riding an e bike up constitution hill swansea

Electric Bikes - Charging E Bike Batteries

The power source of electric bikes

The battery provides all the electrical energy for an e bike. Lithium ion battery packs are the most up to date technology and all our e bikes are fitted with them. Here is all the information you need to charge and care for an electric bike battery pack.

How long do e bike batteries take to charge?

The time that it takes to charge an e bike battery depends on the battery capacity. Charging a battery isn’t like filling up the petrol tank of a car as the first part of the charge is quicker than the final part. This means that you can charge a battery to half capacity in about a third of the time that it takes to be fully charged. An 80% charge takes about two thirds of the full charge time.

Battery capacity

Half charge*

Full Charge*


1 hour

 2 ½ hours


1 ½ hours

3 ½ hours


2 hours

4 ½ hours



* Based on Bosch PowerPack with standard charger.

The type of charger also makes a difference. The fast chargers supplied with some high-end e bikes will charge the battery 25% quicker than a standard charger. Some entry level e bikes come with compact chargers. These may take up to twice as long to fully charge the battery pack.

e bike with bosch active plus motor riding up hill

Can I take the battery off the bike to charge it?

With most e bike batteries, you can choose to charge them either on or off the bike. Batteries that sit on the top tube or rack of the bike are easily removed for charging. Some of these batteries can only be charged off-the-bike while others give you the choice of either on or off-the-bike charging.

Battery packs that are integrated into the downtube of an e bike can all be charged on-the-bike as well as off-the-bike. Some fully integrated battery packs are a little inconvenient for daily removal, so on-the-bike charging is best. That said all these battery packs can be removed without the need for specialist tools, so off-the-bike storage and charging is always an option.

Are e bike batteries affected by cold weather?

While you can ride an e bike in all the same weather conditions as a regular bike there are a couple of precautions that you need to take while storing and charging the batteries. Freezing temperature conditions aren’t good for lithium ion batteries, so it is best to store the battery indoors throughout the winter months. Riding an e bike at low temperatures is fine as the battery heats itself up while in use.

e bike with bosch active plus motor riding up hill

e bike with bosch active plus motor riding up hill

Do I need to take any precautions when storing and charging e bike batteries?

If you plan to store your e bike in a garage or shed then it is best to choose one with an easily removable battery, so you can charge and store it indoors during the winter and on hot summer days. If you intend to store your e bike in your home, then you don’t need to worry about whether the battery is easily removable or not.

For the longest battery service life, store and charge your battery in a dry environment, at room temperature and protected from direct sunlight. For long term storage ensure that there is at least 50% charge in the battery pack before storing. When transporting an e bike, it is best to take off the battery and store it in the car.