Reliable and efficient battery charging is crucial for riders and the places they go. Unlike their fully manual relatives, e-bikes come with a clear dependency (hint, it’s in the name): electricity. And they need it often, with most riders charging their batteries 3-4 times per week. Yet given how vital electricity is to enabling e-bike ownership, when was the last time you considered the math behind how the ‘e’ actually makes it to the ‘bike’?
One of the most common questions we encounter is about the power requirements for charging multiple e-bike batteries simultaneously. In this post, we’ll break down the math behind power draw and explain how many chargers you can power at one time. We’ll be using European examples here, but the principles remain the same for international readers.
Where does electricity actually come from?
Power has its own journey to take for it to make it to your battery. First it has to be created. In the European Union, electricity is generated from a mix of sources: approximately 40% comes from renewable energy, including wind, solar, and hydroelectric power. Nuclear energy contributes over 20%, while fossil fuels – primarily natural gas and coal – account for around 39% of the electricity mix. Once generated, it’s then transferred via the electrical grid to a central electrical service panel in your building, then to each outlet.
The Basics of E-Bike Charging Power Needs
When riders make it where they’re going and have a low battery, it’s second nature to plug it in to charge. Yet nearly all of us take for granted how this actually works. Too much demand on a buildings power can lead to tripped circuit breakers or in very rare cases, damage to the buildings electrical. We’ve designed our lockers so you’re not at risk of this. Still, we still think it’s interesting to explain the math behind charging at scale.
To understand how many e-bike chargers you can operate at once, first you need to understand the power capacity of your electrical outlet and the power requirements of the chargers. You can think of your wall socket as a pipe, and the electricity as water running through it. Here
Meet the standard European outlet (Schuko):
Voltage: 230V
Voltage is how strong the push is to move electricity.
Current: 16A
Current is how much electricity is flowing.
Power: P = V × I = 230V × 16A = 3680W
Power is then the total amount of electricity available to use as a result of how much and how quickly it moving.
This calculation shows that a standard European outlet can deliver up to 3680 watts of power.
So, how many e-bike batteries can you charge at once?
So if you have 3,680 watts available via a given wall socket, how many batteries could you theoretically charge at once?
We’ll use the Cowboy Standard Battery Charger as an example. The charger has an input power of 140 watts. To find out how many e-bike batteries can be charged simultaneously, follow these steps:
Determine the total available power from the outlet:
Total Power: 3680W
Determine the power required for each e-bike charger:
Power per charger: 140W
Calculate the number of chargers:
Number of chargers = Total Power / Power per charger
Number of chargers = 3680W / 140W = 26.29
This calculation indicates that a standard European outlet can support 26 chargers operating simultaneously. It’s important to note that there are some much larger chargers on the market, such as the Bosch 6A Fast Charger (500 watt), which are much more demanding.
Practical Implications
Understanding these power requirements are an important step to designing effective e-bike battery charging solutions. While a single outlet could support 26 batteries charging on multiple power strips, that’s a really bad idea in practice.
Here are some practical tips we suggest you keep in mind when supporting any kind of battery charging at your location:
Assess Circuit Capacity: Ensure that the electrical circuits at your location can handle the total power draw from multiple chargers and anything else that draws power. Consider installing dedicated circuits if necessary to avoid overloading.
Optimize Charging Times: Take advantage of lower energy prices by charging during off-peak hours, typically late at night or early in the morning. This not only reduces electricity costs but also helps ease the demand on the grid during peak times.
Avoid Daisy-Chaining Power Strips: Never connect multiple power strips together and plug them into a single outlet. This practice, known as daisy-chaining, can easily overload the circuit, leading to electrical hazards such as overheating, tripped breakers, or even fires.
4. Educate Riders: Set clear expectations for riders on where they can charge their batteries, how to avoid overcharging, and when to report any issues. This helps maintain safety and efficiency.