Don’t Store a Completely Discharged Battery
Perhaps the quickest way to kill an e-bike battery is to completely discharge the battery then put the bike in storage. If the battery is completely discharged and left for an extended period of time it may become unrecoverable and may not take a charge. While a good battery management system should not allow the battery to become fully discharged, lithium-ion batteries self-discharge and lose their charge over time which could make the battery unrecoverable.
Don’t Leave the Battery on the Charger
On the other hand, don’t leave a battery on charge after it has reached a full charge. While most smart chargers will stop charging once a battery is fully charged, overcharging a lithium-ion battery can have disasters results. Once the battery is charged disconnect the charger. I set a timer to remind me to disconnect the charger when charging is complete so I don’t forget.
Don’t Store the Battery with a Full Charge
Similarly, don’t store a fully charged battery for long periods of time. Since I generally don’t ride my e-bike much in the winter. I discharge my battery to about 30-60% in the winter. It helps to improve battery life. If I do go for a ride, a 30-60% charge will generally give me enough juice to get me where I want to go and back.
Store the Battery in a Dry Place at Room Temperature
Finally, store the battery in a dry dry place away from direct sunlight at about room temperature. The battery should also be recharged at room temperature as well. When transporting an e-bike it is important to remove the battery from the bike and store it safely in the vehicle. On a recent bike tour along the Florida Keys, I left the battery on the bike on the carrier on the back of my vehicle in the hot sun and through a rain storm. I was luck that my battery made the trip without harm.