Electric bike batteries can need to be revived if they have been deeply discharged or if they have not been used for a long period of time.

Reviving an electric bike battery depends on several factors such as the age of the battery, how often you use it, and how deeply it has discharged. However, here are some general tips that may help:

Charge the Battery Fully

To revive a deeply discharged e-bike battery, it is recommended to charge the battery fully using the manufacturer's recommended charger. Make sure the charger is compatible with your battery and that the charging time is sufficient. Typically, it takes several hours to fully charge an e-bike battery.

Check for Damage

It is important to check for damage when attempting to revive an e-bike battery. If the battery is damaged, attempting to revive it could be dangerous and may not be successful.

To check for damage, inspect the battery for any signs of physical damage, such as dents, cracks, or bulges. If the battery casing is damaged, the battery may be leaking or may have exposed electrical components. In this case, it is important to avoid handling the battery and to dispose of it properly according to local regulations.

You should also check the battery's connectors and wiring to ensure they are not damaged or corroded. If the connectors or wiring are damaged, it may be necessary to replace them or to have a qualified technician repair them.

Use a Desulfation Charger

Using a desulfation charger can help revive an e-bike battery that has been deeply discharged or that is not holding a charge. A desulfation charger sends high-frequency pulses to the battery to break up any sulfate crystals that may have formed on the battery plates. This process can help restore the battery's capacity and improve its performance.

It is important to note that desulfation chargers are not a guaranteed solution for reviving e-bike batteries, and may not work for all battery types or conditions. Additionally, it is important to follow the manufacturer's instructions carefully and to avoid overcharging or overheating the battery, as this can be dangerous and may cause further damage.

Charge and discharge the battery

Charging and discharging the battery can sometimes help revive an e-bike battery that has been deeply discharged or that is not holding a charge. This method is also known as "cycling" the battery and involves fully charging the battery and then discharging it to a certain level before charging it again.

To cycle your e-bike battery, follow these steps:

• Charge the battery fully using the manufacturer's recommended charger. Make sure the charger is compatible with your battery and that the charging time is sufficient.
• Use your e-bike until the battery discharges to a certain level, usually around 20-30% remaining charge. This will vary depending on the battery and the e-bike model.
• Charge the battery fully again using the manufacturer's recommended charger.
• Repeat steps 2 and 3 for several cycles, until the battery's performance improves.

Cycling the battery can help break up any sulfate crystals that may have formed on the battery plates and improve the battery's capacity. However, this method may not work for all battery types or conditions.

Seek Professional Help

If none of the above methods work, you may need to seek professional help. Contact the manufacturer or a qualified electric bike technician to help you diagnose and repair the battery.  They will usually have a good idea of whether your battery is salvageable.

Sometimes You Are Out of Luck

Unfortunately, there are some cases where attempting to revive an e-bike battery may not be successful. If the battery is too damaged, has been discharged for an extended period of time, or has reached the end of its lifespan, reviving the battery may not be possible.

If you have tried all of the recommended methods for reviving your e-bike battery and it is still not performing as expected, it may be time to consider replacing the battery.