Almost every e-bike sold in Australia today uses a lithium-ion battery, the same underlying chemistry as a laptop or phone battery, just much larger. Lithium-ion cells degrade with every charge cycle regardless of how well they are treated, but how they are charged and stored has a real effect on how many years they last before that degradation becomes noticeable.
Charging habits
- Full charges to 100 percent are fine occasionally, but leaving a battery sitting at 100 percent for long periods accelerates degradation
- Letting the battery run flat to 0 percent regularly is also harder on the cells than keeping it in a moderate range
- Always use the charger that came with the bike, or a direct manufacturer replacement, mismatched voltage or current can damage the cells
- Charge in a moderate temperature room where possible, avoid charging a battery that is still hot from riding or one that is very cold
Storage
For storage longer than a few weeks, such as over winter, most manufacturers recommend charging the battery to roughly 40 to 60 percent rather than storing it full or empty, then checking it every month or two and topping up if it has drained low. Store it indoors at room temperature rather than in a hot shed or a cold garage, both temperature extremes accelerate degradation while sitting unused.
Heat is the main enemy
Lithium-ion batteries degrade faster in heat than in cold. Never leave an e-bike battery in direct sun, in a hot car, or against a wall in full afternoon sun in summer. Cold affects performance temporarily (reduced range on a cold ride) but heat causes lasting damage to the cells.
Warning signs to act on
- Swelling or a battery case that no longer sits flush
- A noticeable drop in range over a short period, well beyond normal gradual degradation
- Unusual heat during charging, or a charger that will not complete a charge cycle
- Any damage to the casing from a drop or impact