What Size Battery for 250W Electric Bikes? An Ultimate Guide

A 250w ebike is lightweight and best for beginners to start their electric biking journey. So you got a 250w ebike motor for an effortless, faster, and more convenient commute but you are not getting your desired range and struggling to ride on inclined surfaces.

It’s most probably your e-bike’s incorrect battery size that is coming in between you and your rides. You might have bought an ebike or converted your normal bike with the wrong battery size.

Don’t worry! I would explain and guide you about what size battery for 250w ebikes is perfect.

It is often seen that riders are primarily confused about which ebike battery size to install according to the capacity of their electric bike motor.

Does the use of a higher capacity battery improves your e-bike speed or affects it negatively?

How could you calculate the correct battery size according to your ebike wattage? How could you protect your motors by sticking to these healthy battery operating habits?

These are the exact things that we are going to talk about in this article, so stick around to know which is the perfect battery size for your 250w electric bike.

What Size Battery for 250w Ebikes? Factors to Consider

Getting to know how the battery of your ebike operates and how much capacity it holds to power your 250w e-bike motor is one of the first and most prominent steps while deciding upon the perfect-size battery.

A 250w ebike motor needs at least a battery that can provide minimum power of 250 watts in an hour. Generally, most brand-new 250w ebikes come with a 36v 10Ah battery pack i.e., 360 WH.

However, ebike battery size depends on your riding distance, the surface you ride on, your weight, etc. You must consider all these factors while selecting a perfect battery capacity for your 250w electric bike. Let’s understand in detail.

Related: How Long to Charge a 48v Ebike Battery?

How to calculate the correct battery size for a 250w Ebike? Importance of Amp Hours (AH) in ebike battery?

battery size for a 250w Electric bike

There’s a square and round method by which you can calculate the correct battery size for your 250-watt e-bike motor. When we say, calculating the correct battery size it majorly means the best-fit battery according to your usage.

Whether you need more energy or less and higher, how many miles you will be riding generally, and so on. It all depends upon the battery’s Watt-hours.

So, the Watt-Hours are what define the size of the battery. Watt-hours (Wh) is the Power Demand per distance traveled (Wh / mile or km) multiplied by the typical Distance Traveled (miles or km).

For example, a 10Ah battery and a 36 V battery have a capacity or size of 360Wh (36v x 10Ah).

Now, most of the motors have already mentioned the appropriate voltage demanded on them. Majorly 250w e-bike motors require a minimum of 36V battery.

What most people miss while choosing the correct battery size for a 250w ebike is the ampere-hours (Ah), which is an indication of the capacity of a battery. To simplify, remember that the higher the Ah rating of the battery, the more energy it can store and the longer it will last/go.

Hence, if you are aiming at longer rides then we recommend going for a 10.4 Ah to 13 Ah with a 36v battery pack.

We understand that it is quite normal to get confused between battery terminologies such as voltage, amp hours, watts, the electricity drawn, and all that, but it just takes one try to get the hang of the simple math.

How to know the battery power capacity of your ebike?

From the above two factors, the voltage range and current drawn while powering the motor you can easily calculate the capacity or size of your e-bike battery.

Further, you can implement these factors to figure out how far your battery can run by dividing the amperes and current drawn. Hence, while deciding upon what size battery for 250w ebike.

Can a Wrong Battery Size Hamper an Ebike’s Functioning?

Where most riders are banging their head in evaluating all the possible factors on point and choosing the perfect size battery for their 250w electric bicycle, some riders seem to care less about what battery size they are using until and unless it’s doing the job.

However, the idea of “a battery that charges up quickly” might not be ideal.

A battery that is not best suited for your e-bike can bring down the performance of your bike along with having negative impacts on its components.

For say, a smaller battery size might not power your e-bike efficiently and drag down the motor and heat up in no time.

Similarly, a battery too big for your 250w e-bike could result in hampering the balance because of its weight and other components might have dysfunctionality because of high power which leads to costly maintenance.

Factors Affecting Battery Size for a 250w Ebike

As you know a 250w electric bike needs at least 250 watts of power from the battery pack to perform perfectly. However, a 250 WH battery doesn’t deliver the desired power because of the following factors or reasons:

Factors Affecting Battery Size for a 250w Ebike

1. Battery voltage

Generally, most brands mention the required voltage on their ebike motor which makes your battery size selection task easy. What if you don’t find it?

You can very easily determine the voltage that your 250w ebike motor needs by dividing the power (say 250w) by the current needed to operate the motor (say 10-amps).

It means, your 250w ebike motor can be easily operated with a 24v battery. But we would recommend you to go with a 36v ebike battery as it will offer more distance and do not affect your ebike motor.

Don’t go with more than 36 volts for a 250w ebike motor, If you do so it would cost you much and your battery would not discharge properly which is not a good thing for maintaining the battery’s health.

2. Battery capacity (Ah)

Amp-hour of an ebike battery is its capacity. Higher AH stores more electric current in the battery and thus provides more riding distance. We recommend going for a somewhere between 10 to 13 Ah battery with a 36v battery.

Don’t go for more than that because a higher Ah battery increases the weight of the bike, that capacity is not needed by the 250w ebike motor.

3. Controller capacity

The controller of an ebike decides the maximum current output to the motor. It’s very important to consider the controller amp rating equivalent to the battery’s AH. A controller with a 10 to 15 amp rating is enough for a 250w ebike.

3. Rider’s weight

Once you decide on the battery voltage and AH, you should also consider your weight while selecting a battery for a 250w ebike motor. If your weight is high (say around 80-100kg), you need a higher AH (say 15AH) battery because your weight would increase the load on the motor.

4. Purpose and place of riding

A 250w ebike is best for commuting on plane roads. If you have got this for the same, you should go with a 36v 10Ah battery pack. However, if you face some inclined surfaces and carry some loads, you should get a 36v 15Ah battery pack.

5. Battery mounting options

Ebike batteries can be mounted on the frame downtube, rear rack, seat tube, or on top tube of the frame. Big size battery takes extra space as compared to a small-size battery. So, go for a compact-size battery or integrated battery which takes very less space making your ride comfortable and convenient.

Why Get a Dynamic Ebike Battery

Now that you know how to choose the correct battery size for your 250w ebike, there are other factors that you can consider to not only increase your e-bike battery’s performance but also head towards an excellent one!

  • Battery type: There is multiple chemical composition available in ebike batteries, from lead-acid to nickel-metal, however, lithium-ion is one of the most loved and preferred by riders all over the world.
  • Weight of the battery: You should always naturally opt for a lightweight battery since over time heating and overuse leads any battery to swell up and become heavier.
  • Price: Do not compromise on the quality of your e-bike battery. The cheap batteries not only stop working soon but also harm the motors of the bike. Always purchase a UL-certified battery.

Apart from these, the necessary factors like voltage, capacity, warranty, and brand are a few other things that you must consider while choosing an e-bike battery.

How to Utilize Your E-bike Battery to the Fullest?

Only operating on the correct battery size would not make your e-bike high performance, what truly matters is how well you maintain your e-bike battery for a long run and consistent performance.

Here are a few of our tried and tested tips for an efficiently powering battery:

1. Using BMS

BMS or battery monitoring system is a technology that helps in regulating battery charging and durability. It helps in reminding to charge the battery once it’s drained up to 35%. This will remarkably be a healthy e-bike battery habit.

2. Using the right charger

This is such a simple yet crucial point. Often people do not use the manufacturer’s charger and opt for any charger, this is one of the major reasons that hamper your battery’s performance.

3. Avoiding extreme temperature

Exposing your e-bike battery to an extreme climate like negative cold to high heat can result in your battery swelling up or halting mid-rides. Apart from this most e-bike batteries are water-resistant, but we still recommend not leaving them in the rain.

4. Don’t drain to zero

Always make sure that you recharge your battery before it is fully drained and drowns to 0% since it is really risky and hampers the shelf life of your battery.

Conclusion on What Size Battery for 250w Ebike

We understand the confusion and tension about choosing the correct battery size for your e-bike since it plays such an important role in regulating your e-bike and especially in the long term.

We hope that our summarized article on how to choose the correct battery size for your 250w ebike will help you get clarity and a good e-bike battery.

Along with that, we aim to spread as much knowledge about e-bikes as possible!

Keep Riding and Keep Learning!

Frequently Asked Questions (FAQs)

Q1. Can I use a 500w battery on a 250w ebike?

It’s not recommended to use a higher-wattage battery than your motor’s wattage. So, a 500w battery is very powerful for a 250w ebike motor (250w extra power which would be unused). As well as the controller of a 250w ebike is not compatible with a 500w battery, so don’t waste your precious money. Generally, a 500w battery is paired with a 350w and 500w ebike motor.

Q2. How long does it take to charge a 250w ebike battery from empty to full capacity?

There are three factors that determine the charging time of a 250w e-bike battery from empty to full: the type of battery, its capacity, and the charger used. However, on average, it takes between 3 to 6 hours to fully charge a 250w electric bike battery from zero.

Q3. Can I use 48v battery with 250W motor?

Yes, you can but not recommended. Because a 48v battery with a minimum 10 ah capacity is around 480 watt-hours which are very powerful for a 250w ebike motor, if you do so your money will be wasted and your bike’s weight will increase and battery power will be unused if you don’t ride it for 45 to 50 miles per day.

Q4. Can you use a 350w battery on a 250w motor?

Yes, you can use a 350w battery on a 250w ebike motor. Most ebikes come with a configuration of 36v 10 Ah battery with a 10-Amp controller which is coming out to be 360 watts. So you can also go with it but don’t go more than this.

Q5. What battery do I need for a 24v 250w motor?

For a 24v 250w electric bike motor, you will require a minimum of 24v battery with a capacity of at least 10Ah to 13Ah (amp-hours) to power the controller to the motor. However, It is important to note that the type of battery you will need will depend on your specific e-bike model and its requirements.

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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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