Nothing frustrates an e-bike cyclist like a motor that keeps cutting out. I’ve been there, and I wouldn’t want to relive the experience. So, I understand when you ask, ‘why is my electric bike cutting out?’
While most e-bike motors cut out because of loose connections, especially on the prongs, motor, and throttle, others cut out due to failing batteries, sensors, controllers, or pedal-assist.
As you’ll later learn, even something simple like pressing the lever unintentionally or damaging it could result in a power cut out.
So, you have to diagnose the issue from different angles, and I’ll help you do that.
Not only that, I’ll share with you the relevant fixes to stop the cutting out and possibly prevent its recurrence.
Let’s get into it:
Why Is My Electric Bike Cutting Out? (8 Key Reasons)
Here are some possible explanations for why your e-bike’s power transmission is disrupted.
1. Your Electric Bike Keeps Cutting Out Because of Loose Connection
When speaking of loose connections, you’ve to check the following components:
a) The Prongs
If the prongs are loose or disconnected, the motor will misbehave. Often, the prongs disconnect when you hit a bump or ride over a rough surface.
If that’s the case, realign the prongs and then retest the motor. But if the motor cuts out the power wholly even after recharging the battery, check the charger.
If its indicator light is absent, the charger is faulty.
What else could be wrong with the prongs?
Other than loose prongs, also check out for signs of wearing or burning.
If the prongs are worn out or burned, there’ll be a power disruption, and the motor will intermittently cut out.
Overall, if the prongs are either worn out or burned, replace them. If you cannot do it, take your e-bike to a bike repair expert.
If the throttle is loose, there’ll be a disruption in the power transmission. Luckily, you can fix the issue by realigning the throttle.
What else could be wrong with the throttle?
Other than looking for a loose throttle, check for stickiness when you pull the throttle out. Additionally, look for signs of throttle damage.
If the throttle is sticky or damaged, consider replacing it.
c) Motor Connections
If there are connection issues with your motor, your motor will shut out intermittently.
First, look at the motor inhibitor (responsible for cutting off the wire transmission). If it’s not well engaged, fix it.
Also, look at the wires connecting the motor to the rear hub. If they are loose or just damaged, you’ll have a loose connection, and the motor will cut out.
Watch out for burned or even melted wires. Those are the signs of the motor overheating.
In most cases, replacing the motor is advisable to protect the controller.
Also, look out for missing or damaged motor connections. If anything is missing or damaged, there’ll be a power disruption.
2. Your Electric Bike Keeps Cutting Out Due to a Failing Component
Consider checking out the components below as their failure affects the power transmission system.
a) Dead Battery
Most e-bikes disconnect intermittently due to a dead battery. No matter how you charge it, if the battery is dead, it’ll fail the motor.
Sometimes, the battery’s management system shuts off to stop the battery from overheating or draining too fast. Overall, a considerable voltage drop only means one thing – the battery cells are bad.
So, consider reducing your e-bike’s battery load by dropping the pedal-assist level when ascending. If that doesn’t work, replace the battery (View on Amazon).
While at it, ensure you get a better quality replacement.
If you are not sure about the problem, find a bike similar to yours and use its battery. If the problem stops, then it’s evident your battery is dead and needs replacing.
b) Failing Controller
The controller is your e-bike’s processor. It picks signals from the sensors and bike controls, analyses them, and transfers power to the motor.
So, if the controller has an issue, power won’t get to the motor.
Look for loose or disconnected wires and fix them. And if that doesn’t work, check the power switch to ensure it’s turned on.
The other thing to check is the circuit breaker. If it’s burned, replace it.
c) Failing Pedal Assist
A pedal-assist typically gives you anything between 25-200% (in terms of power) when ascending. But if the pedal assist is failing, there will be an interruption in the motors power transmission.
Often, the pedal-assist fails due to these two reasons:
- Misaligned magnets
- Wrong mounting of the pedal-assist detector
In the case of misaligned magnets, you’ve to check if they are wobbling. If they are, push the disc closer to the bottom bracket sensor.
And if the pedal-assist detector is mounted far off the disc, flip your e-bike over and try adjusting the pedal-assist detector.
If the job is too technical for you, take your e-bike to a repair expert.
d) Failing Sensors
If there’s a problem with the sensors, the motor will cut out. Often, this issue is associated with loose cable connections.
At other times, however, issues like dirt and moisture could fail the sensors. Also, watch out for damaged sensors.
If the sensors are damaged, replace them and if they are clogged with dirt, clean them.
Don’t forget to check for moisture, however. If the sensors are wet, dry your e-bike correctly before riding.
3. Your Electric Bike Keeps Cutting Out Due to An Issue with the Brake Levers
Here are two questions to ask:
a) Are the brake levers broken?
If the brake levers are damaged, the inhibitor switch (a safety switch that cuts the motor power) becomes stuck.
Check the brake levers for damage. If they are broken, replace them. And if it’s the switch that’s broken, replace it. You can get the replacements from your local repair shop
b) Do you intentionally press the lever?
Sometimes, the problem could be as trivial as the unintentional pressing of the brake levers. Doing so disengages the motor and cuts out power.
Avoid pressing the lever when cycling.
1. Why Does My Electric Bike Keep Cutting Out?
Your electric bike could be cutting out because of a loose prong, motor, or throttle connection. It could also be that its battery is dead or a damaged brake lever.
Additionally, check for failing parts, such as sensors, pedal-assist, and controller.
2. How Long Do Electric Bicycles Last?
Most electric bikes perform at their very best for about 3-5 years. After that, the battery starts to die, and the motor becomes less efficient – unless you maintain it.
But with the proper maintenance, you can expect your battery to last you about 10,000 miles or more before you can replace it.
3. How Do I Know If My E-Bike Battery Is Bad?
Your e-bike battery is bad if it no longer holds some charge. You can know that by testing its current and voltage using a multimeter.
Just connect the multimeter to the battery and then read the value.
If your battery is rated 36V, for example, then the multimeter should indicate so.
4. Do Electric Bikes Charge When You Pedal?
Electric bikes only charge when you connect the battery to a power source. So, no, electric bikes don’t charge when you pedal.
5. Do Electric Bikes Have Fuses?
Most electric bikes have inbuilt fuses (or circuit breakers). Some even have two, one for the supply and the other for the charging circuit.
Generally, the fuse interrupts the electric circuit to protect your electric components from excessive current.
6. Why Does My Electric Bike Battery Die So Fast?
Most electric bike batteries die fast because of too much load. If you overcharge your battery, it wears out much quicker.
It’s also worth noting that electric bikes have lifespans. A standard lithium-ion e-bike battery lasts for 2-3 hours, enjoying 300-700 charging cycles.
If you’ve exceeded the charge cycle or the number of years, the chances are that the battery is dead.
7. Can You Overcharge A Bike Battery?
Overcharging your bike battery only invites problems. For one, the electrolyte might boil to damage other parts or burn you if it gets into contact with the skin.
The battery could also overheat and blow up.
So, do not overcharge the battery as you’ll kill it in one way or the other.
8. How Fast Do Electric Bikes Go Without Pedaling?
An e-bike with a 750W-1,000W motor can hit 20mph while you are not pedaling. That means you’ll go much faster if you pedal.
9. What Is The Best Electric Bike For The Money?
Here are the four best electric bikes for the money:
- SWAGTRON Swagcycle EB-5 – Best folding electric bike
- ANCHEER Electric Bike 350W – Best electric mountain bike
- Speedrid Electric Bike – Best electric fat bike
In conclusion, why is my electric bike cutting out?
Generally, you should check out for loose connections or faulty components related to the e-bike’s power transmission system. That’ll help you diagnose the reason behind the power cutout and fix it.