3 ms·

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 comfor

by 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?

by acyou 2y ago

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?