The battery is the heart of an e-bike: a lithium-ion pack that powers the motor assisting your pedalling. Depending on the manufacturer it sits in the frame, on the down tube or on the rack, but it is always removable and has an LED charge indicator. The casing is built to cope with rain and mud, yet two things still shorten its life: cold and moisture on the contacts.
A few simple habits help the battery hold its capacity longer and deliver current reliably. This matters all the more in a climate with hard frosts, thaws and sudden temperature swings.
What you will need
Important: Never open the battery casing, and do not charge a battery that is swollen, cracked, overheating or smells burnt. Take it to the manufacturer's service instead.
Step 1
Keep the battery away from the cold
Any lithium battery loses a lot of capacity in frost. Do not leave the bike with its battery outdoors or on a balcony when the temperature drops several degrees below zero, and avoid riding in severe cold where possible.
If the bike sits unused in winter, remove the battery and keep it indoors somewhere dry, no colder than +15 °C. When carrying the bike on an external car rack, take the battery off and put it inside the car.
Step 2
Protect it from moisture
Condensation after a summer downpour or a sudden cold snap oxidises the contacts. Oxide restricts the flow of current, so the system works less efficiently. Overly vigorous washing has the same effect, especially with a pressure washer, which is best avoided altogether.
Always remove the battery before washing the bike and before lubricating mechanical parts.
Step 3
Clean the contacts
With the battery out, inspect its terminals and the contacts in the frame cradle. Any green or white deposits, darkening or dirt should be removed. Apply WD-40 Specialist Contact Cleaner to the contacts, leave it a few seconds and wipe away the loosened dirt with a dry cloth. It dissolves grease, dirt and condensation, evaporates quickly and leaves no residue.
Refit the battery only when the contacts are completely dry.
Step 4
Charge it correctly
Use the original charger. Charge the battery at room temperature, and after it has been out in the cold let it warm up for at least an hour first. Do not leave it fully discharged for long, and do not keep it on charge around the clock.
Step 5
Store it properly off season
Before long storage, charge the battery to roughly half rather than leaving it empty or full, unless the manufacturer advises otherwise. Every month or two, check the indicator and top it up to a medium level if needed.
Tip: Before your first spring ride, go over the contacts with
Contact Cleaner once more: winter condensation often leaves a light film of oxide.
What next
Check the contacts monthly during the season and after every ride in the rain. Mechanical parts near the battery cradle, such as bolts and the mounting lock, can be protected from rust after washing with a drop of WD-40 Multi-Use, keeping it away from the contacts themselves.
These uses come from the experience of WD-40 users in many countries. Always follow the instructions and warnings on the product label.
More guides in «How to use».