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.
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.