How to Repair Electric Bike Battery [A Step-by-Step Guide]

Whether you are a new e-bike owner or someone who has already been a fan of the invention since its launch in the United States, the sheer volume of things to know about the electric bike battery can be overwhelming.

Being one of the most critical components of your electric bike, an e-bike battery plays an essential role in keeping you on the road. However, like every other mechanical creation, it won’t last forever.

Eventually, failure will occur. Therefore, in situations like these, it is essential for every e-bike owner to know how to repair electric bike battery to continue riding their bike without any inconvenience. Here’s everything you need to know!

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What Causes an E-Bike Battery to Die?

Before we move on to how to repair electric bike batteries, it’s important for you to learn what causes your electric bike battery to malfunction in the first place.

Nowadays, with the latest tech advancements, most electric bike batteries are made to last.

However, with everyday usage, even the best ones will get worn out over time to such an extent that you might need to consider replacing it.

Here are some of the top reasons why you will have to replace or repair your e-bike’s battery sooner or later:

1. You Aren’t Charging Your Electric Bike Battery Properly

When it comes to an electric bike battery, the way you charge it significantly determines your e-bike battery’s energy storage and its functional lifespan.

The rule of thumb here is that the day when you first get a new e-bike battery, make sure to charge it for straight 24 hours to clear any negative charge resting within your e-bike’s battery system.

Moreover, the same practice should also be followed if you end up storing your e-bike or go a month without using it.

According to our experience, an e-bike battery charges most efficiently between the ranges of 30% to 90%, whereas the last 10% and the first 30% are the most difficult for the battery to pick up.

Therefore, if you are an active e-bike user, it is highly recommended to plug in the charger as soon as the battery hits 30% and remove the charger once it hits 90%.

Likewise, charging your e-bike battery on high discharge should also be avoided. In other words, avoid spending a huge amount of battery power over a short distance in a short duration.

While it might temporarily help increase the electric bike battery’s acceleration levels, it has a negative impact on the battery’s lifespan.

Read Can You Pedal an Electric Bike With a Dead Battery?

2. Battery Capacity Degradation

Though the latest lithium-ion batteries have several advantages over the former nickel-based batteries, one problem common to all e-bike batteries is the deterioration of their lifespan.

In other words, with every full charge cycle, your electric bike battery loses part of its capacity. While the capacity loss may seem trivial, it eventually snowballs to hundreds and thousands of charge cycle’s.

E-bike batteries’ ratings are a measure of the number of charge cycles it takes to reduce the battery capacity to 80%.

While the number of charge cycles required to adversely impact an e-bike battery may vary, an electric bike typically requires 800 to 1000 full charge cycles to deplete its storage capacity.

This means that it will require approximately 1500 to 2000 charge cycles if you charge your e-bike battery from 50% to 100%.

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3. Your Battery Management System (BMS) Is Damaged or Broken

Regardless of the model or type, every electric bike battery comprises an in-built safety mechanism called BMS-Battery Management System.

Not only does it help in preventing your e-bike battery from overheating, but it is responsible for evenly distributing the charge when connected to a motor or charger.

The BMS also reduces the risk of blow-ups or fire by making sure that your e-bike battery doesn’t accidentally short or fry the motor or charger.

Moreover, in case your electric bike battery stops working for no apparent reason, even after having a low number of charging cycles, it means that the BMS has failed.

Therefore, to save the BMS from any future damage, make sure to store your battery in the right environment; there’s no heavy physical strain or stress applied to it. Most importantly, follow proper charging methods.

Read How Long Does a Battery Last on an Electric Bike?

4. You Probably Aren’t Storing Your E-Bike Battery Properly

Although made to work in all environmental conditions, extreme weather conditions have a direct impact on an e-bike battery’s overall capability and performance.

While it can be used in hot or cold temperatures, storing an electric bike battery in a boiling or frigid space can end up causing significant damage in a few hours.

Ideally, an electric bike battery should be stored in temperatures between 40-degrees and 90-degrees Fahrenheit.

Also, keep from storing your e-bike battery in the open air or damp environment conditions.

In case it gets wet, use a dry cloth to dry it well and wait for fifteen minutes before you plug it in to charge.

5. You Are Overcharging the Electric Car Battery

Overcharging your electric bike battery can result in its cell losing its voltage capacity and becoming dysfunctional.

What happens is that owing to the excessive supply of electric chargers, an e-bike battery’s voltage capacity gradually starts rising and surpasses the safety range, also known as max voltage.

In simpler words, the more time an e-bike battery spends plugged in with the charger, the higher is the probability of negative reactions being provoked inside the lithium cells.

how to repair electric bike battery
how to repair electric bike battery

Read When to Charge an Electric Bike

How to Repair Electric Bike Battery?

Now that you know the primary causes that can result in damaging your e-bike battery, it’s time for you to learn how to repair an electric bike battery.

Whether you are facing issues with your e-bike’s ignition or it isn’t working at all, follow the below mentioned steps to make your electric bike battery functional again:

Step 01 – Extracting the Battery Box:

Though the overall process is simple, it requires some accessories and tools. This includes; electric tape, an old or unused, and a wire cutter electric bike battery.

Once you have all the essential tools, start by opening the lithium-ion battery that you got from the repair shop.

While unscrewing it, ensure that you don’t cause damage to the fragile battery box found inside, as you will be using it later in the e-bike battery repair process.

Step 02 – Removing 6 Individual Battery Cells:

Carefully remove six individual battery cells connected in a 2-2 parallel format from the old lithium-based e-bike battery.

While doing this, make sure that you don’t cut or disconnect the parallel links between the cells. Only cut the series connection.

Read How Long Does a Battery Last on an Electric Bike?

Step 03 – Assess the Old Battery’s Voltage:

Once the cells are delinked, take out a multi-meter tool to analyze the old e-bike battery’s voltage. Note that batteries are in good condition if the reading is at 10.8 V or above.

On the other hand, if the reading shows any number below, it means that the cells are bad or dead. It is advised to repair the cells before moving forward in such conditions.

However, if the damaged cells are beyond repair, opt to buy new lithium cell replacements from an e-bike dealer rather than waste your time fixing the irreparable.

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Step 04 – Reconnect the Cells:

Next, carefully use a wire to connect the cells in a series format. Once all the cells are reconnected to each other- the old ones replaced by new use the multi-meter again to check the overall voltage. Ideally, it should be between 36V to 42V.

Step 05 – Open the Damaged E-Bike Battery:

Moving to the damaged e-bike battery, now open it and remove the dead cells. However, make sure that you don’t cause any external damage to the battery box and that you keep the circuit intact.

Read How to Ride an Electric Mountain Bike

Step 06 – Connecting the Circuit to the Battery Pack:

Now, strategically use some copper wire to connect the circuit (the one you fixed) with the battery pack. On opening the cells, you will see four loose wires radiating from the circuit.

Note that the longest wire has a negative charge out of all the four, while the remaining three comprise positive charges.

Step 07 – Enclosing the Circuit:

Before closing the e-bike battery’s circuit, keenly check it for any loose wires or open connections. In order to do this, you will have to carefully attach the circuit to your electric bike. Once done, push the power button to check if it’s working or not.

Don’t stress out if there’s no reaction even after the button has been pressed. Simply connect your electric bike battery with the charger for 5 to 10 minutes before trying to start it again. This procedure solves the problem in most cases.

Step 08 – Reattaching the Repaired Battery:

Last but not least, use adhesives such as super glue or tape to fix the circuit in your e-bike’s battery box. Note that the battery box should be fixed perfectly to prevent any further malfunctions.

Read 5 Ways to Charge Your electric Bikes in Remote Areas

E-Bike Battery | Maintenance and Safety Tips

Do you know why lithium batteries succeeded in replacing the old nickel-based ones? That was because lithium batteries can store significantly large amounts of energy and can last very long if taken care of.

Here are some tips and tricks on how to maintain a healthy e-bike battery life:

1. Keep the Lithium Battery Charged

In order to keep them in their optimum condition, it is essential to keep the lithium batteries fully charged, even after driving for a few miles.

As regularly draining the e-bike battery and discharging it will result in reducing its ability to store charges.

Therefore, ensure to recharge the lithium battery as soon as you get back home.

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2. Plan Long-Term Storage for Your E-Bike Batteries

If you are going out of town and know that you won’t be able to use your e-bike battery for the next few months, it’s wise to take extra precautions when setting up permanent storage.

This is important, primarily because the rate at which a lithium battery discharges is the lowest when it’s flat and highest when it’s full.

Therefore, it’s advised to store electric bike batteries in the open air and cold storage with an 80% charged battery.

However, if you aren’t going anywhere and just want to store your e-bike battery, remember to give it short charges every 4 to 6 weeks.

3. Keep the Electric Bike Battery Dry and Clean

Though designed to cope with riding in showers, there is still a little danger in operating or plug-in an electric bike battery that’s wet.

Therefore, after a ride in the rain, use a dry cloth to dry any and all connections and components of your e-bike to avoid corrosion and oxidation.

If not dried properly, the moisture can weaken the e-bike battery’s ability to power the bike.

4. Keep the Lithium Batteries Cool

Being left out in a warm environment can decrease the electric resistance of the lithium powder present inside the battery cells.

As a result of this, your e-bike battery will need to be charged more often and will discharge more quickly in warm conditions.

Comparatively, in a cold environment, your e-bike will travel less due to the same property of lithium powder- meaning that you will be able to travel more on warm days.

Therefore, it is advised to store your electric bike battery under cool temperature with a full charger for longevity.

However, always remember to warm the e-bike battery at room temperature before plugging it with the charger.

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Read Can You Ride an Electric Bike if Banned from Driving?

The Bottom Line

Electrical components are extremely sensitive. Therefore, they need to be dealt with utmost care and frequent maintenance.

If you are an e-bike owner, the best way to take care of it is by following the user’s manual and knowing how to repair an electric bike battery in your time of need.

Without proper maintenance or knowing how to repair electric bike battery at home, the cost of replacing an e-bike battery might end up burning a hole in your pocket. Save your money and time by fixing your electric bike battery at home!

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FAQs – Frequently Asked Questions

Q: How long does a repaired e-bike battery last?

A typical electric bike battery lasts for 2 to 4 years, depending on how well the battery is maintained and cared for. On the other hand the life of a repaired e-bike battery depends upon the type of battery, the severity of the damage that had to be repaired, and the quality of workmanship. On average, a repaired lithium battery can last for about 300 charges.

Q: Is it better to replace an e-bike battery or repair it?

Repairing an e-bike battery is relatively less expensive than purchasing a new one. Therefore, depending upon the extent of the damage, it’s best to refurbish the battery rather than investing in a new one.

Q: How much does a new e-bike battery cost?

A high-quality e-bike battery can cost somewhere between $500 to $900, depending on the capacity and brand.

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