Can I Add a Second Battery to My eBike? (Parallel Vs. Extra)
One time, I was having a great time riding my electric bike, and I didn’t notice it running out of battery. So, when I got back home, I took some time to research if I could add a second battery to my electric bike?
As a whole, you can add a second battery to your electric bike. You can choose to bring an extra battery during your ride, or you can connect the two batteries in parallel.
As electric bike riders, we always want to maximize our range to enjoy our electric rides to the fullest. This article will explore ways to extend the e-bike range, such as battery parallel connection and bringing an extra battery. We will also address some common questions about adding a secondary battery to an electric bike.
Can I Add a Second Battery to My eBike?
Adding an extra battery to your electric bike is entirely feasible. However, it’s essential to consider a few key factors:
- Where do you intend to position the additional battery?
- What battery do you plan to use?
- Are you leaning towards connecting the batteries in parallel or utilizing it as an extra battery?
Position of Your Secondary eBike Battery
The positioning of your secondary e-bike battery is a crucial aspect to consider before making a purchase. It’s essential to assess whether adding a secondary battery to your electric bike is feasible and whether it might impact your overall riding experience. Here are some considerations and potential positions for your secondary electric bike battery:
- Check whether your electric bike has adequate space for a second e-bike battery. Some electric bikes may have large areas, while others may not, depending on the e-bike frame design and style. There are also electric bikes that feature mounting points for a second battery, in case you decide to add one.
- Evaluate the chosen position for the second battery to ensure it doesn’t interfere with your riding or other components of your electric bike. Make sure that positioning the secondary battery in that space will allow your comfort and the e-bike’s functionality.
- Some common designated positions for the second battery include the down tube, top tube, rear rack, seat post or tube, and pannier bags.
- If your electric bike has limited space, opting for a smaller battery that can fit comfortably in your desired position is better.
- Always choose a position where you can aim for a balanced setup, ensuring your battery’s weight is distributed properly. It is essential to note that overall weight distribution can significantly affect your e-bike’s performance, stability, and comfort.
Choosing the Right Battery for Your Electric Bike
Batteries for electric bikes come in diverse sizes, shapes, styles, weights, capacities, and prices. Therefore, when considering the addition of a second battery to your electric bike, it is essential to plan which type of battery suits your preferences and needs.
Battery shapes vary and can include triangles, rectangles, cubes, kettle-shaped, water bottle shapes, and more. Some batteries can even be customized according to your liking. Additionally, e-bike batteries differ in capacity, so selecting a battery that aligns with your riding requirements is crucial. For instance, choosing a second e-bike battery with the same capacity as your primary battery would be beneficial if you want to double your range. However, it’s worth noting that higher-capacity batteries are often larger, heavier, and more pricey than lower-capacity batteries.
Another consideration is the battery protection system. Some batteries come with a hard protective case or cover, while others are wrapped in shrink wrap. There are also batteries mounted on the e-bike via an e-bike mounting plate or bracket, making it easy to remove. Many of them feature a locking mechanism for theft protection.
Determining your budget in advance is advisable, allowing you to choose a battery pack that fits within your set budget. Furthermore, if you value the overall style of your electric bike, it’s a good idea to look for an electric bike pack that blends seamlessly with your e-bike’s aesthetics.
Here are some e-bike battery packs you can purchase:
| eBike Battery Pack | Battery Capacity | Voltage | Cost | Where to Buy |
| S045 52V 20AH 1040WH BMS40A Ebike Li Ion Battery | 1,040Wh | 52V | $439 | Link |
| U004 Triangle Ebike UPP Battery | 960Wh | 48V | $368 | Link |
| 20Ah BMS40A/50A D034 Li Ion Battery | 1200Wh | 60V | $366 | Link |
| 48V 16AH 768WH BMS30A (LG3200 CELL) | 768Wh | 48V | $389 | Link |
| 48V13Ah Uzi eBike Battery Conversion KIt | 624Wh | 48V | $269 | Link |
| 52V18Ah Uzi eBike Battery Conversion KIt | 936Wh | 52V | $387 | Link |
| ENGWE Unit Pack Power 48V 13AH Ebike Battery | 624Wh | 48V | $249.68 | Link |
| QWW 48V 17AH EBike Battery Pack | 816Wh | 48V | $269.98 | Link |
| QWW 36V 10AH Electric Bicycle Lithinum ion Battery Pack | 360Wh | 36V | $179.99 | Link |
| 52V 14.5AH Jumbo Shark eBike Battery (2900 18560 Cells) | 754Wh | 52V | $649 | Link |
| 48V 14AH Ultra Slim Shark eBike Battery (LG 3500 18650 Cells) | 672Wh | 48V | $699 | Link |
| eBike Battery 72V 8Ah | 576Wh | 72V | $469 | Link |
Preferred Usage: Parallel Connection or Extra Battery
The next consideration is how you plan to use your second electric bike battery. Will you connect the two batteries in parallel, or do you see the second battery as an extra battery for extended range when needed? The decision depends on your preferences and your e-bike’s frame design and style. It’s essential to note that these two approaches have advantages and disadvantages.
Some riders choose to have a second battery solely as a spare one for situations where the primary battery’s capacity may not be sufficient. You can carry it using saddlebags, pannier bags, or backpacks or mount it on an available battery mount bracket or holder. However, in cases where you’re running errands within a distance that your primary battery can handle well, you may leave the second battery at home to avoid adding extra weight to your electric bike. This approach is suitable for e-bikes with limited space for a secondary battery.
However, when using this second e-bike battery as a spare one, it’s crucial to consider the compatibility of your secondary battery, especially since most e-bike batteries are mounted on a mounting plate. In this case, if the second battery does not fit perfectly on the mounting plate of the primary e-bike, then you might not be able to use it.
Using a secondary e-bike battery as an extra does come with a slight disadvantage. For instance, it could be inconvenient to stop in the middle of your ride just to replace your e-bike battery.
Another approach you can consider when purchasing a secondary e-bike battery is connecting the two batteries in parallel. This method offers better convenience because you wouldn’t need to stop your ride and replace your primary battery when drained, as you can use the two batteries simultaneously. This is preferable for e-bikes with sufficient space for a second battery.
However, for this approach, you would need a battery parallel connector, incurring additional costs. Moreover, since you’ll be connecting two batteries in parallel, it’s crucial to note that the voltage of the two batteries must match. They may have different amperages, but their voltage should be the same. Connecting batteries with different voltages may lead to battery damage or, in extreme cases, battery explosion. Therefore, if your primary battery has a voltage of 52V, ensure that the secondary battery you purchase has the same voltage to prevent accidents. However, if you want to connect batteries with different voltages, use a smart dual-battery blender that monitors and regulates the voltages of the two batteries.
Connecting two e-bikes in parallel could have a slight disadvantage because it adds extra weight to your electric bike. Therefore, choosing the right battery size and mounting it in the correct position is essential to ensure proper weight distribution.
While these approaches enable you to extend your range, it’s also important to note that the charging cost of your e-bike may also double.
Here are some of the e-bike battery parallel connectors you can purchase online:
| eBike Battery Parallel Connector | Cost | Where to Buy |
| Dual Battery Parallel connector | $59.99 | Link |
| SUNGOOYUE Dual Battery Parallel Module Adapter | $42.12 | Link |
| Dual Battery Connector | $48.69 | Link |
| Higo Double Battery Discharge Converter for E-Bike | $46.35 | Link |
| Battery Blender | $150 | Link |
Can You Use Two Batteries on an eBike?
As a general rule, you can use two batteries on an electric bike. You can connect the two e-bike batteries in parallel or bring the other e-bike battery as a spare battery and use it once the other battery is drained.
Using two batteries on an electric bike allows riders to extend their range, enabling them to enjoy a longer and more satisfying electric ride without worrying about running out of battery.
Opting for two electric bike batteries is ideal for riders seeking more range. However, despite the considerable advantage of covering more distance, it’s essential to note a few drawbacks, such as longer charging times and higher charging costs. Moreover, acquiring a spare battery can be relatively expensive. Hence, budget considerations are crucial when planning to purchase a second battery.
Furthermore, for those who still need to invest in an electric bike, it’s worth mentioning that some models on the market come equipped with a dual-battery system. Purchasing an electric bike with a dual battery eliminates concerns about choosing a secondary battery, worrying about its placement, and deciding on its usage, providing a more seamless and convenient experience.
Here are some of the electric bikes on the market that feature a dual-battery system:
| Electric Bike | Cost | Battery Capcity | Range | Motor Power |
| Packa Genie Cargo Electric Bike | $1,999 | 1,228Wh | 80 miles (128.7 km) | 750W Nominal, 1,350W Peak |
| Dubbel Utility Electric Bike | $2,099 | 1,228Wh | 80 miles (128.7 km) | 750W Nominal, 1,350W Peak, 90Nm torque |
| Ultra All-terrain Electric Bike | $2,099 | 1,334Wh | 80 miles (128.7 km) | 750W Nominal, 1,350W Peak, 90Nm torque |
| XPedition Dual-Battery Cargo eBike | $1,599 | 1,345Wh | 150 miles (241.4 km) | 750W Nominal, 1,310W Peak, 85Nm torque |
| GRAOOPRO Electric Bike | $2,598 | 1,920Wh | 210 miles (338 km) | 750W Nominal, 1,000W Peak |
| Engwe M20 Electric Bike | $1,199.99 | 1,248Wh | 94 miles (151.3 km) | 750W Nominal, 1,000W Peak |
| XPremium Black Electric Bike | $1,599 | 1,000Wh | 100 miles (160.9 km) | 500W Nominal, 800W Peak |
Can You Run 2 eBike Batteries in Parallel?
On average, you can run two electric bike batteries in parallel, allowing them to function as a single power source. This means you can use both batteries simultaneously, effectively extending your range. This helps ease worries about running out of battery power during your ride.
When planning to connect two e-bike batteries in parallel, it’s essential to note a few considerations. First, ensure that the voltage of both e-bike batteries is the same. If your primary battery is rated at 48V, it’s highly advisable to use a secondary battery with the same 48V rating. Using a secondary battery with a different voltage may lead to battery damage or, worse, battery explosion.
For example, if your primary battery has a voltage of 48V and the second battery has 52V, connecting them in parallel with a standard parallel connector can cause issues. The higher voltage will discharge rapidly, and the lower voltage will quickly charge at rates both batteries cannot handle. In this case, the battery cells may not handle the current, resulting in permanent damage or explosion. However, the amp-hour capacities of these batteries could still be different.
Secondly, you’ll need to purchase a parallel connector for the batteries to work simultaneously. It’s worth mentioning that some sources suggest the possibility of connecting two e-bike batteries with different voltages, but this would require using a smart dual-battery connector or a battery blender to monitor and equalize the charge of the two batteries. You can check out the Sparkcycleworks battery blender here, which costs $150.
“More range means more fun.”
-electricrideowner.com
How Do You Parallel eBike Batteries?
As a whole, you can parallel electric bike batteries by using a dual-battery parallel connector. Ensure that the positive and negative sides of the two batteries are connected properly, and then connect the connector to the e-bike’s motor.
So, the very first things to prepare are the dual-battery parallel connector and the secondary battery. When connecting e-bike batteries in parallel, it’s crucial to consider the voltage rating of the two batteries. It is highly recommended to connect two batteries with the same voltage to avoid potential damage to the batteries or any possible incidents.
Secondly, look for a parallel connector that perfectly fits the connectors of your electric bike batteries. Note that battery connectors may vary, so checking them before searching for a parallel battery connector is recommended. Furthermore, if you plan on connecting two batteries with different voltage ratings, it is advisable to look for a smart dual-battery connector or battery blender that monitors and regulates the charges of these two batteries.
After preparing the batteries and connector, check for the space for the secondary battery. Ensure the location won’t hinder your comfort or the e-bike’s functionality. In most cases, the dual-battery parallel connector has three connections. Two are for the two e-bike batteries, and the other goes to the motor controller.
Once everything is set up, you can start your electric bike ride and enjoy your extended range!
You can also watch the video below for a guide on adding a secondary battery to your electric bike.
How to Carry Spare eBike Battery?
As a general rule, there are several methods for carrying a spare electric bike battery on your ride. Some of these include:
- Battery mount
- Frame-mounted bags or battery holders
- Under Seat Saddlebag
- Rear rack bags or pannier bags
- Backpack
1. Electric Battery Mount
Some electric bikes in the market come equipped with built-in battery mounts designed for a secondary battery. If your electric bike has this feature, you can directly mount your spare battery onto the designated battery mount, eliminating the need to purchase a separate battery holder or bag.
If your electric bike doesn’t have this feature, you can purchase a battery mount for your e-bike. Here are some e-bike battery mounts available on Amazon:
| eBike Battery Mount | Cost | Where to Buy |
| Drift Maniac Ebike Conversion Kit for Battery Adapter Frame Mount | $20.59 | Link |
| Grin Technologies Triple Bob Ebike Battery Anchor Bracket Mount | $33.98 | Link |
| FcotMiue Polly Shark DP-6 DP-9 Electric Bike Battery Bottom Base Bracket Holder | $32.99 | Link |
| Accolmile Bike Battery Base Bottle Cage | $17.97 | Link |
2. Frame-Mounted Bag or Battery Holder
Some electric bike riders aim to extend their range. As a solution, many choose to purchase a spare battery in case the primary one is drained. Several companies have designed battery bags and holders to accommodate this need, allowing riders to carry extra batteries while riding.
Frame-mounted bags or battery holders typically come with straps that can be securely attached to the e-bike frame. They come in various shapes and sizes, allowing riders to choose the one that perfectly fits their e-bike battery.
Here are some frame-mounted bags or battery holders you can find on Amazon.
| Frame-mounted Bag/ Battery Holder | Cost | Where to Buy |
| Himiway IP65 Waterproof Bicycle Frame Bag | $9.99 | Link |
| Newboler Waterproof Bicycle Triangle Bag with Two Side Pockets | $27.19 | Link |
| Kemimoto 2-in-1 eBike Battery Bag | $23.99 | Link |
| Rockbros Bike Frame Bag | $22.39 | Link |
| Rhinowalk Waterproof Bicycle Triangle Bag | $25.59 | Link |
| BiKase EBike Battery Bag | $39.99 | Link |
| Blackburn Outpost Bike Frame Bag | $52.45 | Link |
3. Under Seat Saddlebag
If you have a spare electric bike battery and there is enough space under your e-bike saddle, you can purchase a saddlebag that can be positioned under the seat. Here are some options you can consider:
| Rear Rack Bag or Saddlebag | Cost | Where to Buy |
| Rockbros Waterproof Bike Saddle Bag | $50.99 | Link |
| Rhinowalk Waterproof Bicycle Under Seat Bag | $31.99 | Link |
| Obova Bike Seat Bag Waterproof | $18.99 | Link |
| Roswheel Waterproof Bike Saddle Bag | $23.99 | Link |
| Thrlegbird Waterproof Bicycle Bag | $24.99 | Link |
4. Rear Rack Bag or Pannier Bags
You can also carry your spare electric bike battery in e-bike pannier bags, which can be mounted on the front or back side of your electric bike. Here are some options you can consider purchasing:
| Rear Rack Bag or Pannier Bags | Cost | Where To Buy |
| Kemimoto Rear Rack Bag | $19.99 | Link |
| Vitilan Bike Rack Bag | $69.99 | Link |
| Anmeilu Bike Rack Bag | $12.79 | Link |
| West Biking Bike Rack Bag | $38.49 | Link |
| Mosiso Bike Rack Bag with 2 Removable Bike Panniers | $26.39 | Link |
| Mimoke Electric Bike Battery Bag | $21.99 | Link |
| Waterproof Bicycle Saddle Panniers with Extra Padded Foam Bottom and Side Reflectors | $31.99 | Link |
5. BackPack
You can also put your spare electric bike battery inside a backpack. Any backpack will do, as long as you are comfortable carrying it while riding. If you have a backpack at home, you won’t need to buy one, so you can save money.
How Do I Extend My eBike Battery?
On average, you can extend your e-bike battery range through the following methods:
- Adding a second battery connected in parallel
- Using a lower pedal assistance level
- Choosing the right area or route
- Maintaining a moderate speed
- Avoiding excessive weight
- Smart charging
1. Adding a Second Battery to Extend Range
One effective method to extend your battery range is by adding a second battery to your electric bike and connecting the two batteries in parallel. This increases your overall capacity, potentially resulting in a more extended range depending on the added capacity. While this approach is practical, it’s worth noting that it may come with a significant cost, as you’ll need to purchase a spare battery and suitable parallel connectors for the two batteries to work simultaneously.
2. Adjust Your Pedal Assist Level Depending on Your Needs
In many cases, using a lower pedal-assistance level can help you extend your range. If there’s no need for a higher pedal-assist level, consider riding your electric bike at a lower assistance level to cover more distance. Not only does this contribute to extending your range, but it also provides the added benefit of increasing your fitness.
3. Choose the Area or Route Where You Ride
This method is particularly suitable for riders who prefer less adventurous and thrilling rides, such as mountain biking or those with numerous inclines. If you’re not aiming for such rides, consider riding on smooth pavements. This practice helps conserve battery energy, likely extending your range. Riding in areas with bumps, inclines, or rough roads can significantly drain your battery, reducing your overall range.
It’s also beneficial to choose routes where there are possible charging stations. This way, if your battery power runs low, you can quickly charge your electric bike and continue your ride.
4. Ride at a Lower Speed to Go Farther
Electric bikes come with varied maximum speeds. Some may have a top speed of 20mph (32kph), while others are even faster. If your electric bike’s full speed is 20mph (32kph), consider riding lower than that to increase your range and cover more distance.
5. Do Not Carry Excessive Weight
The overall weight that an e-bike carries can also affect its range. If you are a heavier rider or carrying a substantial load, your range may be shorter than usual. So, as much as possible, avoid taking excessive weight when riding your electric bike to maximize your distance.
6. Charge Your eBike Smartly
Smartly charging your electric bike is another way to extend your battery’s range and lifespan. Before embarking on an e-bike ride, estimate the distance you plan to cover. Whenever possible, avoid completely charging and discharging your electric bike. Optimal charging involves charging up to 80% and discharging to 20-30%. Occasionally, perform a full discharge and charge cycle to maintain your e-bike battery’s performance. Keeping its performance at its peak ensures that your potential range won’t be negatively affected.
If you are interested in having a more expanded insight about the battery’s mileage and lifespan, you can visit our article “How Long an Electric Bike Battery Last [Lifespan, Per Charge].”
