How to Determine E-Bike Battery Amp Hours – A Guide

Do you want to know the weather amp-hours have on an electric bike battery? This guide is all about how to determine e-bike battery amp hours!

Every electric bike uses a battery pack that powers its motor. Thus, the battery capacity has a significant impact on how much distance you can cover or how long you can depend on battery power when riding.

If you plan on using the motor a lot when you’re riding, you should invest in a bike that has a large battery capacity. This way, you’re less likely to end up relying solely on pedaling at some point on the road.

Therefore, if you want to get the most of your e-bike purchase, you must consider the battery installed on it. You can always buy a replacement electric bike battery pack, but that is an additional cost that you can skip for the first few years of use of your e-bike.

Now, various aspects of a battery affect how much mileage it will provide and how fast you can go. One of these factors is amp-hours (Ah), which measures your battery pack’s capacity.

Thus, this comprehensive guide will go over some of these factors and explain how to determine e-bike battery amp-hours. Once you know how to calculate the mileage, you don’t have to rely on the bike salesman’s word on the battery’s performance.

How to Determine E-Bike Battery Amp-Hours

Determining e-bike battery amp hours is necessary if you want to know how much distance you can cover on a single charge. The amp-hours rating should be present on the battery pack or the spec sheet of your electric bike battery.

Along with the amp-hours rating, the battery will most likely mention the voltage and watt-hours rating. With these figures, you can determine how much distance your bike can travel.

If you’re someone who enjoys biking a lot under the California sun, a significant battery capacity can be beneficial. Therefore, in order to correctly measure the mileage of electric bikes, you’re going to have to take a look at the voltage and wattage in addition to the amp hours.

Read: How to Remove Rust from Bikes

Understanding an Electric Bike Battery Amp-Hours

The amp hours on an electric bike battery is an energy measurement that indicates how much capacity the battery has. You can consider it similar to a vehicle’s fuel tank. Therefore, a battery with a more significant amp-hours rating will have more energy to supply to the motor than a battery with a lower amp-hours rating.

However, a high Ah rating does not automatically mean that you can travel more distance with it. Like in a vehicle with a fuel tank, the amount of distance you can cover depends on how much energy the motor draws from the electric bike battery. Therefore, voltage is an important factor to consider.

Before we begin discussing voltage, it’s best to understand Ah ratings in greater detail. An electric bike battery with a 14 amp-hour capacity should ideally supply a current of 14 amps continuously to a source for precisely 1 hour until it discharges completely.

It can also supply 28 amps for half an hour, or 7 amps for 2 hours, and so on. These figures are in ideal circumstances, and some energy is lost in heat as well.

Moreover, the amount of distance you can get from your electric bike’s 14-amp battery also depends on the weight of the bike, the rider, how much pedaling effort you put in, and so on.

Determine E-Bike Battery Amp Hours
A woman riding an e-bike

Understanding Voltage on Your E-Bike Battery

An easy way to understand voltage on your e-bike battery is to consider it as the electromotive force that drives the amps through the battery. Higher voltage can move more energy or push it at a faster rate.

An e-bike battery with a high voltage rating will send more energy to the bike’s motor, making the motor more powerful. However, each motor and controller have specific voltage compatibility.

So, you cannot use any battery on your electric bike. Installing a battery pack with a higher voltage rating than what the motor and controller supports may damage the controller. Supplying additional voltage is known as overvolting. It can be useful for improving performance, but there’s undoubtedly a risk.

Most electric bikes have 36V batteries. This voltage rating offers good mileage and enough power to the motor to keep the ride comfortable.

Some electric bikes also have 48V or 52V batteries, especially on high-performance machines. These batteries will help make your bike pick speed up faster, but it drains the battery quicker.

Read: How To Clean a Mountain Bike

Determining Electric Bike Battery Amp-Hours through Watt-Hours

While your electric bike battery will most likely mention the amp-hours, you can still calculate it yourself if it’s not present. You will need the watt-hours (WH) and the voltage ratings for this calculation. WH is also a measurement for battery capacity.

However, it takes into account the voltage rating of the battery as well. You can calculate WH for a battery by multiplying the amp-hours with the voltage rating.

Therefore, you will have this formula: WH = Ah x V

If you don’t have the Ah value for your battery, you can change the formula to this: Ah= WH / V

For example, if your e-bike’s battery has a 36V rating and 360WH rating, you can determine the amp-hours by dividing the WH value with the voltage value, giving you 10 amp-hours (360 / 36 = 10).

If you plan on purchasing a new e-bike, you should take the watt-hours into account as well. This rating determines the range your bike can travel, your bike’s cost, and your bike’s weight. All three of these factors are critical to consider when you want to purchase an electric bike.

Determining How Much Distance You Can Travel

Now that you have a good understanding of amp-hours, voltage, and watt-hours, you can determine how much distance you can travel with your e-bike’s battery pack.

As mentioned earlier, you cannot calculate the exact distance because it greatly depends on how much power you use from the motor per mile.

If you rely heavily on your pedaling, you will consume less energy from the battery, and it will provide you with better mileage.

On average, you can expect to spend anywhere between 10WH to 20WH every mile. With that in mind, you can calculate how much distance the e-bike can cover on a single charge.

Using the example above of a 360WH battery, you can travel around 36 miles to 18 miles, depending on how much you use the motor.

Traveling 36 miles is optimistic, as you’ll most likely be traveling around the 18-mile range if you prefer a comfortable ride. The actual numbers come down to how you use it and the bike itself.

Here are some examples of common and possible electric bike battery packs’ configuration and the range they would provide.

  • 36V, 9Ah, 324WH = 16.2 to 32.4 Miles
  • 36V, 12Ah, 432WH = 21.6 to 43.2 Miles
  • 48V, 10Ah, 480 WH = 24 to 48 Miles
  • 48V, 17.5Ah, 840 WH = 42 to 84 Miles
  • 48V, 20Ah, 960 WH = 48 to 96 Miles

Also read, How to Ride an Electric Mountain Bike

Other Factors that Affect Electric Bike Battery Life

All of the e-bike range examples are just a reference to what you can expect from your bike. However, there are additional to consider.

You must understand that conserving battery charge when riding does affect your e-bike’s range. Therefore, here are some other factors that affect electric bike battery life.

The Bike’s Pedal-Assist System Can Affect the Range

While it does matter how relaxed you keep your pedaling for improving the range, some pedal-assist systems (PAS) are more prone to taking up battery power than others. The PAS affects how much power the controllers supply to electric bikes’ motors.

A bike with pedal assist incorporates a combination of battery power and pedaling force. Thus, you have significant control over how much battery is drained from your usage.

On the other hand, some electric bikes come with a throttle system. In that case, you can rely entirely on the e-bike’s motor, which can be handy during long rides in Florida.

The downside of this system is that you will use more battery power because you won’t support the motor with pedaling power.

Therefore, you will end up decreasing the range of your e-bike significantly. You may see that you won’t get much range even with a high amp-hours value unless you pedal for a significant portion of your ride.

The Sensor Can Affect the Range

If you want to purchase an electric bike with a good range, you should check what sensor is present on it. The good news is that most PAS bikes in the USA and other countries in North America use torque sensors on e-bikes instead of cadence sensors.

Torque sensors are a much better option because they provide less power to the motor if you pedal lightly and vice versa. Thus, this type of sensor helps increase your electric bike’s range. This way, you won’t have to worry about running out of battery power midway through your ride when traveling long distances.

Cadence sensors, on the other hand, are like a switch. They only enable and disable the PAS system, which means you do not have much control over the range through pedaling force.

How to Increase an E-Bike’s Range

Understanding your e-bike battery’s amp-hours, watt-hours, and voltage is just one part of getting the most of your electric bike. Even with figures that are not the best, you can still get a good range from your e-bike on a single charge. Take a look at some of these tips on how to increase an e-bike’s range.

Reduce the Assistance Level

The PAS system on your electric bike will most likely have an assistance adjustment. You can increase it for a more effortless ride or decrease it to save battery power and better exercise. The lower the assistance level, the more battery you conserve, which, in turn, increases the range.

Switch Your E-Bike’s Gears Properly

Your electric bike’s gears are designed to make the overall ride as smooth as possible. Much like and an automobile, e-bikes have specific gears for certain speed ranges. Thus, you must keep shifting the gears as you change the pace.

Using the correct gears at the right speed will create less resistance to the pedals, making it less necessary to keep your pedal assistance at a high setting. As a result, you can turn down the assistance level and preserve more of your electric bike battery.

You should also note that using high gear will help you reach greater speeds, but it will drain the battery faster.

Cycle at a Slow Pace as Frequently as Possible

Cycling faster and applying more force to the pedals makes the torque sensor send more power to the motor. Due to that, you will deplete the battery power more rapidly, which will decrease the overall range.

It’s best to stick to a comfortable pace when riding if you are not in a rush. You won’t ire yourself in reaching your destination, and you also will lower the chances of running out of battery power on the way there.

how to determine e-bike battery amp hours
Batteries on electric bikes

Charge Your E-Bike Battery After Using It

It’s best not to wait for your electric bike battery to drain completely before charging it. Instead, charge it every time after you use your electric bike. This way, you’ll have a fully-charged battery whenever you start your ride, providing you with the bike’s full range.

In addition to that, you should also consider charging your e-bike’s battery when it’s at 50% capacity. Typically, charging lithium-ion batteries at that percentage can help prolong their lifespans.

Thus, you can ensure that your range stays more or less consistent after several months of use. Lithium-ion batteries don’t last very long, so it’s best to try and keep them in good condition for as long as possible.

Keep Correct Air Pressure in Your Tires

An electric bike’s tires create more drag if the air pressure in them is inadequate. As a result, the e-bike’s motor will have to be work harder to keep it running at the desired speed. Therefore, it will begin to drain the battery faster and decrease the range in the process.

Look at the side of your bike’s tires to determine the correct air pressure. It’s best to check the air pressure every other day before you start riding your e-bike.

Reduce Extra Weight from Your Bike

A heavier e-bike will require more power from the battery. This is because a heavy e-bike requires more force to start moving and maintain a consistent speed.

If you’re used to carrying a lot of things in the basket, try and reduce some of them that are not needed. Even a bit of a weight change can increase the range on your e-bike.

Swap Your Tires for Thinner Ones

You can reduce the drag your e-bike tires create by swapping your existing ones for thinner tires. As a result, you can reach faster speeds with greater ease and reduce the load on your motor. Thicker tires are better suited for off-road terrain because they provide better traction and balance on sun surfaces.

Thin tires are best for roads with minimal drag, which is why racing bikes have thin tires as well. If you don’t plan on riding your e-bike on off-road terrain, thin tires are your best option.

Along with thin tires, you can consider tires without knurling on them. The knurling is only needed for providing additional traction on off-road terrain. Thus, smooth tires will provide less drag on the road without affecting your grip.

Make Sure the Brakes Don’t Rub Against the Tire

If you’ve been riding your e-bike for some time, there’s a chance that the brakes may become a bit loose. As a result, they might rub against the tire when you’re pedaling your electric bike.

Electric bikes with this issue suffer from a reduced range because of the additional friction because of the brakes engaging with the tire. You will have to pedal with greater force because of this, which will provide more power to the motor.

Therefore, you must check your brakes regularly to ensure your bike doesn’t suffer from this problem.

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Last Words on How to Determine E-Bike Battery Amp-Hours

While it’s essential to know how to determine e-bike battery amp-hours when purchasing an electric bike or a new battery for one, you must not get caught up in its specs only. Specifications are good for giving you a good guideline on how your bike and its battery will perform, but it does not provide the full picture.

What you can get out of your electric bike battery depends significantly on how you ride it and how much care you take of it over time. If you’re someone who enjoys riding your e-bike for long distances in a day just try and travel slowly and with less assistance. That way, you will have battery power left until you reach your destination. Happy biking!