mschuster91 2y ago
  I'm not necessarily talking about bike races... for commuter bikes that you have to lug up and down stairs into your basement, every gram counts. My e-bike is somewhat around 20 kg, that thing is a tank in its own right, and it's hell to haul around when our beloved Deutsche Bahn once again manages to fuck up elevators.