How to test an electric bike battery?

The battery is one of the essential elements of any electric bicycle. Whether you have a lithium or lead-acid battery, it's equally important to regularly test and care for it. Just as with cell phones, computers and other battery-powered technology, the overall health of your battery can have a significant impact on the performance of the entire piece of equipment.

You are wondering how to test your electric bike's battery? There are several ways to check. We explain!

An indispensable tool: the multimeter

A multimeter is a small portable probe that measures voltage, current and resistance. A display on your device will show each reading. Although there are digital and analog multimeters, the former tend to get more accurate results.

How to test the battery of your electric bike 

Testing an electric bicycle battery is fairly simple. Once you have a good multimeter at your disposal, you can easily monitor the overall health of your battery. Just follow these 5 steps: 

  1. Connect the multimeter: the battery will need to be removed and charged to 100% for for this process, at least 6 to 8 hours. If your battery cannot be disconnected from your bike frame, check that it is securely in place. Insert the multimeter probes into the connector or port on the adapter. Be sure not to force or apply excessive pressure, as this could damage either unit.
  2. Test the battery charge: Most standard multimeters have an AC/DC readout function and a "battery test load" function. Set your multimeter to DC. It is generally not advisable to use AC, as this could overcharge your electric bike's battery. This reading will not only tell you the battery's ability to power up, but also the energy density needed to communicate with the motor and other features. As long as it hasn't deviated too far from its original number (which you can find in the owner's manual), it means your battery is still good.
  3. Test the voltage : by switching your multimeter to the volts function function, you can perform a voltage test. This is important because the performance of an electric bicycle is closely related to its voltage. Check the manual to find out what the voltage range is for your brand. If you have been charging it for several hours, your voltage should match the number in your manual. When your electric bike's battery drops below a specific voltage reading, it shuts down to prevent damage to the unit. Simply put, if the voltage is too low, it's a sign that the battery may be running down.

For example: 

A 52V electric bicycle battery should read approximately : 

58 to 42 V

A 36V battery, on the other hand, should show : 

36 to 28 V

Let's assume that the readings do not fall within these ranges. If this is the case, it indicates that the battery may be wearing out gradually. 

  1. Test the current: The next step is to test the current. This is the amount of energy and charge your electric bike battery can hold and the amount discharged per hour. This will allow you to examine its longevity. Compare the reading on the meter to your manual. If you find that you are running out of power too quickly during rides, you may have an over-discharged electric bike battery.
  2. Check the resistance: this is the final step. It is a key element in the performance of your electric bicycle. What is the resistance? It's what tries to stop the flow of electric current through the battery. It exists in all electrical circuits, but it should never be too high. should never be too high. Otherwise, it could cause overheating problems. Indeed, the higher it is, the lower the flow of electricity in the battery.

As you can see, testing an electric bicycle battery involves several steps. The overall health of your battery combines its charge, voltage, current and resistance. If all of these are where they should be, you can rest assured that it is still in good working order.

Batteries for EVs often have a warranty of 6 to 24 months. Bosch batteries, for example, are guaranteed for 2 years or 500 cycles, which corresponds to a full charge after a full discharge.  

Battery monitoring system 

In addition, most electric bikes have a built-in battery management integrated battery management system, also called a control console. With this system, you can have access to all the information about the battery status through a display. It can also display the time, speed or assistance mode.

It is very useful to evaluate the voltage and the current, as well as to protect the battery components from temperature from temperature and the impact of charging/discharging. So it keeps an eye on the condition of your battery and extends its life cycle.

Its only flaw is its size. It can take up too much space on the handlebars. 

That said, multimeters are still considered more accurate than battery monitoring systems. The latter have fewer features and can also be expensive. In addition, they are not universal. They differ in design, size, parts used, depending on the type of battery. 

To conclude

We recommend that you to invest in a multimeter when your electric bicycle battery is nearing the end of its life or is showing signs of weakness. This is the best way to check the condition of your battery! The control panel, which is usually sold with your EAB, will give you more superficial data. Otherwise, you can always go to a professional!

FAQ on the state of your electric bike's battery 

What are the signs of a faulty battery? 

The signs of a bad battery are usually easy to spot: a battery that overheats, doesn't hold a charge, or seems to have a weak connection to the engine. Signs that should alert you. 

How do I connect a multimeter to my battery type?  

You will usually find an adapter specifically designed for battery testing. Simply remove the case and insert the multimeter probes. 

What voltage should I look for on my multimeter? 

If you have a 36V battery, the ideal range your meter should read is between 28V and 36V. Adjust this factor according to the voltage of your electric bike. As a general rule, if your reading is 10 volts lower than your manual indicates, it is too low.