eBike Batteries: An In-Depth Guide on Size & Range

One of the most common questions we get is “How far can this eBike go on a single charge?” and much to the chagrin of both the asker and myself, the most accurate answer is: It depends! Let's take a closer look at eBike mileage and the different factors that determine whether you can get to work and back, climb that mountain trail, or do a day's worth of food deliveries on your eBike.

First, let's examine the battery itself. We're talking of Lithium-Ion batteries only, as the days of Nickel-iron batteries seen on older ebikes are now obsolete. If you are familiar with the eBike market, you may notice that not much is standardized-not even battery units! Some companies like those with Bosch components usually list their battery capacity as Watt Hours or Wh, while companies like Samsung or Panasonic, often use Amp Hours or Ah. Watt Hours looks larger because it's a simple formula of Voltage x Amp Hours = Watt Hours. For example: Since (Ah)*(V) = (Wh) if you have a 13Ah battery rated at 48V, the power is 13Ah * 48V = 624Wh. The more powerful the motor, the more power it will draw.

Doing intensive activities like going uphill or riding on softer terrains, such as mud or sand, will drain the battery faster as the motor is pulling more power to maintain speed. This situation is more of an issue on hub-drive eBikes, as mid-drive eBikes are assisted by the motor using the mechanical advantage of the gearing. Some users may be encumbered by their weight or the weight of their cargo, meaning the motor will be working harder to build forward momentum. Thus, choosing an eBike with the correct size battery is extremely important and unique to each rider's needs.

Using your eBike's pedal assist and throttle also will drain the battery differently. Lower levels of pedal assist mean that your legs are doing the majority of the work and taking the strain off of the motor. We have clients who want an eBike they can use like a motorcycle-laying on the throttle with little pedaling. To that we say, more power to you! And, more power to the motor so be sure to have a large enough battery to compensate.

Some eBikes, like ones in the “Stealth” category, use a battery that must be small enough to fit inside the frame and are usually 9Ah or below. These are ample for light city riding, approx. 10-20 miles on flat ground or about 8-15 if hills are a major part of your commute. It's common to see eBikes with smaller 250 or 350 watt motors paired with sub 11Ah batteries, while more powerful 500, 750, and 1000 watt eBikes (such as our Goat Hill Explorer) can reach 17Ah+ capacities.

Batteries are often the most expensive component on an eBike simply due to the amount of raw materials that go into their construction. Lithium and cobalt prices fluctuate and are labor intensive to mine from the ground, so remember to maintain your battery correctly to avoid having to replace it early.