E-bike giants Pedego have released a little guide to keeping your battery in top condition. Here are their three tips:
Environmental conditions are an important factor affecting lithium batteries. For example, leaving one in your car in the hot sun will guarantee you lessen the life of your battery. In fact, that would be the worst situation: keeping a fully charged battery at elevated temperatures. It’s a good rule of thumb to store your bike out of the direct sunlight for long periods and when not in use, keep your battery in a cool place, preferably below 20°C (68°F). The chart below, provided by Battery University, shows the impacts of temperature upon recoverable capacity of a battery.
You’ll also notice in the above chart that storing a fully-charged battery has an impact on the recoverable capacity. Even more important, storing a fully depleted battery may be disastrous because, as we mentioned above, a lithium-ion battery will slowly discharge over time even when you’re not using it. If the voltage drops below a certain point this may cause irreparable cell damage, depending on the time it’s left sitting. Ideally, when storing the battery for a long period ensure it has less than 100% charge (5 bars, if you have an indicator on your battery) but more than 40% (2 bars). Some chargers have a lower ‘storage’ voltage setting, so just switch to this before charging it for storage. An easy alternative is to take the bike for a short ride after you’ve charged it fully and before storing.
If you’re forced to store the battery for prolonged periods of time, make sure to check your battery every couple of months. If you notice that the battery indicator has dropped to one or two lights (out of five) give it a bit of a charge. If you don’t have a battery indicator, it’s probably a good idea to charge the battery for a half hour or so every few months. Again, try not to put the battery away fully charged (but it won’t be the end of the world if this happens.)
It’s amazing that we still see tech sites advising regular full discharge of your battery, even when this has been proven as detrimental. The chart below, again provided by Battery University, proves that regularly discharging lithium-ion batteries to 0% is harmful and partial discharges with regular top-ups are recommended to extend the recharge-cycle lifespan of the batteries. The occasional full discharge on that extra long ride is no problem! If you are doing very short rides on a regular basis, it is slightly better to charge it every few rides rather than every ride.
Correct maintenance and storage of your battery as detailed above will significantly increase its lifespan. A well-maintained lithium battery will last between three to five years, whereas a poorly maintained battery can be badly damaged over just one season or sooner. For more detailed, scientific information on batteries and how to care for them, check out the excellent online resource at Battery University, where the above charts came from.