Electric Bike Repair: Sharing Repair Tips
How to repair an e-bike, how to inspect, analyze and maintain the basics of an e-bike, a professional knowledge distribution in one go.
The instrument display is normal, the motor does not rotate
Cause of issue：
1. Determination of brake handle damage
2. Judgment of damage to the speed control handle
3. Motor damage judgment
4. The controller is damaged
1. Unplug the brake lever socket (normally open brake lever). If the motor is running, the brake lever is faulty, and the brake lever should be replaced.
2. The 5V voltage of the handlebar source is normal, detect the signal voltage of the handlebar, turn the handlebar, the signal voltage should change from low to high at 0.8~4.2V. If the voltage does not change and is less than 1V, the handlebar is faulty or the handlebar wire is short-circuited. If the voltage is greater than 1V and the change is normal, check the motor Hall signal (yellow, green, blue lines). If the voltage of the three-phase Hall signal lines is all 5V and the contact is good, the motor Hall is damaged, and the motor or the motor Hall element should be replaced.
3. Detect the motor Hall signal line separately, and turn the motor slowly by hand. The voltage of each phase should vary between 0 and 5V. If the voltage does not change, the motor Hall is damaged, and the motor or motor Hall element should be replaced. If the voltage transformation of each phase is normal and the power supply is normal, the controller is damaged and the controller should be replaced. To learn more about electric vehicle technology, please pay attention to the ddcshj WeChat public account.
4. Use a multimeter to detect the voltage of the input terminal of the power supply of the controller. The voltage should be greater than 36V (the battery is fully charged). If there is no voltage, the input line should be checked. Check the power supply voltage of the controller handlebar (connect the red and black wires of the handlebar), the normal voltage is 5~6V, if there is no 5V voltage, unplug the handlebar socket and the voltage returns to 5V, it may be a short circuit of the motor Hall element, such as If there is still no 5V voltage, the controller is faulty and the controller should be replaced.
5. First check whether there is a short circuit at the beginning of the speed control handle and the motor hall. Generally, it is more likely to cause a short circuit of the joint after rain and moisture. Therefore, pay attention to the waterproof of the joint of the handle. If the controller is damaged, check the switch before replacing the new controller. Are the switch and the motor hall switch shorted? Otherwise, it will cause continuous damage to the replacement controller!
6. If the motor does not rotate, focus on checking the motor Hall switch and the signal of the handle. If the controller is very hot when the power is turned on, it is generally because the power tube inside the controller is short-circuited, and the power should be cut off immediately.
Motor stops and turns
Cause of issue：
1. The battery voltage is in the critical state of undervoltage.
2. The battery connector is in poor contact.
3. The wire of the speed regulating handle should be broken.
4. The brake power-off switch is faulty.
5. The power lock is damaged and the contact is poor.
6. The line connector is poorly connected.
7. The components in the controller are not welded firmly.
8. The carbon brushes and the wire set in the motor have virtual welding.
1. Detect the battery voltage and recharge the battery.
2. Adjust or replace the plug.
3. Reconnect the lead of the speed control handle.
4. Adjust or replace the brake power-off switch.
5. Replace the power lock.
6. Re-plug the line.
7. Replace the controller.
8. Replace the motor.
The motor does not turn, and the instrument has no display
Cause of issue：
1. The fuse tube is burnt out.
2. The battery is damaged.
3. The battery wire is disconnected by virtual welding.
4. The power lock is broken.
5. The battery contacts or plugs are in poor contact.
Use a multimeter to detect the output voltage of the battery. If there is no voltage, check whether the fuse tube and fuse holder, the battery and the battery connection line are open. If the voltage at the battery output terminal is normal, check the voltage at the input terminal of the controller power supply. If there is no voltage , check whether the electric door lock and cable are disconnected or poorly connected.
Motor speed is slow
Cause of issue：
1. The speed control handle is damaged
2. The battery capacity is insufficient or cannot be charged.
3. The controller is faulty.
4. The motor is faulty.
1. Detect the voltage of the signal line (green line) of the speed control hand-holding speed control signal. When the handlebar is at the maximum angle, the voltage of the speed control terminal should be 4.2V. If it is less than this voltage, the speed of the electrode will be slow, and the speed control handle should be replaced. To learn more about electric vehicle technology, please pay attention to the ddcshj WeChat public account.
2. Recharge the battery.
3. Replace the controller or motor.
Motor Jitter (Brushless)
Cause of issue：
1. The motor Hall connector is defective.
2. The handlebars are in poor contact.
3. The speed signal line has interference.
1. The motor Hall connector is bad, reconnect it.
2. If the contact of the handle is poor, reconnect it.
3. There is interference in the speed signal line, try to replace the controller and instrument.
4. The vibration of the electric bicycle during use is generally caused by poor contact between the motor Hall switch connector and the handle connector. Therefore, focus on checking the connectors, especially the motor Hall switch connectors.
The motor is noisy
Cause of issue:
1. The bearing clearance in the motor is large.
2. Motor rotor sweep.
3. The magnets are loose and fall off.
4. There is axial movement inside the motor.
5. The surface of the brush motor commutator is oxidized, ablated, oily, uneven, and the commutator piece is loose.
6.The carbon brush holder is loose and the carbon brush holder is not correct.
1. Replace the bearing.
2. Re-repair the stator and rotor.
3. Re-bond the magnet.
4. Add a suitable washer in the axial direction.
5. Clean the surface layer of the commutator or weld the commutator piece firmly.
6. Adjust the carbon brush holder.
The power wheel turns, and the increment speed is very fast
Cause of issue:
1. The speed control handle is damaged or the ground wire (black wire) is open circuit or the plug-in is defective.
2. Controller failure (with brush)
1. Disconnect the speed control handle. If it is normal, the controller is normal. Check the speed control handle and ground wire. If the car still doesn't stop after disconnecting the speed control, the controller is damaged, and the controller should be replaced.
2. If the wheel turns when the power is turned on, the increment speed is very fast, most of which are caused by the poor contact of the ground wire of the turning handle. Therefore, focus on checking the grounding of the handlebar.
The instrument panel has no power display, and the motor is running normally
Cause of issue:
1. There is no voltage between the positive and negative leads of the instrument, and the wires or connectors are short-circuited.
2. The instrument is damaged.
Use the multimeter DC 50V gear to detect the positive and negative voltage of the instrument. If the voltage is normal, the meter is damaged. If there is no voltage, the wire or connector is disconnected, check the cable and connector.
The voltage display of the instrument is normal, the speed display is abnormal, and the motor is running normally
Cause of issue:
1. The instrument is damaged.
2. The speed signal line (black/white) is short-circuited.
3. The controller has no speed display.
1. With brush and 48V brushless: use the multimeter to detect the speed signal line and the positive pole of the power supply (48V brushless detection speed signal and negative pole) with the motor running speed, the voltage changes from low to high (36V models have 0 ～36V change, 48V brush has 0～48V change, 48V brushless has 0～25V change).
If there is no change, check whether the speed signal line is properly connected? Is there a short circuit?
If the voltage change is normal, it is a fault of the instrument. If the speed display is low, use a screwdriver to adjust the speed adjustment potentiometer on the instrument panel until it is normal.
2.36V brushless: first check whether there is a short circuit between the speed line (black/white) of the instrument panel and the controller. If it is normal, connect the controller speed signal line and the motor Hall line (thin yellow, green, blue) any phase line.
If the speed is normal, the controller is damaged; if there is still no display, the small instrument is damaged.
Loudspeaker out of control
Cause of issue:
1. The speaker is damaged.
2. The horn switch is damaged.
3. The connecting wire or connector is short-circuited.
1. After pressing the horn switch, use a multimeter to check the voltage at both ends of the horn connection. If the voltage is normal, the horn is damaged. If there is no voltage, the horn switch is damaged or the wire is open. Short-circuit the two wires of the horn switch to quickly find the fault point.
2. If the positive and negative poles of the electronic speaker are reversely connected, the speaker will be silent.
Cause of issue:
1. The light bulb is broken.
2. The headlight switch is broken.
3. The wires or connectors are short-circuited.
The repair method is the same as that of repairing the horn.
Continuously burn out the fuse
Cause of issue:
1. The controller is damaged.
2. The instrument is short-circuited.
3. The lamp holder is short-circuited.
4. Short circuit after the cable is damaged.
5. The positive and negative poles of the battery are reversed (after replacing the battery or using another brand battery box).
Unplug the battery, turn on the electric switch, and turn off all light switches. Use a multimeter to measure the resistance between the plugs (simple car contacts). If the resistance is very small, close to 0Ω, it means that there is a short circuit in the line, which can be detected by the open circuit method. If the power supply connector of the controller is unplugged and the display returns to normal, the controller is damaged. If it is still not normal, the instrument can be unplugged and tested, and so on. If the headlight or turn signal switch is turned on and the fuse is burned out, check whether the headlight socket or turn signal socket is short-circuited.
Insufficient mileage on a single battery charge
"Continued mileage" is based on the full charge of the new battery, the rider's weight is 75kg, the ambient temperature is (25±5℃), the wind speed is not greater than 3m/s, and the rider rides on a flat secondary road until the battery voltage is reached. Less than 10.5V to be powered off, the ride and mileage obtained under the above conditions.
There are many factors that affect the mileage continuation:
1. If the battery is old or new, the actual "continuous mileage" of a brand new battery may exceed 50Km, while the "continuous mileage" of a battery that has been used for a period of time will decrease, mainly due to the battery capacity decreases with time.
2. The actual load weight and other factors such as whether the road surface is flat, whether there is uphill and downhill, wind speed, wind direction, braking during driving, the number of starts, whether the tires are sufficiently inflated and the correct charging method, the temperature of the use environment and other comprehensive factors will affect the actual situation. The length of the "continuation mileage" (at a standard temperature of 25°C, the continuation mileage will be shortened by about 0.5km for every 1°C drop).
Quickly find faults and troubleshooting methods for electric bicycles
One car does not turn (that is, the motor does not turn)
(When there is electricity, turn on the power lock) Use a multimeter to measure the voltage of the motor leads, and immediately determine the fault between the controller and the motor leads or the control circuit
1. If there is a voltage in the measurement result, it is concluded that the motor is broken or there is an open circuit fault between the controller and the motor lead, which should be eliminated.
2. If the measurement result has the element voltage, it is concluded that the controller circuit is faulty, and the next step should be checked.
Measurement method: Disconnect the brake power-off plug of the controller, and then transfer the adjustment handle
1. If the car rotates, it is concluded that the brake power-off switch is broken, causing a short circuit fault, and the brake power-off switch should be replaced
2. If the car does not turn, replace the original speed control handle with a good speed control handle for the test. If the car rotates, it is concluded that the original adjustment handle is broken, causing the motor to not rotate, and a new handle should be replaced.
3. If the motor still does not move with the new speed control handle, it is concluded that the controller is broken and a new controller should be used
Measure the contacts of the battery box, you can immediately judge the failure caused by the power supply part that does not turn
1. If there is no voltage display, turn on the power lock, and the indicator light of the instrument panel does not light up, it is concluded that
a, the fuse tube fuse is broken
b. The wire falls off and the welding head is broken
2. If there is a voltage display, turn on the power lock, and the instrument panel display light does not light up, it is concluded that the power lock is broken and no power is supplied, and a new lock should be used to open the power lock, the car keeps turning and cannot be braked (car shock phenomenon )
Inspection method: Disconnect the controller from the plug of the speed control handle (three-wire plugs 7, 8, 9), and the fault of the speed control handle or the controller can be immediately determined.
1. After disconnecting the plug of the speed control handle, turn on the power supply to lock the car and it does not turn, then it is concluded that the speed control handle is damaged and should be replaced with a new one; if the photosensitive film or magnetic steel sheet falls off, it should be re-installed or pasted
2. After disconnecting the plug of the speed control handle, if the power lock is turned on and the car still does not turn, then it is concluded that the controller is broken, and the power lock should be replaced, but the power lock cannot be turned on or the fuse of the battery box will not be blown when it is turned on. Check method: disconnect the controller The power plug can immediately determine the fault. ① After disconnecting the power plug, open the power lock. If the fuse is blown, it is concluded that:
a, most of the short circuit;
b. The speaker part is short-circuited;
c. Short circuit in the power lock;
d. There is a short circuit in the instrument panel, which should be eliminated. ② Connect the battery plug first, then disconnect the opposite corner plug, and open the power lock. If the fuse is no longer blown, it is concluded that the motor is faulty. It should be checked and repaired or replaced in a targeted manner. ③ If the fuse is still burned after operating according to methods ① and ②, it is concluded that the controller is faulty and the controller should be replaced. ④ Another situation is that the fuse tube model is not properly selected, allowing If the current is less than the required value (the fuse is too thin), it cannot withstand the current of the electric bicycle, and the 20A fuse should be selected with a slow speed (low motor speed)
1. For the photoelectric speed control handle, open the handle and take out the photosensitive film. If the motor resumes operation and is normal, it can be concluded that the photosensitive film is too dirty, which affects the light transmittance and causes the vehicle speed to slow down. It should be cleaned or replaced with a new photosensitive film (at the same time, the light-emitting device should be cleaned once)
2. Use the multimeter DC voltage block to measure the controller power supply voltage and motor lead voltage, turn the speed control handle, the voltage change should be below 1V, if the change exceeds 1V, it is concluded: the controller is faulty and should be replaced
3. When the motor rotates, there is no abnormal noise, or the motor casing is overheated during operation (touching the hand is hot), then it is concluded that the motor is faulty and should be repaired or replaced
4. The battery voltage is too low, and the no-load voltage is lower than 36V. In the running state, it will be close to the undervoltage state, the motor car is small, the speed is slow, and there is no energy. The reason is the battery. The possible reasons are:
a. If the running mileage is too long and the electric energy is used up, it should be charged in time;
b. After the battery is fully charged, if one trip is less than 12.5Km, it means that the battery life is terminated and the battery should be replaced.
5. The charger is faulty, the battery is not fully charged, but it is mistakenly thought that it is sufficient, resulting in the speed of the vehicle being too slow and lack of energy. It should be repaired or replaced in time so that the battery can be charged as soon as possible
6. It is not ruled out that the motor itself has design problems and problems in manufacturing. The only way to solve it is to replace a qualified motor.
Electric bike catches fire:
Cause of issue:
1. Fire when charging;
2. Catching fire while riding.
1. When charging, remove sundries and inflammables and place them on the car, which will cause heat to ignite. Check whether the charging position is loose, causing the line to be short-circuited and ignited.
2. Fire when riding: generally divided into battery fire and controller fire. The fire in the battery part is generally caused by the loose part of the battery connection line or the short circuit of the bumpy friction line. The fire in the controller is generally caused by the loose connection of the phase line. Pay attention to regular inspections.
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