Why Do Ebike Batteries Die? (Does It Need Replacing?)

  • By: Kevinsmak
  • Date: September 21, 2022
  • Time to read: 6 min.
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Ebikes have come a long way in the last few years. The batteries have improved, the motors have gotten more powerful, and the overall design has improved.

However, one thing that hasn’t changed much is the lifespan of an ebike battery. If you’re an ebike rider, you know that your battery will eventually die. But what causes this, and is it something that needs to be replaced?

E-bike batteries die because they are not properly maintained. Battery capacity degradation, not charging the battery properly, and improper storage can also lead to the death of an ebike battery. The battery can also die because you regularly fully discharge the battery before charging it again.

Why Do Ebike Batteries Die?

Here are some of the main reasons why ebike batteries die:

Battery Capacity Degradation

Lithium-ion batteries have several performance benefits compared to nickel-based batteries that were once used. However, reducing the battery’s total lifespan is an issue affecting all batteries.

Your battery gradually loses a tiny portion of its total capacity after each full charge cycle. Although this minor amount of capacity loss is negligible, it mounts up after hundreds or thousands of full charge cycles.

Most electric bike batteries are rated for the number of charge cycles needed to lower their capacity to 80%. In other words, your battery will contain 20% less energy than the first time you used an eBike battery after you have fully discharged and recharged it a specific number of times.

Although the number of cycles needed to deteriorate a battery varies completely, it usually takes 800 to 1,000 full charge cycles. We also want to note that it’s a full charge cycle, something you’ll rarely do with your battery.

It can take 1,500–2,000 charge cycles if you recharge it from 50% to 100% before your battery is down to 80% capacity.

Improper Charging

The way you charge your battery also has an effect on its lifespan. You should always use the charger that came with your bike, as it matches your battery’s specific voltage and current needs.

Avoid overcharging or undercharging your battery. Overcharging can damage the cells, leading to a shorter lifespan.

Undercharging can also damage the cells and cause the battery to become unstable.

It’s best to charge your battery when it reaches about 20% capacity. This helps to prolong its lifespan.

You should also avoid storing your battery in extreme temperatures, as this can damage the cells.

Improper Storage

Storing your battery in extreme temperatures can also damage the cells. If you live in an area with very cold winters, it’s best to take your battery inside when it’s not used.

You should also avoid storing your battery in direct sunlight, which can cause the cells to degrade faster. It’s best to store your battery in a cool, dark place.

Regularly Fully Discharging the Battery

One of the worst things you can do for your battery is to regularly fully discharge it before recharging it. This can cause irreversible damage to the cells and shorten the lifespan of your battery.

It’s best to avoid fully discharging your battery. If you must discharge it completely, make sure to recharge it as soon as possible.

Damaged or Broken BMS

Every eBike battery has a battery management system (BMS), which performs several different functions. Due to the complex makeup of your eBike battery, the BMS helps in the battery’s safe and even charging or discharging power when it is linked to a charger or motor.

The BMS also minimizes the chance of a fire or explosion if your battery becomes damaged by ensuring that it doesn’t accidentally short out or fry your charger or motor. 

The BMS has probably failed if your battery suddenly stops functioning for no obvious reason despite having only a few charging cycles. You can prevent the BMS from being harmed by using the right charging procedures, keeping your battery in the appropriate conditions, and ensuring that it doesn’t experience much physical stress or strain.

The BMS can, however, occasionally just stop working for no apparent reason. Now is the time to get in touch with the e-bike or battery manufacturer to inquire if a replacement battery is covered under their warranty coverage.

How to Tell When an Ebike Better Needs Replacing

The most obvious sign that you need a new ebike battery is when the one you have stops holding a charge. If your bike only goes half as far as it used to on a single charge or takes twice as long to recharge, those could also be signs that the battery is losing capacity.

Other signs that you may need a new battery include:

Battery Swell or Leak

Sometimes, batteries can start to swell or leak, which is a sure sign that it needs to be replaced. If you notice any of these signs, it’s best to replace your battery as soon as possible.

A damaged or failed battery can cause serious problems for your ebike.

Strange Noises

Strange noises coming from the battery while it’s charging or in use can be caused by a number of things, including a damaged cell or loose connection. If you hear any strange noises coming from your battery, it’s best to take it to a certified ebike technician to have it checked out.

Ebike Won’t Turn On

If your ebike doesn’t turn on, it could be a sign of many different problems, including a dead battery. It’s best to take it to a certified ebike technician to have it checked out.

Tips To Prolong the Life of Your Bike Battery

Even if you take good care of your battery, it will eventually need to be replaced. However, there are some things you can do to prolong the life of your battery and get the most out of it.

Here are some tips:

Use a Higher-Quality Charger: Using a high-quality charger is one of the best ways to prolong the life of your battery.

Avoid Extreme Temperatures: Extreme hot and cold temperatures can damage your battery.

Store Your Battery Properly: Storing your battery properly is important to prolonging its life.

Regularly Check the Battery Connections: Making sure the connections between the battery and the bike are secure can help prevent damage to the battery.

Ebike Battery FAQs

How long do ebike batteries last?

The lifespan of an ebike battery depends on several factors, including how often it’s used, how well it’s cared for, and the quality of the battery. In general, ebike batteries last for 3-5years.

Should I charge my ebike battery after every ride?

No, you don’t need to charge your bike battery after every ride. However, it’s a good idea to charge it regularly to keep it in good condition.

Why won’t my ebike battery charge?

There are several reasons why your ebike battery might not be charging. It could be a problem with the battery, the charger, or the bike itself.

If you’re having trouble charging your battery, it’s best to take it to a certified ebike technician to have it checked out.

Final Thoughts

The ebike batteries can die because of battery capacity degradation, improper storage, or damage to the battery. If you think your ebike battery needs to be replaced, it’s best to take it to a certified ebike technician for help.

When going on long trips for days, you can always take a generator with you to charge the ebike.


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