During the colder winter months you may find that the electric bike you purchased in the warm season of Fall doesn't quite operate the same that it did when you first got it. Don't worry. The problem isn't typically with the e-bike, the problem is with you and with chemistry and the natural laws of physics of your battery.
Each year, we find, the scenario runs like this: an energetic customer, fresh on the scene to biking and e-biking in general comes in and gets a new e-bike in the Fall, probably after an active summer of good weather and eager anticipation of lots of riding in their future. Then Winter starts to show itself. First in the way of Halloween and sugar and then the debauchery of Thanksgiving, company holiday dinners, Christmas feasts and New Year boozing. All the while, it gets colder and darker and wetter, gloomier.
Throw in a vacation or a long weekend and just weeks of staying indoors and plain old inactivity and two things tend to happen: you ride your bike less and your bike is ridden less. During this time, our bodies take on some winter weight and our lithium ion batteries too become inactive and lose effectiveness. You can see where this is going.
Come January or February, the weather starts to turn, it begins to warm up and New Year's resolutions are at play. We all want to take on the new year with more health and more activity and yet we've just been stuck indoors and inactive for the past 3 months. Eager to get back on our nearly new E-bikes, we set out after months of inactivity and we find, to our horror, that our trusty little e-bike isn't taking us as far as it did only a few months ago. It's not going as fast as it did and it's not climbing as many hills as it did. Something is wrong!
According to the Lithium Pros, "All batteries will perform poorly in cold weather, regardless of whether they are lithium or lead-acid." They say the "best way to maintain a lithium battery in this scenario is to charge it weekly". But as you can see, during the winter months, we often let this slide by sheer fact that we may not be around.
By the time the weather clears up, we haven't been charging our battery for a few weeks or even months and we also haven't been charging our own body's battery in a few weeks or months. When we get back on the bike we and the bike are not at the same power levels that we left them at in the Fall.
It stands to reason - and this applies both to the battery on the e-bike and the power of our bodies - that power levels will come back to what they were in the fall by activity and more frequent charging. Ie. to get more power and range back in your bike and you, use it more. Be more active and use your bike more. Charge your bike more often, preferably weekly at least, but after every ride ideally.
Keeping on riding will keep your body in shape and your battery too. Fortunately, unless you leave your Lithium battery uncharged for months on end, no major permanent damage will occur to your bike. That's a good thing. By starting to use and charge the battery more frequently, this normally "wakes up" the chemistry and brings it back to what you were used to.