So, it’s well-known that lithium batteries lose capacity when temperatures drop well below freezing. However, since they generate some heat while discharging too, it seems logical that insulating the battery to retain this heat could help extend range in cold weather. My question is whether this makes a noticeable difference in real-world use?

I’ve been browsing eBay, but most covers seem to fall into two categories: uninsulated rain covers for external batteries or neoprene sleeves for built-in ones. My fatbike has an external battery, so I quickly jerryrigged a cover using a 20mm Armaflex sheet I had lying around. While it obviously didn’t hurt, I can’t say I noticed much improvement either.

Does anyone have long-term experience with insulating battery covers? I’d also appreciate recommendations for a good cover for external battery or tips on how to DIY one.

  • Brkdncr@lemmy.worldEnglish
    4·
    2 months ago

    I wonder if adding heat strips to keep it warm like an engine heater while charging would be of any help.

    • Free_Opinions@feddit.ukOPEnglish
      2·
      2 months ago

      I have those reusable hand warmers that you can reactivate by boiling in the water. If ones like that but larger existed then maybe putting few under the insulation on my way back home would be able to squeeze those few extra kilometers out of it.

      • _haha_oh_wow_@sh.itjust.worksMEnglish
        6·
        2 months ago

        Anything that keeps it from freezing would help, just be careful not to let it overheat too. They also sell battery powered heating vests/blankets that could be repurposed into a makeshift heater. Zippo also sells fuel powered heaters (as well as battery powered hand heaters).

        • litchralee@sh.itjust.worksEnglish
          1·
          2 months ago

          just be careful not to let it overheat too

          My other comment explores how much insulation might be needed to make a battery pack too warm. And it’s a difficult pickle, since insulating a pack well tends to imply that the insulation won’t be removed later. And yet, the narrow temperature range of li-ion means either the insulation must be shed to keep the pack happy or – bizarrely – some active cooling is needed to keep an insulated pack from getting too warm.

      • Telorand@reddthat.comEnglish
        1·
        2 months ago

        Keeping the “don’t overheat it” advice in mind, I wonder if you could rig up some sort of Peltier heater or resistive heater that is connected to your pedals.