Tech Updates

How to understand ebike and escooter battery specs

If you’re shopping for your first ebike or electric scooter, you might be a bit confused by the numbers you see on the spec sheet. What exactly is a watt-hour(Wh), and how is it different from an amp-hour(Ah)? Does voltage matter? How big of a battery do I really need?

With the help of some basic physics and arithmetic, we’re here to help you make sense of these numbers.

Which spec tells me the battery capacity?

When you look up an electric bike or scooter, chances are you’ll come across a variety of numbers related to the battery. These three are the most common ones: volts, amp-hours, and watt-hours.

Watt-hours (again, that’s ‘Wh’) are the most useful unit when it comes to energy capacity. If you’re looking to compare the battery sizes for two rides, you’ll want to look for the watt-hour rating on the spec sheet.

Assuming honest specifications, the bigger the watt-hour rating, the bigger the battery— longer the range.

I don’t see a watt-hour rating, only amp-hours and volts. Help!

While most ebike companies these days show battery ratings in watt-hours, many electric scooter companies still stick to volts and amp-hours. Worry not, my friend. Finding a battery’s watt-hour rating from volts and amp-hours is the simplest of multiplications. Here’s the formula for you:

Wh = Ah * V

That’s it. By the same token, you can find a battery’s amp-hour rating by diving the watt-hour rating by the voltage. Or divide the watt-hours by amp-hours to find the voltage.