• Jeena
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    402 months ago

    I mean there are quite many fires in China started by those e-bikes but I thought it was because of bad quality.

    • @rumba@lemmy.zip
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      432 months ago

      There are chemistries that are less volatile But they’re less energy dense as well.

      The biggest problem I see on most of the Chinese stuff is a lack of safety in the battery packs. They’re just mass-producing cells and shoving them together, It wouldn’t be very expensive to put a small battery management system on every cell. Watch each cell for voltage and temperature. Have them shut down when they’re out of safety margins

      • @ChaoticNeutralCzech@feddit.org
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        312 months ago

        LiFePO4 is still superior to traction lead-acid in pretty much every way: energy density, safety, time and cycle life, internal resistance… Yes, they need a BMS but those are very cheap and lots of batteries have them built-in. In fact, I was unable to find 4-cell packs without a BMS inside so I could put two of them in series and balance the 8S cells with each other using an active BMS of my choice, and ended up ordering individual cells and screwing them together.

        • @noride@lemm.ee
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          242 months ago

          Also worth mentioning LiFePO4 is like half the weight of lead acid and it’s far less susceptible to voltage sag under load. The only area I think LiFePO4 runs into challenges is the inability to charge below freezing. Lead acid is a real workhorse when it comes to the extremes.

            • @jabathekek@sopuli.xyz
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              82 months ago

              IIRC there is already an e-scooter you can buy that has a sodium ion battery. From a chinese company (ofc) that I forget the name of. It touts fast charging and basically performs just fin down to -20C.

              • SeekPie
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                2 months ago

                This one maybe?

                48 V and a capacity of 24 Ah

                400 W power and a 25 km/h top speed.

                They’re from $450 to $590, so amazingly priced.

                Fun fact: it would not be classified as a e-bike nor a moped in Estonia because it’s less than 1000w and max speed is no more than 25 km/h, but an mini-moped, which doesn’t need a license to drive, but you have to be older than 16 and need to wear at least a bicycle helmet.

          • @cmnybo@discuss.tchncs.de
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            52 months ago

            If you need to charge LiFePO4 batteries below freezing, you can add a heater to the pack. There are even some batteries available now with built in heaters that come on automatically below freezing.

          • @5in1k@lemm.ee
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            22 months ago

            Less than half in my experience. I bought two 100ah 12v lifepos and they are under 30 lbs. 23lbs I believe. I have a lead acid deep cycle of the same power and it’s like 80-90.

    • CrimeDadOP
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      11 month ago

      Thermal runaway probably shouldn’t be a realistic consequence of bad quality in any consumer product.