How to calculate how much costs to charge an e-bike battery? Guide

How much does it cost to charge an e-bike?

How much it costs to charge an e-bike depends primarily on two factors: the capacity of the battery and the price of electricity. The price is also indirectly affected by the efficiency of the charger, but most of these devices have an efficiency of around 90%, so even for an accurate calculation we can assume this parameter value. Standard bicycle batteries have a capacity of 300 Wh to 700 Wh.

How to calculate the cost of charging a battery?

To calculate the cost of charging your battery, use the formula below:

Charging cost = (battery capacity Wh) / charger efficiency %) x (price of electricity per kWh) / 1000)

Formula 1. Formula for calculating the cost of charging an electric battery

As you can see, for an accurate calculation according to this formula, you need the battery capacity expressed in watt-hours (Wh). Meanwhile, the most common way to describe an e-bike battery is by its rated voltage (V) and capacity expressed in ampere hours (Ah). To calculate the capacity of your battery in watt-hours from this data, use the following formula:

Battery capacity (Wh) = rated voltage (V) x capacity in ampere hours (Ah)

Formula 2. Formula for converting battery voltage and amperage into watt-hours

Calculation examples:

• Example 1. A 36 V 15A E-Bike battery has a capacity of 540 Wh (36 x 15 = 540 Wh).
• Example 2. A high-performance battery for an e-bike with 48 V 19.2 Ah has a capacity of 922 Wh.

How much does it cost to ride 100 km on an electric bicycle?

Even simpler, you can calculate how much it costs to ride 100 km on an electric bicycle. It depends on the price of electricity and the electricity consumption of the e-bike over the indicated distance, which is influenced by:

• the dynamics of the ride,
• the selected mode of assistance,
• the weight of the cyclist and the vehicle,
• weather conditions,
• and even tyre pressure and condition of bearings in wheel hubs.

Therefore, the electricity consumption of an e-bike varies between 0.5 and 1 kWh. For the purposes of our calculations, we can take an average value, i.e. 0.75 kWh / 100 km and use the following formula:

Cost of driving 100 km on an electric bicycle = Energy consumption (kWh) x Price of electricity per 1 kWh

Formula 3: Formula for calculating the cost of driving 100 km on an electric bicycle

Does an electric bicycle consume a lot of electricity?

No, an electric bicycle does not consume much electricity compared to other electrical appliances. A typical fridge, for example, on average consumes around 1 – 2 kWh per day, an amount of energy on which an e-bike can cover even more than 250 km.

An electric kettle with a power output of 2,000 watts will consume around 100 Wh in the three minutes it takes to boil water. This means that five boils per day consume almost as much energy as one charge of a 36V 15A bicycle battery.

The bicycle compares even more favourably with the e-car. Most of these vehicles require around 15 – 20 kWh to cover 100 km, which is the amount of energy that an e-bike would use to cover between 2,000 and over 2,600 km.