E-bike battery and the weather: how to deal with cold, heat and rain

A lithium-ion battery performs less well at low temperatures. The range gets shorter and the battery seems to run “flat” sooner. That does not mean the battery is broken. It does mean the chemistry in the cells is temporarily working less efficiently.

What you notice in the cold:

• Fewer kilometres on a full battery

• The capacity drops faster while you ride

• The battery takes longer to charge fully

Tips for cold weather:

• Keep the battery indoors at room temperature and only click it into the bike just before you leave.

• Need to charge the battery? Preferably do it indoors, not in an unheated shed.

• Is the battery ice cold? Let it warm up first before you charge it.

• Allow for a shorter range and plan your route accordingly.

That limits the effect of low temperatures on your battery and extends its service life.

Batteries have a harder time at high temperatures too. Heat speeds up the ageing of the cells and in extreme situations can cause overheating.

Avoid in summer:

• Leaving the bike in full sun for a long time with the battery on it.

• Leaving the battery behind in a hot car, camper van or caravan.

• Charging in a small, poorly ventilated space that is already very warm.

Dealing with heat sensibly:

• Park your e-bike in the shade as much as possible.

• Take the battery off if you are staying somewhere for a while and keep it indoors or in a cooler place.

• Does the battery feel very warm? Let it cool down first before you charge it.

That prevents unnecessary ageing of the battery and reduces the chance of problems.

Most e-bike systems are splashproof, but they are not made to stand in water for a long time or to get soaked through. Water and electronics remain a risky combination.

What to watch in wet weather:

• A shower while you are riding is usually no problem, but do not put a soaking wet bike straight into a warm room. Condensation can then form in the connectors and electronics.

• Let the bike drip dry first under a shelter before you bring it indoors.

• Do not blast the battery and connectors at high pressure with a pressure washer.

• After a period of heavy rain, check that there is no corrosion or deposit around the contact points.

Do you see rust, green deposits or moisture near the contact points? Then have the battery inspected.

How you store the battery when you are not riding has a big effect on its service life.

In winter:

• Store the battery indoors, dry and at room temperature.

• Do not leave the battery completely flat for weeks. Preferably store it at around 40 to 60% charge.

• Not riding for a while? Top the battery up a little every few months.

In summer:

• Do not store the battery in a space that stays very hot for long periods (a shed in full sun, for example).

• Avoid long-term storage in a car or caravan.

• The same applies here: preferably not completely full or completely flat for a long time.

Always watch for these signs in your battery, whatever the weather:

• The battery gets abnormally hot during use or charging.

• There is a smell, smoke or melt marks on or around the battery.

• The casing is deformed, swollen or cracked.

• The battery keeps cutting out or shows sudden big jumps in its charge level.

If you notice any of these signs, act straight away: stop using the battery, put it somewhere safe (preferably outdoors, on a non-flammable surface) and contact a specialist.

Do you think the weather has damaged your battery, or do you no longer trust the way it behaves? Then it is sensible to have the battery inspected.

At KWS Seuren we can:

• Measure and test batteries

• Assess whether a repair or cell replacement (all the cells are replaced with new ones) can still be done safely

• Safely take in and dispose of damaged batteries

Then you know where you stand and you are back on the road with a safe battery.

Want to be sure your battery is still safe to use after frost, heat or water damage? Get in touch with KWS Seuren. We will help you find a solution that fits, whether you ride privately, run a bike shop or manage a larger fleet of e-bikes.