What are signs of a bad battery?

The signs of a bad battery are usually easy to spot. Batteries that overheat, do not hold a charge, or seem to have a weak connection to the motor, are all signals that maintenance may be in order.

How do I connect a multimeter to my type of battery?

On a soft pack battery, you will usually find an adapter specifically for battery testing. You will need to remove the casing and insert the multimeter prongs into the pins on the underside on a hardpack.

What voltage should I look for on my multimeter?

If you have a 36v battery, then the ideal range for your meter to indicate is between 28v and 36v. Adjust that factor for your particular e-bike voltage, but a rule of thumb is that if your reading is 10 volts below what your manual states, then it is too low.

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How to Test an eBike Battery

Written By:

Lawrence Bonk

Updated February 28, 2023

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Difficulty Easy

Steps 5

Time Required 10 minutes

Sections

Things to Know

To keep your high-end eBike in the best condition, you will need to know how to test the battery on an electric bicycle. Just like with phones, laptops, and any other battery-powered tech, the overall health of your electric battery can have a powerful impact on how the entire machine performs. Thankfully, performing that checkup is made much easier with the help of a multimeter.

Also, remember there are many factors that can affect the battery’s health. For instance, if you regularly go over the bike’s recommended weight limit, there will be more strain on your battery. We have a great article that expands on how rider weight can affect electric bikes so you can save some money on not needlessly replacing quickly worn-out batteries. And if saving money is important to you, check out how a folding electric bike can save money. Now you can keep reading to learn to use a multimeter to check your battery’s health.

Key Takeaways:

You will want to test your battery for load, voltage, current, and resistance.
Do not test on the AC setting, as this could damage the battery.
If voltage reads roughly ten volts under your overall ideal battery level, then your Bike Monitoring System may need attention.

What is a Multimeter?

A multimeter, also called a multitester, is a small handheld probe that measures voltage, current, and resistance. A screen on your device will display each readout. While digital and analog multimeters exist, the former tends to garner more accurate results.

How To Test Your Electric Bikes Battery

Testing an e-bike battery is fairly simple. Once you have a good multimeter at your disposal, you will be able to keep tabs on your overall battery health with ease. And, if you’re curious, then you’ll want to learn about an electric bike with 1000w torque.

STEP 1 Connect the Multimeter

The battery will need a full charge for this process– about 6 to 8 hours at least. If your battery pack cannot disconnect from your bicycle’s frame, make sure that the bike is steadied in place. Insert the multimeter into the connector or adapter port. Be sure not to force it or apply excess pressure, as this could damage either device.

STEP 2 Test Load Battery

Most standard multimeters have an AC/DC readout function and a ‘test load battery’ feature. Set your multimeter to DC. It is generally not advised to use AC, as it could overload your e-bike battery. This reading is not just the ability for the battery to turn on, but the energy density required to communicate with the motors and other applications of the entire bike.

STEP 3 Test the Voltage

Run your battery voltage test by switching the multimeter to the volts function. Consult with the manual to find what the voltage range is for your brand. If you’ve charged it for several hours, your voltage should match the listed figure in your manual. When your electric bike battery goes below a specific voltage reading, it will usually shut off to prevent damage to the device. That is when you’d receive a prompt to recharge. If the voltage is too low – usually ten or more volts below the figure listed in your manual- but the bike is still on, then the Bike Monitoring System may need attention.

STEP 4 Test the Current

Next, you’ll be testing the current. The current is how much energy and charges your e-bike battery can hold and the amount of power discharged per hour. You’ll be looking at the longevity of your battery life here. Compare the reading on the meter to that of your manual. If you find that you’ve been running out of power too quickly on rides, it could be that there is excess discharge from your e-bike’s battery.

STEP 5 Check the Resistance

Finally, test the resistance. Resistance is the amount of restriction a battery has and will directly impact the current. It should be the final setting on your meter. If you find your resistance is high, this could be the reason for overheating issues.

Related Posts:

STATS:

Some experts predict that e-bikes featuring lithium-ion batteries will account for about 60% of all e-bikes sold in 2023. (juicedbikes.com)
The ideal charging level for a battery is between 30% and 60%. (bosch-ebike.com)

Sources:

https://delfastbikes.com/blog/how-to-test-an-e-bike-battery

https://batteryuniversity.com/learn/article/rising_internal_resistance#:~:text=Measured%20in%20milliohms%20(m%CE%A9)%2C,less%20restriction%20the%20pack%20encounters.&text=Low%20resistance%2C%20delivers%20high%20current,on%20load%3B%20battery%20heats%20up.

http://physics.bu.edu/py106/notes/Ohm.html#:~:text=The%20voltage%20of%20a%20battery,is%20known%20as%20a%20current.

https://support.juicedbikes.com/hc/en-us/articles/360013334251-Checking-your-Battery-Voltage-with-a-multimeter

https://web.ua.es/docivis/magnet/multimeter.html

Lawrence Bonk

Lawrence Bonk is a copywriter with a decade of experience in the tech space, with columns appearing in Engadget, Huffington Post and CBS, among others. He has a cat named Cinnamon.