Battery FAQs


The battery does not work at all

Some batteries need to be turned on before use. 

I5 – the latest series of NCM Moscow (push button level indicator)

R3S – NCM Munich/NCM Hamburg (Toggle switch on the bottom of the battery)

D5 – NCM Prague (push button on the side of the battery)    

- The battery must be correctly seated in the battery rail.  The battery poles must be in contact with the battery seat and the battery must be locked to avoid sparks and connection problems.    All batteries with on-switch must be turned off before removing them from the battery rail!    

- It is not allowed to open the battery case. If the battery is turned on and there is no connectivity problem obvious, make sure to replace the battery.


The battery can’t be charged

- The indicator on the charger turns green right after connecting it to the battery. It won’t turn red, but the battery is empty.  The indicator on the charger turns green if the battery is fully charged, if there is a problem concerning the charging fuse or if the battery is deeply discharged.  - Try an alternative socket.  - Replace charger - Check charging fuse. For most batteries it is possible to reach the charging fuse from the outside of the battery case. (B1U, I5-36V. R3S). If the battery does not have a cover with the inscription "FUSE" (e.g. I5-48Volt), the battery must be sent in and replaced, as an internal charge fuse can only be changed by qualified personnel.

Attention! Never ask the customer to open the battery case!   

- The charger shows neither green nor red.  There is a high probability that the charger is defective. Try an alternative socket outlet, otherwise replace the charger.  - The LED of the charger blinks. There is a high probability that the charger is defective. Try an alternative socket outlet, otherwise replace the charger.  - The charger must have the correct voltage for the battery to be charged.   Inscription on the back of the charger:   36V - 42V Charger 48V - 54V charger

Do I need to “break-in” my batteries?

Yes, the batteries used in our eBikes will need to have a “break-in” cycle consisting of ~ three discharge/charge cycles before they will reach optimum performance. This involves three complete discharges and three complete recharges. After this initial “break-in” cycle the batteries will have maximum possible performance and less line voltage fluctuations under load.

How long does it take to charge a discharged battery?

Depending on battery capacity and charger output, batteries will typically take anywhere from 4 to 8 hours to charge. Li-Ion batteries take 70% of their charge in the first 1-2 hours.



- Sparks fly when the charger is connected to the battery. Observe the correct connection sequence: Connect charging socket to battery ⇒ plug mains plug into socket // disconnect mains plug from socket ⇒ remove charging cable.   If sparks are still flying, the charger should be replaced.  - The charger becomes very hot during charging. Heating up to 60 °C is normal.


The battery rattles in the holder or does not hold properly

- The battery contacts are bent or crushed. Repair is not possible without opening the battery housing. Return battery and replace if necessary. The case must not be opened by customers under any circumstances!  

- The contact pins on the NCM Munich / NCM Hamburg are bent / crooked. (Luggage carrier, not on the battery itself). The contacts on the battery holder can be carefully bent straight again.   

- The battery rail of the B1U battery (NCM Paris/NCM London) can be fine-tuned if necessary (screws). If the battery rattles while driving or the bolt of the battery lock does not engage.


General problems

- The battery heats up and smells charred. There seems to be a chemical reaction going on inside the battery. Do not continue to use the battery and store it outside the house. Never try to extinguish with water but use sand or other fire retardant and call the fire brigade. Replace the battery as necessary.  

- The battery case is torn / damaged.  Moisture penetration cannot be entirely precluded, and damage to the cells by falling or impact is also possible. Do not continue to use the battery and store it outside the house. Replace the battery as required.  

- The battery contacts are no longer shiny and are corroded. The contacts can be cleaned with a soft cloth.


General information about accumulators

BMS (Battery Management System)  
The battery is equipped with a BMS. This regulates the charging and discharging phases (including balancing of the interconnected individual cells) and protects the battery from overvoltage and under voltage.   

Charging/discharging cycles  
The specified charging cycles are not the same as the number of charging cycles. If, for example, the battery is charged twice with 50% charge, this corresponds to only one charge cycle.

Important! Charge your battery fully before using it for the first time and use it until there is only a remaining capacity of approx. 10%.   Discharge   Generally, a Li-Ion battery should never be completely discharged. Otherwise, there is a risk of deep discharge, which can irreversibly damage the battery. It is therefore advisable never to discharge the battery completely, despite BMS, which could switch off too late due to different external influences (temperature, age of the cells, defective cells due to external influences, etc.).   

Correct storage  
If you do not use the battery for an extended period of time, store it in a cool, dry place. The battery should be charged to approximately 45-60% during storage and connected to the charger for one hour every 6 weeks.


Which criteria influence the battery range?

Battery range is influenced by several factors, including battery capacity and motor efficiency. The battery management system (BMS) also plays a decisive role. Attention: With the same battery capacity, but different motors, the range can vary considerably. As so often, it depends on the individual case.    Also factors that influence the range: Road travel (underground / gradient), temperature, headwind, driver weight, payload


How much does a battery charge cost?

In basic terms, the cost of charging a battery depends on the price of electricity and the capacity of the battery. This usually amounts to approx. 0.3 to 0.8 kWh. The costs for a battery charge would be 8 to 20 cents with an electricity price of 26 cents/kWh.


How do I calculate the watt-hours?

There is a simple calculation method for determining the watt-hours of a battery. All you have to do is multiply the voltage in volts (V) by the ampere-hours (Ah). 


 Does the temperature affect the battery performance?

A rechargeable battery can deliver its optimum performance at temperatures between 10° and 25°. During cold and very high temperatures, performance can decrease significantly. In the winter season a reduced range is normal.


Storage of the battery during a longer period of inactivity

In the best case the bike should be stored dry and clean. Temperatures are unproblematic for the bike.    There are several factors to consider with the battery:   
- Storage dry at room to cellar temperature  
- Storage at a filling level of approx. 60%. 
- Check filling level regularly to avoid deep discharge.


General FAQs

What maintenance do eBikes need?

 eBikes can be ridden in pretty much the same conditions as a regular bike. They are fine in the rain or snow but shouldn’t be ridden underwater. The batteries should not be stored in extreme temperatures and if inactive, the batteries should be charged up (to top off their energy level) every 90 days


The screws / spokes on the wheel rust

- Please ensure to keep the bike under cover and out of the weather when not in use and refrain from leaving moisture on the E bike and coming into contact with the electrical components.  Claims as a result from water damage are not covered by the warranty.


The rim is completely cracked, or spokes are broken

If a rim is cracked it may be possible to have it professionally welded. Otherwise, replace the rim. We do not suggest riding a bike with the rim cracked. It is possible to ride a bike with a broken spoke in an emergency situation. Such as to get home. However, spokes are a structural part of the bike wheel and riding for excessive periods with a broken spoke will bend the rim causing the wheel to be permanently buckled. Spokes are replaceable. It is recommended to have a wheel trued by a professional wheel builder.


The pedals do not stay on the crank arms

Be sure to observe the marking on the pedals ("R" and "L" - left pedals have opposite threads). Reattach and tighten the pedals securely. Pedals are threaded in such a way the riding will tighten them, if this does not work it maybe due to wear in the pedal or crank arm threads.


The bicycle cracks when pedaling from the bottom bracket

If the cracking only occurs with motor assistance, an error in the motor is likely. If the cracking occurs exclusively without motor assistance, the bottom bracket is probably affected. This may be due to a loose bottom bracket or worn bearings.


The handlebar is loose when riding and is slack

There is a number of possible causes for loose handlebars: 
- The handlebars are loose at the connection to the stem. This will cause the handlebars to roll. Tighten the Allan head bolts on the stem 
-The stem is loose on the fork steerer tube. This will cause the stem to rotate around the fork tube. Tighten two Allan head bolts on the stem
-The headset is loose. This will cause the front of the bike to wobble and feel loose. Loosen the stem from the fork steerer tube and tighten down the cap at the top of the stem. This should clamp down the headset bearings and fix the problem. If this does not work it may be the headset is worn or incorrectly installed and will need replacing.


The driver touches the front wheel with his toes when he turns into a curve

This maybe normal depending on the specific model of bike. Bikes with a steeper headtube angle bring the wheel further back. It may be necessary to move your foot back on the pedal. The optimal riding position is with the ball of the foot directly over the pedal axle.


The suspension fork leaks oil

A light film of oil on the fork leg is normal as a part of lubrication. Excessive amounts of oil such as dripping down the fork leg indicate a work seal and will need to be replaced.


The frame is broken

This depends on the location and extent of the break. Minor cracks may be fixable with welding. For larger cracks the frame may need to be completely replaced. Depending on the cause and location of the break this may or may not be covered by warranty.


Do you have to insure an e-bike?

Pedelecs, i.e. e-bikes that reach speeds of up to 25 km/h, are legally regarded as bicycles and do not require insurance. These can sometimes be covered by household insurance. S-pedelecs, i.e. e-bikes that are capable of speeds of up to 45 km/h and autonomously driving e-bikes (e.g. with thumb gas), are considered motor vehicles and would therefore need to comply with standard road procedures depending on your state or territory


What to consider when transporting by car

Transporting an E-bike by car has a variety of considerations. If the bike is being transported inside the car it may be necessary to remove the wheels. On bikes with hydraulic brakes do not touch the brake leaver and insert a brake pad shim into the caliper to prevent the pads binding together and the brakes needing to be bled. It may also be necessary to turn the handlebars or remove mudguards and other accessories. If the bike is being carried on an external rack people bear in mind that an e-bike has electric components. High speed wind/rain whilst driving may cause water ingress on bearings and electric components. It is recommended to protect the electrical system from the elements where possible


Can the bike be driven in the rain?

Yes, all components are adequately protected against water ingress. However, you should avoid heavy rain, washing the bike with a pressure hose and water passages where the motor components are under water.


What is your address?

Prospect House 2 Sinderland Road, Broadheath, Altrincham, Cheshire, England, WA14 5ET


What is your phone number?

Due to the COVID, we currently only provide service through e-mail.

When will the item be back in stock?

The item will soon be back in stock. In the meantime, please push the 'notify me' button located directly underneath the product name to be notified as soon as we receive stock. To enquire for an expected arrival date for a specific model, please email support.uk@leoncycle.com.


Understanding (NCM) Speed and Power Settings

The system provides low to powerful support (depending on the selected setting) for the rider and also facilitates  mastery of gradients or riding in headwinds. However, it is assumed, that the system is adequately supported by the user. If the motor is overloaded in this respect, the system automatically switches itself off in order to protect  components from damage. To avoid this, use the e-bike like a bicycle without electrical Support for steep longer climbs.  

Example for a 7 gear shift: For steep climbs, select a maximum of support level 3 and shift them into a lower gear e.g. 2-3 and support the system. If tours with several gradients should be made, we recommend that you switch to ECO mode. In this way you avoid overloading the system and conserve the battery. You have 6 support levels 0-6 The following data are approximate guide values and can therefore vary slightly.  

0 = Motor does not support 
1 = 7-10 km/h 

2 = 10-13 km/h 

3 = 13-16 km/h 

4 = 16-19 km/h 

5 = 19-22 km/h 

6 = 22-25 km/h   

In stages 1-6 the motor only supports up to the specified speed. Achieving speeds beyond the assistance from the motor will require you to pedal.  

On the Display Unit there are 3 additional power settings, explanation of each is below:  

1. ECO = Saves battery capacity (higher range) --> Low power consumption = High range 

2. Normal = Average battery capacity --> Average power consumption = Average range 

3. Power = Lower battery capacity --> High power consumption = Short range


How to adjust/ set the correct saddle height.

The best and most simple method to set the correct saddle height, is to sit on the saddle with the crank arm in the 6 o'clock position pointing down. Place the heel of your foot across the center of the pedal axel. In this position the leg should be completely locked out and extended as much as possible. With this position, once the foot is slid back and the ball of the heel is on the pedal axle, there should be a slight bend in the knee at full extension.     Correct saddle height is very important to prevent injury and knee pain whilst cycling


I get knee pain whilst riding my bike, what could it be?

Firstly, please ensure that the saddle height on your bike is set correctly. Assuming the position on the bike is optimal, knee pain during cycling is often caused by iliotibial band syndrome. Whilst riding the quadriceps in the leg do significantly more work than the hamstrings. This caused the quadriceps muscle to strengthen and tighten. As a result of this tightening the illiotibial band can rub over the top of the knee causing inflammation and knee pain. The solution to this issue is regular stretching of the legs after riding and using a foam roller to help lengthen and relax the quadriceps and the illiotibial band


Can you straighten a buckled wheel?

Whilst is may be possible to true a wheel through tightening spokes if they are loose or incorrectly tensioned. It is not possible to completely straighten a buckled wheel. A straight wheel requires a perfectly circular rim, the spokes serve the purpose of both positioning the rim relative to the wheel hub and providing strength to the wheel through tension. If a wheel has been buckled due to hitting a curb or other damage, the rim is no longer circular. At this point tightening the spokes may no longer work, and rather than straightening the rim, a flat spot on the top of the rim is created through excessive tightening. It is important to regularly check the wheels for damage and check spoke tension. If a wheel sustains a serious buckle it will need to be completely replaced.


My bike no longer changes gears correctly or the chain jumps and changes gear. What is it, and how do I fix it?

Gear issues with bikes are very common. There are several factors which can cause gear issues however the fix is often relatively simple.    

Maintenance:     Pulling the gear lever moves a cable back and forth which allows the gear to change. Gear cables can often cause issues. The inner cable should be able to move freely inside the outer cable with no resistance. Occasionally the plastic coating on the inside of an inner cable breaks down over time causing friction not allowing the cable to move freely and change gear. This issue can also be caused due to dirt or grease build up inside the outer cabling or, corrosion/frayed inner cabling. Regularly check the cables are clean and move freely, if not they may need to be replaced or at the very least cleaned with a wipe and fresh lubricant.    

Damage:     It is rare for a shifter to fail unless very old. It is often easy to spot a failed shifter as it no longer clicks into gear, however seized cables can give the appearance that the shifter is broken when it isn't. It is however common to bend/break the rear derailleur leaning the bike against a wall or dropping it on the floor where the rear derailleur hits the surface can cause the hanger to bend out of shape. If your bike is not changing gears, ensure that the hanger has not been bent and that the rear derailleur is sitting straight.    

Setting gears:     Assuming cables are all fine and nothing is bent or worn, the only remaining cause of incorrect gearing is incorrect setting. To reset the gear tension, place the bike in the smallest gear at the rear (7th or 8th usually) undo the gear cable clamp. The rear derailleur has 2 limit screws one screw controls the maximum limit of movement towards the wheel, the other the maximum movement away from the wheel. Adjust the limit screws so that the rear derailleur can freely move down to the bottom gear, in line with that gear, and towards the wheel, slightly over the center of the gear. Be sure to push the derailleur into position in the first gear and ensure the derailleur does not go as far as touching the spokes of the wheel or allowing the chain to fall off in between the freewheel and spokes. With the limit screws set correctly, next is cable tension. Pull firmly on the cable and clamp it back down with no free play on the cable. Try each gear on the bike, if the bike does not go up the freewheel into the easier gears freely, the cable needs tightening slightly. If the gears do not go down towards the hardest gear freely the cable is too tight and needs to be loosened.


Display FAQs

The display cannot be turned on

Some batteries must be turned on first. The system is a plug-and-play system. The display cables should be disconnected once and checked for broken/bent pins. Then plug the plugs back together again, arrow to arrow.   Disconnect the plug connection from the brake lever to the display and turn on the display. If the system is working again, the E-brake lever must be replaced.   If present, disconnect the front lamp and turn on the display. If the system works again, the e-bike lamp will most likely cause a short circuit. The e-bike lamp and, if necessary, the light cable should be replaced.   The NCM Moscow, NCM Milano, NCM Venice 48V may have a loose battery connector as a cause. Unscrew the battery holder at the top and disconnect the rigid connection and plug it back together again. Check soldering point to battery plug.  if none of the above work the issue may be due to a faulty display or faulty battery.


The display is all scratched after delivery

There is a protective film on the display which must be removed.


The battery is fully charged, and the display shows that the battery is empty

There is a protective film on the display which must be removed.


The display always shows 0km/h while Riding

All wheel connectors should be disconnected and reconnected. Several tests are possible: inspect the wheel connector plugs and ensure connector pins are not bent or broken  ensure the display is connected correctly and connector pins are not broken  the speed sensor on the bike is located inside the wheel hub, if the above does not resolve the issue, it is possible one of the magnets is loose inside the motor and will need repairing/replacing.


The display shows no speed, the field is empty

This is likely a display error. Replacement display may rectify the issue


The display shows that the speed is too low / the speed is jumping regularly

If the speed is reading consistently but too high/low, it is likely that the display has the wrong wheel size. Follow instructions or watch our helpful online video on how to adjust the wheel size in the back settings of your display.  If the speed is erratic and/or intermittent it is likely that there is a loose magnet inside the wheel hub. This will need to be repaired or replaced.


The display turns off after five minutes

The system assumes that the bike is not moving and turns off automatically after five minutes. Disconnect the motor connector: The smallest pin in the middle of the plug is responsible for transmitting the speed. Plug the connector back together again, arrow to arrow, so that a contact is made and start a test drive. If this does not solve the problem, it is likely that the Hall sensor in the motor is defective.


The display shows an error code (wrench with sequence of numbers)

Code 01 - Abnormal Voltage/Current - Usually a battery problem. Battery replacement recommended.  

Code 02 - Throttle fault (Throttle Fault) - Most likely the thumb throttle is defective.  

Code 03 - Motor operational problem (motor phase problem) - A defect in the pedal sensor is likely.  

Code 04 - Motor Hall Defect (Motor Hall Defect) - 80% controller defective, 20% motor defective.  

Code 05 - Failure of the brake (Brake failed) - Pull off the E-brake lever and drive again. Replace brake lever. 

Code 06 - Under Voltage - Problem with battery connector. Mainly at the NCM Prague, corrosion or charring on the battery seat. Cleaning or replacement of battery connector.  

Code 07 - Stalling the motor - (motor stalling).  Most likely a faulty motor or controller.  

Code 08 - Unusual controller message - (Abnormal Controller Communication) Check sensor for function, otherwise check controller cable. Replace controller.

Code 09 - Abnormal Display Communication.


The menu navigation is different from the description in the operating instructions

This is likely due to a new software version.


Motor FAQs

The motor is very loud and humming

This is likely a fault within the motor itself. The motor may need to be re-greased or replaced if burnt out.


The engine sputters and stops

Check all plug connections to prevent loose connection issue. Fully charge the battery to ensure full power. It is likely a short in the electrical system or an issue with the motor itself.


The wheel cannot be moved backwards. Gearbox or controller problem is possible

Disconnect the motor connector and push the wheel backwards again. If the wheel can be pushed back again, the controller is probably defective. If it is still not possible to move the wheel backwards, the motor may be blocked. Push the wheel backwards with force to release the lock. If this is not possible, the motor must be replaced.


No motor support but everything else is normal

Check plug connections. Disconnect the E-brake lever and retest. Carefully turn the bike upside down and turn the pedals. A red light should flash regularly on the pedal sensor. If the sensor does not flash, it is most likely defective. Check the cable routing of the cables leaving the controller. These must neither be bent nor damaged. (Example: NCM Moscow 48V - controller cable may have been damaged by kickstand or gear).  

Testing the walk-mode: Lift the wheel with the motor and activate walk mode via the display according to the operating instructions. If the walk mode works properly, a defect of the pedal sensor/controller is possible.

If you are still experiencing issues with your motor, please detail your issue in writing and email cs.us@leoncycle.com 


The assistance starts very late or has a bad response

This issue may be due to one of two things. The Controller may need a software update/reflash. The pedal assist sensor is worn or incorrectly fitted and will need to be adjusted or replaced


Warranty FAQs

I need to make a warranty claim

Please read our return policy first on the home page and contact us through support.uk@leoncycle.com.