Electric Bikes: The Battery

Here are some types of electric bike batteries and their characteristics:
Lithium (Li) batteries:
- Lighter and more efficient
- Require less maintenance and last longer
- Most commonly used in modern e-bikes

Nickel-Metal Hydride (NIMH) batteries:
- More expensive than lithium batteries
- Used for their double range capacity compared to lead-acid batteries

Lead-Acid batteries:
- Cheaper and heavier
- Take longer to recharge
- Used more in older e-bikes

Lithium-Ion batteries:
- Most e-bikes use this type of battery
- Better performance and range

Lithium-Polymer batteries:
- Used in e-bikes with higher voltage needs
- More expensive than other lithium batteries

Other things to consider about e-bike batteries include :
- Volts (V): Measures how fast electrons move in the battery
- Amps (A): Measures the capacity to deliver electricity
- Watt-hours (Wh): The combination of volts and amps, measures the capacity of the battery
- Amp Hours (Ah): Measures how long a battery can sustain a fixed number of amps

When it comes to range estimates, how far an e-bike can go on a single charge, here are some facts to keep in mind:
- Expect 20 miles (32 kilometers) of range from an average 6 to 8-pound Lithium battery
- Range varies greatly depending on battery weight, terrain, and level of assist
- Vendors often overpromise on range estimates to make a sale
- Some e-bikes have pedal sensors and no throttle at the handlebars, which require pedaling for power to flow and have different range estimates .

Amps and Volts combine to Watts, with higher Volts providing more speed and higher Amps requiring thicker wires and/or more powerful and larger battery packs. Most e-bikes do not use power at an exact level, continuously, so this does not directly translate into ride time. However, a larger battery with more energy (capacity) can deliver lower power levels for longer periods of time, and go further on a charge.

Here is how the battery capacity translates into distances:
- A 6-8lbs Lithium battery has a range of 20mi (32km)
- A 36v 10ah battery pack with 360 wh of capacity will provide 36 km of range, or 22 miles, from a full 100% charge
- A lead acid battery that can run for an hour of riding under worst case situations is usually sized properly
- A larger capacity battery will not have to work as hard as a smaller battery when used on a given bike
- A 10ah battery delivering 500w continuous will run for half the time of a 20ah battery pack

Keep in mind that your actual mileage will vary depending on several factors, including voltage, capacity, and the actual weight of the battery.