What Size Battery is Best for Electric Bikes? An Ultimate Battery Size Guide!

Batteries are the soul of electric bikes. Therefore, we need to check the compatibility and the right size. We cannot choose any random batteries, as it affects the performance of the electric bike a lot!

So, our main goal is to find out what size battery is best for electric bikes of various wattages. Here size means, battery voltage, Amp-hours & Watt-hours. Don’t be confused!

Here, in this blog, we will cover the importance of the correct size batteries for electric bikes, how to calculate the right battery voltage & Amp-hours for an ebike, and what sizes are best for ebikes with several wattages (500w, 750w, and 1000w, etc.)

So, stick to the end to clear all your doubts and choose the perfect battery for your bike.

Let’s dive right into it.

Electric Bike Battery: An Overview

Electric Bike Battery Sizing Guide

We understood the importance of batteries because they are the fuel on which electric bikes run. But why is it so important to choose the right battery size for your bike?

Why does the battery size matter so much? To understand this let’s get to the basics a little bit.

The very first thing for you to understand is the greater the size (Watt-hours) of the battery, the greater the speed will be and the smoother your experience will be.

You would not need to worry about the charge (battery level) and go about your journey without being interrupted. But good things come at some cost, isn’t it?

But, the negative part of this is, the greater the battery size, the heavier your bike will become. But in some cases, it becomes very essential to have higher-size batteries like in the case of electric MTBs & Electric hunting bikes.

And also, this does not mean you can plug in whatever battery in whatever bike. There is a specific way to go about that!

Don’t worry! we will be delving into all that part, but for now, let’s look at what is the importance of the correct battery size for your bike.

Importance of Correct Battery Size for Your Ebike

Well, it’s already been mentioned that the correct battery size for your bike is important. But why is it, here are 5 reasons for it:

1. To avoid insufficient power

When a battery is too small for an e-bike it can result in insufficient power output. In this case, the electric motor is not able to receive enough energy to provide adequate assistance.

This results in several factors such as slower acceleration, reduced top speed, and lack of power when you are riding uphill or in the opposite wind direction. All this will in turn impact the overall experience of bike riding.

2. To avoid a limited range

For traveling a satisfactory range from your ebike, you must have a large capacity battery because smaller batteries will fail to give a good distance to travel.

You can find yourself running out of battery very quickly and it will require you to recharge the battery all the time hampering the riding experience.

This can be very problematic when you are looking to travel long distances as it will hinder the ability for you to reach your destination comfortably without thinking of recharging the battery again and again.

3. To avoid weight imbalance

Choosing a battery that is too big for your bike can lead to weight imbalance which is not at all a good thing. This affects the overall weight resulting in imbalance and affecting stability.

A poorly balanced bike will feel awkward to ride, making it even more challenging to control safety. It will also be very uncomfortable and may lead to the fatigue of the rider.

4. To avoid compatibility issues

A very significant factor is the compatibility issue. When you choose a battery that does not fit the bike properly, it will lead to compatibility issues. It will not be able to fit the compartment made for the battery, it will not be securely attached which can lead to damage during rides.

This in turn will affect the riding experience because the power will run out easily and the connection won’t be very reliable. Also, ill-fitted batteries destroy the aesthetics of a bike, diminishing the overall design.

5. To avoid premature battery wear

When you use a battery that is too small for your e-bike, it results in excessive strain on the battery cells because of the high power demand by the ebike motor.

This leads to depletion of the battery’s capacity and reduces the overall life span of it. Premature battery wear would mean that you will have to replace the battery very often, which would result in you paying for it several times, increasing your expenses.

Here you do, these were the 5 very important points that explain why getting the right-sized battery for your e-bike is important. But how do we know what is the right size for an ebike battery?

Well, there are a few ways by which you can do it. Read the next paragraph, and you will understand.

How to Calculate the Correct Battery Size for an Ebike?

We saw that using the correct voltage battery with the right AH is important and now we are ready to know what is the best size battery for an electric bike and how to calculate it!

Several factors come into play for calculating the right battery size for the e-bike! Here you go:

1. Determine your riding needs

Understand the requirements of your traveling on the e-bike before going to calculate the right size. How much do you travel, how long do you travel, what is the kind of terrain you cover?

Ask these types of questions. It will give you some idea of what battery power you might need on your ebike according to its motor wattage.

2. Understand the voltage and capacity of a battery

These are the typical terms a battery is marked with. V is for voltage and Ah is for Amp-hours (capacity). Voltage in the battery represents the force and capacity represents how much energy the battery can store.

By multiplying both of these you can determine the Wh (watt-hour) of the battery, which represents the total energy storage of the battery.

Watt-hour = Voltage (V) x Amp-hours (capacity)

3. Power (voltage) demand of your ebike motor

Next, you have to estimate the kind of power consumption your e-bike has. How is it determined? By your pedaling effort, motor power, and riding conditions.

You will find the required voltage on the ebike motor if not, you can consult the manufacturer for a better understanding.

4. Battery size, space & weight

Take into consideration the battery space your e-bike has, the weight limitations, and your budget. Find a balance between the desired capacity and the practical limitations of your bike.

5. Mathematical calculation of ebike battery voltage & AH

Now, you are ready to calculate the correct battery size for your bike and how do you do that?

To calculate the right battery size you need to multiply the volts and the ampere-hour to get the WH (wattage per hour). If the wattage per hour is close to the power of your ebike, the battery is the right size for your bike.

For example, the battery’s voltage is 52v and capacity is 40Ah, multiplying both you get 2040Wh which means this battery is the right fit for a 52v 2000W electric bike.

Wattage per hour (WH) = Volts  x  Ampere-hour

WH = 52v x 40Ah

WH = 2040wh

So, You would need need 52v 2000W ebike battery!

There you go, now you know how to calculate the correct size of battery for your electric bike.

What Size Battery is Best for Electric Bikes?

Having covered all the factors and importance for calculating the accurate battery size for the electric bike, we will look at some battery sizes specific for some sets of bikes! Are you ready?

what size battery for an electric bike
Image showing what size battery should you get on an e-bike

What size battery for a 250w electric bike?

For a 250W ebike, a battery with a capacity 10Ah to 14 Ah is suitable. Any battery under this capacity provides a longer range on 250w ebikes, allowing the rider to ride for a longer time without having the concern of recharging it!

Because a 250w electric bike is an entry-level bike mostly used for commuting on paved roads. That’s why they don’t need a high-powered battery.

The distance that 10Ah can cover is 25 to 40 miles and a 14Ah can go further from 35 to 55 miles. But remember these ranges may vary on various factors such as rider’s weight, terrain, riding style, and so on.

Basically, choosing a 36v battery with a 10 to 14 Ah capacity for your 250w electric bike will be good. It will give you a decent range and top speed of around 20mph but make sure you are keeping in mind the terrain and your weight factors in mind.

Do you still have doubts? read this comprehensive ebike battery sizing guide for 250w ebike.

What size battery is perfect for a 350w e-bike

For choosing the battery for the 350W ebike, let’s first see the ebike motor types. There are mid-drive motors and hub motors. These two types are differentiated based on the placement of the motors.

When the motor is placed in the crank of the e-bike it is mid-drive and when the motor is in the front or rear wheel’s hub then it is called hub-motor. The mid-drive motor accelerates faster than the hub motor.

An e-bike with a 350-watt motor would need at least 350-watt input power from the battery. The majority of 350w electric bikes have 36v batteries as the motor’s required voltage is also 36 volts.

Therefore, you should opt for a 36v battery with an Ah ranging from 10Ah to 15Ah. A 36V 10Ah battery would provide a lesser range than the 36V 15Ah one.

But in cases when nothing is mentioned on the e-bike motor? Then always pair the bike with the 36V 12Ah battery. It comes between 10 to 15Ah and is capable of providing enough charge to cover distances like 30 miles.

But don’t forget to take into consideration a few factors before you go ahead and make the choice. The factors, such as your weight, the terrain, the distance, etc.

Must read: How fast can a 350w ebike go?

What size battery is best for a 500w ebike?

Firstly, the battery voltage is one of the most important factors when choosing the correct battery size. The recommended minimum voltage for a 500W ebike is 36 volts and some ebikes have 48 volts.

I have already mentioned above that the voltage of the battery is responsible for the entire bike’s performance i.e., speed. A higher voltage battery provides more speed on various terrain and vice-versa.

Secondly, the battery capacity i.e., Amp-hours (Ah). It is responsible for how much current it can store,  higher Ah stores more current and lower Ah stores less current. So what configuration battery is perfect for your 500w ebike?

The minimum battery capacity (Ah) for a 500w is 10Ah and the maximum recommends Ah is 20Ah. Select the voltage according to the motor’s input power (voltage), it will be either 36 volts or 48 volts.

In my experience, a 36V 15Ah battery is perfect for a 36v 500w electric bike, and if your 500w ebike has a 48v motor, pairing it with a 48v 10Ah battery will be perfect.

However, If you need more range, You can go with a higher Ah battery as long as you are comfortable with the added weight which becomes the companion in their rides.

Always, Choose a lithium-ion battery to reduce weight without compromising the quality and range of the batteries.

Also, you need to choose a battery that has temperature management systems. Depending on the weather it can become too hot or too cold hence it is crucial.

What size battery for a 750w electric bike?

Let’s get the basics first. A 750W battery would need 750 wattages of power per hour from the battery. And to choose the correct ebike battery size we have to multiply the volts and the ampere-hour to see the right size. Not forgetting the other factors that we discussed earlier.

Hence, for a 750W bike, a 48V with 16Ah is ideal. It won’t affect the bike in any negative ways and will give you a smooth ride. Also, a smaller bike for this much of a high-wattage bike is never ideal as it would affect the bike negatively.

We always choose the capacity by keeping the ideal case and the things we need in a bike. If you want longer distances you have to go for higher capacity (Ah) batteries with the same voltage but by not overdoing it!!

Do you know the top speed of a 750w ebike? let’s discover how fast can a 750w ebike go on various terrains!

What size battery for a 1000w electric bike?

A 1000W ebike offers an amazing speed of approximately 35 mph on paved roads and this kind of speed will be unlocked when it is paired with a correct voltage battery.

Two options go the best for this bike, 48V 20Ah and 52V 20Ah. The first one is generally good and gives around 960 watt-hours but if you want to get the extreme out of your bike, go with the second option only when your ebike motor & controller support a 52v battery.

As we have already seen for other bikes, in this one too a 1000W bike would need a power of at least 1000 watts in an hour from the battery. In order to calculate the watt-hour of the battery we will have to multiply the battery’s voltage by the Ah of the battery.

Generally, a 48V battery does the work in a 1000W battery but we should keep in mind the capacity too because choosing a low-capacity battery for your ebike can lead to less range (distance) leading you to recharge it again and again. It means a higher-wattage ebike needs a higher Ah battery and vice versa.

Read this detailed guide on what size battery is for your 1000-watt ebike. How to calculate the correct battery voltage & AH?

What size battery for a 1500w ebike?

After going through all the above bikes, we have got a hold of how to calculate the right battery size for electric bikes. We will apply the same applications that we have learned over time in this blog.

The first thing we would see, yes you got that right, what voltage does a 1500w ebike motor need? This is mentioned on the motor itself. If not, contact the manufacturer, and they will tell you.

Well, the majority of electric bikes with 1500w motors have a voltage between 48v to 60 volts. 48v 1500-watt motor is less powerful than a 60v 1500w ebike motor. Yes! You are right because of the higher voltage.

Once you know the voltage of your ebike motor, you will need to decide upon AH. The battery capacity for a 1500w ebike should be around 20Ah to 30Ah.

Here is the table showing the best battery combinations for your 1500w ebike with their respective range:

Ebike Battery SizeExpected Range
48V 20Ah30-40 miles
48V 25Ah40-50 miles
48V 30Ah45-60 miles
52V 20Ah30-40 miles
52V 25Ah35-50 miles
52V 30Ah45-60 miles
60V 20Ah30-45 miles
60V 25Ah40-60 miles
60V 30Ah50-70 miles

You can decide the battery voltage & AH from the above-mentioned table according to your needs. Always remember, a battery with higher Ah is expensive as well as it adds extra weight to the ebike which reduces the ebike speed a bit.

You must read: How fast can a 1500-watt ebike go?

What size battery for a 2000w ebike?

What size ebike battery do I need for my 2000w electric bike? The right battery fitted for the 2000W e-bike is 52V 40Ah or 60V 30Ah. After all the things we have discussed here, I am sure we can find the logic behind choosing this battery!

“As the motor of the bike is high power we would need a high power battery and hence we make this choice”

We cannot go for too low and too high powered batteries because of the damage that they bring. We have calculated the perfect battery size for a 2000w ebike by using the same method that we used above and found the three volts that can go with these bikes are 52V, 60V or some bikes can go with 72V too. This depends on your motor voltage.

During my research, I have found that the majority of 2000w electric bikes have either a 52v motor or a 60v motor. I am sure, you would have either one of these. Make sure to match the voltage otherwise, you won’t realise the top speed potential of your 2000w electric bike.

Talking about the Ah, the minimum Ah should be 30Ah whether you go with a 52v battery or 60v battery. The expected range would be around 30-50 miles on a single charge.

What size battery for a 3000w ebike?

This time a lot of things are taken into consideration to decide the best battery size for a 3000w ebike but the thing that highlights and makes a 3000W bike different from other bikes is that it is very powerful & strong.

As it is very powerful hence it consumes a significant amount of energy during its ride. But the power consumption too depends on several factors such as the riding style, the kind of area it’s ridden on, and so on.

The majority of 3000w ebike motors need either 60V or 72V input power from a battery. This is only possible when it is paired with the same voltage i.e., 60 volts or 72 volts.

And the next question is what Ah battery is best for a 3000w electric bike?

Well, it totally depends upon your requirements. How far you will travel and at what speed?

In my experience, you should go with a 30Ah battery if you are okay with 50-70 miles. Otherwise, you can go with a higher Ah battery if you need more range. But will cost you much as well as increase your bike’s weight.

So the final decision is in your hand. Think wisely!

Well, You can also calculate the other options by increasing or decreasing the volts and capacity based on your needs.

However, the same thing would be applied here too that we should not choose too low a battery for this because we know 3000w ebike is a high-powered bike and would need a battery that would complement the motor and not something holding it back and result in not unleashing its true potential.!!

Must know: How fast can a 3000w ebike go? Let’s find out the top speed

Factors Affecting Ebike Battery Size (Volts & AH)

So, after looking at how to calculate battery size for electric bikes with various wattages and looking at some examples too, now is the time to understand how Volts and Ah affect the batteries.

We have already seen the factors such as weight, terrain, distance, and temperature, and how all these factors affect the size of the battery but now we will delve into the depths of Volts and Ah.

From the previous understanding, we know that Voltage is the amount of electrical force that the battery can produce, which is responsible for the performance of the ebike i.e., Speed.

Whereas, Ah stands for Amp-hours, which indicates the amount of charge the battery can have per hour. It is also known as the capacity of the battery showing the amount of energy it can store.

A higher Ah battery stores more energy & vice-versa. Which directly affects the range of the battery on an ebike. For example, a 20Ah battery has more range than a 10Ah battery on an ebike.

Only Volt is not important, you need to decide upon both of the factors. So Basically, Volts, Ah & Watt-hours do not operate independently, they are all dependent on each other.

Always remember, The more the Ah the longer the bike can go, the more the Volts and power the better the acceleration, and the speedier the ebike can go.

If you want better performance (speed) & longer distances (range), choose a battery with higher volts & Ah respectively.

Conclusion on the Ebike Battery Size Guide

In this extensive blog, we dealt with the concept of ebike battery size (voltage & Ah) covering the basics to advanced. I hope you have understood “what size battery is best for electric bikes” and learned how to calculate the correct battery size for an ebike.

When your ebike is paired with the correct battery voltage & AH, you enjoy riding your bike because you easily cover your desired distance at your speed. That’s what an ebike user expects from his/her ebike.

The factors that affect the decisions should be kept in mind and should be addressed properly, and then battery volts, power, and Ah can be taken into consideration!

Many examples have been provided for you to get a better idea of how the theory works and each example has been well defined for the same reasons.

Frequently Asked Questions (FAQs)

Q1. Are electric bike batteries universal?

No! ebike batteries are not universal. It means you can’t put any battery in any ebike. There are certain parameters, and one of them is voltage. Every ebike operates on a certain voltage such as 36v, 48v, or 52v. So only the correct voltage battery pack will match and perform excellently on your ebike.

Q2. What are the available battery voltages for ebikes?

For electric bikes, the minimum recommended battery voltage is 24 volts and the maximum battery voltage is 72 volts. Battery voltage totally depends on the voltage of the ebike motor. A higher voltage battery increases the performance of the ebike and hence, boosts the e-bike’s speed.

Q3. What is the average battery capacity of an electric bike?

Battery capacity depends upon the ebike motor wattage. But the majority of ebikes operate on 48 volts. Keeping this point in mind, I would say a 48v battery with a minimum of 10Ah capacity works fine on 500W & 750W ebike, and you can increase the Ah accordingly. Scroll above for the battery size for each ebike.

Q4. Can I make my ebike faster with a bigger battery?

Do remember, you can make your ebike go faster only when you increase the battery voltage if your ebike motor & controller is compatible with the higher voltage battery. Higher Ah will only increase your range, not the speed.

Q5. Can I put a higher voltage battery on my ebike?

You can put a higher voltage battery on your ebike only if the motor & controller are compatible with the higher voltage battery. Otherwise, your ebike motor will be damaged due to excessive power supply by the battery.

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I am the founder and editor of The Bike Fetcher, a passionate E-Biker. My passion for E-bikes led me to build this blog site where I share electric bike news & updates, my e-biking experience, e-biking tips, e-bike battery tips and help people to get the best e-bike. Feel free to contact me on my social accounts or through the contact form.

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