Battery Equivalents and Replacements

How to Charge Electric Scooter Battery Without the Charger

Charging an electric scooter battery without the original charger requires caution. Using an incorrect charger or method can result in damage to the battery or scooter and can even pose a fire risk.

If you've lost the original charger, the best course of action is to purchase a replacement charger specifically designed for your scooter's battery.

Published: September 1, 2023.

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Rechargeable Lithium Batteries

Lithium batteries that power electric scooters may be Lithium-Ion batteries with a nominal voltage of 3.6-3.7V and a maximum charging voltage of ~4.2V per cell, or they can be Lithium Iron Phosphate (LiFePO4) batteries with a nominal voltage of 3.2V and a maximum charging voltage of ~3.7V per cell.

Lithium-ion batteries also feature several similar, but nonetheless different chemistries, each having slightly different discharging and charging features.

Regardless of the exact chemistry type, rechargeable lithium batteries should NOT be overcharged, over-discharged, overheat, or anything similar - they are sensitive batteries, able to store plenty of energy, but also prone to overheating, catching fire, and even exploding.

How to Charge Electric Scooter Battery Without the Charger Quick Answer: Don't charge your lithium battery without having a proper/original charger - plain and simple.

If you're determined to charge your scooter without the original charger, whatever you do, it is your own responsibility. Here's a general approach:

Determine the Battery's Specification

Check the battery's voltage and current requirements. Most electric scooter batteries are 24V, 36V, or 48V.

Find an Alternative Charger

The charger must match the voltage and current requirements of the battery. For instance, if you have a 36V battery, you need a 36V charger.

However, check the charging end voltage since it depends on the exact battery chemistry - never charge the battery to a voltage that is higher than its charging end voltage.

Check the polarity of the charger to ensure it matches that of the battery. Wrong polarity will damage the battery.


Turn off the scooter.

Note: If applicable, remove the battery from the scooter and place/charge it in a fire/explosion-proof bag. If the battery catches fire, it is better to lose just the battery and not the scooter or something else ... seriously!

Connect the charger to the battery. Ensure the terminals are connected properly: positive (red) to positive and negative (black) to negative.

Plug the charger into the wall socket and turn it on.

Keep an eye on the battery to ensure it's not overheating. If it gets too hot to the touch, unplug it immediately.


You should not leave the battery unattended while charging.

Overcharging can damage the battery, so ensure the charger has an auto-cutoff or monitor the charging time and voltage yourself.

Using a multimeter can help in checking the voltage level of the battery.

Disconnect and Check

Once charged, disconnect the charger from the mains and then from the battery.

Check the battery voltage with a multimeter to ensure it's fully charged.


Always wear protective gloves when handling and connecting batteries.

Ensure the charging environment is well-ventilated.

If the battery has any visible damage, swelling, or leakage, do not attempt to charge it. Dispose of it following proper procedures.

Remember, it's essential to ensure that the charger you use is compatible with the scooter battery's voltage and current requirements. Using an incompatible charger can result in permanent damage to the battery, reduce its lifespan, or even cause a fire.

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How To Charge Electric Scooter Battery Using Variable Power Supply?

Charging an electric scooter battery using a variable power supply can be a useful method, especially when the original charger is not available.

However, as always, caution is paramount to ensure you do not damage the battery or pose a risk of fire.

Here's a step-by-step guide on how to charge an electric scooter battery using a variable power supply:

Determine the Battery's Specifications

Identify the battery's nominal voltage (commonly 24V, 36V, or 48V) and its full charge (end charging) voltage.

Know the recommended charging current. This can often be found in the battery's specifications.

Note: If you don't know what is the recommended charging current for your battery, go for 20% of the battery's nominal capacity - if the battery's capacity is 15Ah, charge it with no more than 3 Amps.

Setup the Variable Power Supply

Ensure the power supply output is turned off.

Set the voltage on the variable power supply to match the battery's full charge voltage.

Adjust the current setting on the power supply to match the recommended charging current of the battery.

Again, if you're unsure, start with a lower current setting; it will take longer but is safer.


Ensure the scooter is turned off. If possible, remove the battery from the scooter and charge it in a dry and cool area, preferably using fire/explosion-proof bag.

Connect the positive (red) terminal of the power supply to the positive terminal of the battery.

Connect the negative (black) terminal of the power supply to the negative terminal of the battery.

Make sure connections are secure and not touching any other metal parts to prevent short circuits.

Start Charging

Turn on the power supply.

Monitor the current and voltage readouts. As the battery charges, the current should gradually decrease. Once it gets very low, the battery is almost fully charged.

If the battery becomes excessively warm or swollen, turn off the power supply immediately. These can be signs of potential problems.


Regularly check the voltage and current of the battery using the readout on the variable power supply or with a multimeter. When the battery reaches its full charge voltage, it's fully charged.

Ensure you don't overcharge the battery. It's critical to monitor the charging process continuously.


Once the battery is fully charged, turn off the power supply output and disconnect the cables.

Safety Precautions

Always use the power supply in a well-ventilated area, and wear protective gloves when handling and connecting batteries.

Also, keep the battery away from flammable materials during charging.

Using a variable power supply can be a practical way to charge an electric scooter battery in a pinch.

However, always be aware of the risks and ensure that you're using appropriate settings to match the battery's requirements. If unsure, consult the battery or scooter manufacturer's guidelines.

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How NOT to Charge Electric Scooter Battery

If you Google how to charge an electric scooter battery without a battery charger, you may find advices that are very hazardous and may easily lead to battery overheating and even catching fire.

Some of these methods include:

How to Charge an Electric Scooter with a Portable Car Jumper

This is one of the craziest options, ideal to destroy the battery.

Portable car jumpers operate at ~12V and are far from being compatible with 24V, 36V, and 48V electric scooter batteries.

Also, portable car jumpers usually feature batteries in the 10-20Ah range but with a nominal voltage of 3.7V, which is increased to 12V via built-in DC-to-DC converters.

According to the Ohm's Law, an average 10Ah 48V battery stores 480Wh of energy, while a 15Ah 3.7V battery stores ~55Wh of energy - even if you could successfully transfer all the energy from this portable car jump starter to the battery in this example, the battery would be charged only to ~10%.

However, in theory, a 24V portable car jumper may be used to charge, for example, a 20Ah 24V electric scooter battery, right?

Well, a 20Ah lithium battery can be recharged with ~4 Amps, while jump starters are designed to provide hundreds of Amps - far from safe.

Note: Some portable car jump starters feature USB charging ports, and some electric scooter batteries feature USB ports for charging other devices, but which can be used to recharge the battery as well - only in this case, one can use portable car jump starter to recharge the electric scooter battery. It will take some time, but ...

How to Charge Electric Scooter with an Industrial/Power Tool Battery

If You have an empty electric scooter battery and a fully charged power tool battery that features the same nominal and charging voltage, in theory, you can connect the empty electric scooter battery and power tool battery with thick enough cables and transfer some of the energy.

This method is hazardous for several reasons since the user can't control charging voltage, charging current, and other important charging parameters.

Also, one would need several average power tool batteries (for example, 5Ah 40V - for marketing purposes, power tools' manufacturers often use end charging voltage as part of the tools' labels) to charge a single electric scooter battery (for example, 15Ah 36V).

If the batteries or wires start to overheat, stop charging.

In short, please don't do it.

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Long Story Short: There are several more methods for charging electric scooter batteries without chargers, but they are so dangerous that we don't want to include them in this article.

Once again - the only proper method of charging an electric scooter battery is by using the battery charger that is recommended by the battery's manufacturer.

If your battery charger is dead, order a new one, and with fast shipping, you will probably have it in 24-72 hours - be patient, wait for the OEM charger, and don't risk your battery by charging it using alternative methods!

Don't trust me? Well, go to YouTube and search for "electric scooter battery fire/explosion" - it happens more often than some people/companies want to admit!

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