Serfas DART 500W Step-Over User manual

DART 500W / DART 350W
OWNER’S MANUAL
SERF AS
®

SERFAS DART 500W / DART 350W
OWNER’S MANUAL
Thank you for purchasing a Serfas Dart 500W/350W ebike! Before riding, please take a
moment to review these instructions.
Need service or support? Visit our website for quick answers, manuals, and/or give us
a call and we’ll find you a solution.
Serfas, Inc
2333 W Utopia Rd
Phoenix, AZ 85027
Phone: [phone]
Email: [email protected]
Version 1 (March 1, 2020)
Latest version can be found: www.serfas.com
Dart 500W / Dart 350W
Step-Over
Dart 500W / Dart 350W
Step-Through

CONTENTS
Display / Control Specifications 1
Getting Started 2
What’s on the Display? 3
Using the Controls 4
Customizing the Display 5
• Function 01P
• Function 02P
• Function 06P
Backlight Brightness
Unit of Measure
Odometer Reset
6
7
8
9
10
13
14
16
Battery and Charging
Maintenance and Service
Storing Your Bike
Safety
Error Codes and Troubleshooting
Additional Troubleshooting
Battery Troubleshooting
Frequently Asked Questions
Warranty Information 19

1
DISPLAY / CONTROL SPECIFICATIONS
•36 Volt Power Supply (350W)
• 48 Volt Power Supply (500W)
• Current Rated: 10mA
• Maximum Operating Current: 30mA
• Power Off Leakage Current < 1uA
• Operating Current to Controller: 50mA
• Operating Temperature: -18º to 65ºC
• Storage Temperature: -30º to 80ºC
Figure 2
M BUTTON
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SERFAS EBIKE OWNER’S MANUAL
Figure 1
POWER SWITCH
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Figure 3
CHARGING PORT
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GETTING STARTED
The Dart 500W/350W is operated using the control pad on the
handlebars. The control pad is located near the left-hand brake lever.
First, push the power button on the battery to turn on (Fig. 1). The
current charge level will be temporarily displayed on the LEDs (4=full,
1=near empty), then one green LED to show the battery is turned on.
Next, press and hold the M button on the handlebar controls to turn
on the display (Fig. 2). Display should light up. Now, your e-bike is ready
to ride. To turn off, press and hold M for 3 seconds. The battery will
automatically turn off.
The Dart 500W/350W bike offers pedal assist. When using pedal assist,
an electric motor supplements the riders own effort. To use the pedal
assist, simply start pedaling, then push the 'U' arrow to increase assist
or 'D' arrow to decrease pedal assist (Fig. 2). 0 is the lowest 5 is the
maximum. Pedal assist will engage at speeds up to 28 MPH (Dart
500W) or 20 MPH (Dart 350W).
The � Dart 500W/350W ebike is equipped with a throttle, which is
mounted near the rider’s left thumb, to propel the bike without
pedaling. To use the throttle, start pedaling (one pedal revolution)
then push down on the throttle while pedaling. Once the bike is
moving on throttle power, you can stop pedaling entirely and use
your thumb to control the speed of the bike. The throttle can propel
you at speeds up to 20 MPH.
The motor stops when you:
1) Stop pedaling 2) Squeeze the brake levers 3) Release the throttle.
Simply start pedaling again and re-engage the motor.
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WHAT’S ON THE DISPLAY
While you are riding, you can use the display to monitor your
speed, the amount of pedal assist, battery life remaining, and
other data.
As shown below, your Dart 500W/350W uses an LCD display
screen that looks like this:
SPEED INDICATOR
(Current / Max / Average)
5 LEVELS OF ASSIST
(0: No Assist. 5: Max Assist)
WALK MODE
(On / O)
DISTANCE INDICATOR
(Current Trip / System Mileage)
ERROR CODE INDICATOR
(In the Event of a Problem)
BACKLIGHT INDICATOR
(On / O)
BATTERY LEVEL INDICATOR
(Current / Max / Average)
VOLTAGE OUTPUT INDICATOR
(Real-Time)
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4
USING THE CONTROLS
START UP: To turn on your bike, push the power switch on the battery
(Fig. 1), then press and hold the “M” button for 3 seconds (Fig. 2).
To turn off, press and hold the “M” button for 3 seconds (Fig. 2), then
press and hold the power button on the battery for 2 seconds. The
display and battery have an energy-saving feature, if there is no
activity for 10 minutes, they will turn off automatically to preserve
battery life.
Push the “U” or “D” arrows to change the level of pedal assist (Fig. 2).
Hold “U” and “M” for 3 seconds to switch between showing real-time
speed, average speed, and max speed (Fig. 2).
Push “M” to toggle between the display of the Odometer, Trip
Distance, Voltage, and Elapsed Time.
BACKLIGHT: Press and hold “U” for 3 seconds to enable the
backlight on the display. Press and hold “U” again for 4 seconds
to turn it off (Fig. 2).
WALK MODE: To enable walk mode, first come to a complete stop
and stand next to the bike. Press and hold “D” for 3 seconds. The bike
will slowly move forward at 3.5 MPH / 6 KPH as long as you hold the
“D” button. This feature is useful for pushing the bike up a hill or
walking through a crowd, where you cannot safely ride.
“Super walk mode” is an even-faster version of walk mode. To use it,
hold the down arrow to engage standard walk mode, then press the
throttle. This is useful on very steep climbs or when towing a trailer.
Use caution with both walk modes.
SERFAS EBIKE OWNER’S MANUAL

CUSTOMIZING THE DISPLAY
You can use the settings features of the display to customize the
Dart 500W/350W for your use. To enter the “Settings” mode,
hold the “U” and “D” buttons at the same time for 2 seconds.
You can customize 3out of the 6 different functions on the
display. Push the “M” button to move from function to function,
and use the “U” and “D” arrows to adjust each to your
preferences. When you are finished, press and hold the “M”
button to save your changes. Note: The system will save your
changes automatically after 8 seconds.
FUNCTION 01P - BACKLIGHT BRIGHTNESS
You can control how bright you’d like the display backlight
to be. 1 being the dimmest and 3 is the brightest.
FUNCTION 02P - UNIT OF MEASURE
You can toggle between miles or kilometers, based on your
location and preference.
FUNCTION 06P - ODOMETER RESET
The odometer tracks the distance you’ve ridden over the
lifetime of your bicycle. Press and hold “U” for 5 seconds to
reset the trip distance from a single trip.
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BATTERY AND CHARGING
The Dart 500W/350W uses a Lithium-Ion battery which can be
charged on or off the bike. We recommend charging the battery
off the bike indoors, in moderate temperature conditions. To
charge the battery, plug the charger into the charging portand
then connect the charger to a wall outlet (Fig. 3). The LED
indicator light will be red when charging and will turn green
when charging is complete. When finished, unplug the charger
from the battery and from the wall outlet.
Take care of the battery to ensure a long service life:
• Charge and store the battery indoors if possible. The
battery can be removed from the bicycle for this purpose.
• Avoid extreme hot and cold temperatures.
• DO NOT submerge your bike or any of the components in
water. This action will void the warranty.
To optimize the performance of the battery over time, try and use
it (discharging and charging) at least monthly. But if you won’t be
riding your Dart 500W/350W for an extended period of time, it’s
best to store the battery fully charged. EVERY 2 MONTHS: Put
battery on the charger to maintain optimum level.
After many charging and discharge cycles, runtime and range will
be reduced. Replacement batteries are available from Serfas to
extend the life of your ebike. The lifespan of the battery is about
500 charge / discharge cycles for properly maintained batteries.
When you install the battery on the Dart 500W/350W, it locks into
place automatically. To unlock for removal, use the supplied key.
DO NOT ride the bicycle if the battery rattles or moves - it
should be firmly attached.
The Dart 500W/350W battery contains a USB port for transmitting
diagnostic data only, not for charging. It will not charge or power
devices via USB.
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MAINTENANCE AND SERVICE
• When cleaning your bike, use a damp cloth and gentle dish
soap. Note: DO NOT use a pressure washer or sprayer.
• Periodically apply a light lubricant to moving parts,
including the links of the chain, derailleur pivots, and shifter
cable inner wire where it enters the cable housing.
• If you ride in wet / humid environments clean and dry
electric connections and apply an anti-corrosive.
All bicycles will need a periodic tune-up or adjustments by a
professional. An annual “check-up” is beneficial. Your bike’s
service schedule will depend on the frequency of its use. In
between expert services at a bike shop, we suggest:
• Keep tires inflated to their recommended pressure (30-50
PSI / 2.0-3.5 BAR / 200-350 KPA) and check weekly.
• Clean the drivetrain and lubricate the chain (monthly)
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STORING YOUR BIKE
From time to time, you may wish to store your bike for an
extended period without riding. Proper storage can help prolong
the life of your ebike components and battery.
To prepare to store your bike, first fully charge the battery.
Then remove the battery from the bike and store it separately.
Removing the battery from the bike puts it into a low-voltage state
designed for long-term storage.
Keep both the bike and battery in a cool, dry place. Avoid
both very hot, and very cold temperatures. Generally if the
environment is comfortable for humans, that’s a good place to
store your bike.
Store your bike away from sources of heat, UV light, and ozone,
all of which can prematurely age rubber tires and tubes.
All bicycle tubes slowly lose air over time and need to be
regularly topped o to maintain proper pressure. This does not
mean that your bicycle has a flat tire. Avoid allowing the tires to
deflate completely during storage
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SAFETY
You should wear an approved ebike bicycle helmet every time you
ride a bicycle, regardless of the legal requirement to do so.
Additionally, some jurisdictions require helmet use when riding
Class ll and Class III ebikes like the Dart 350W and Dart 500W.
Your Dart 500W/350W comes with reflectors and we encourage
you to use them. Reflectors are not a substitute for lights, which
are not included with your bicycle. You should purchase, install,
and use front and rear lights when riding in dim or dark conditions.
Some jurisdictions restrict where ebikes can and cannot be ridden.
These limits may include specific speeds and motor wattages.
Your Dart 350W is a Class II ebike, 350 watts with pedal assist up to 20
MPH and throttle up to 20 MPH. You should only ride it where legal
and safe.
Your Dart 500W is a Class III ebike, 500 watts with pedal assist up
to 28 MPH and throttle up to 20 MPH.
Some jurisdictions do not allow throttle controlled ebikes. Your
Dart 500W/350W will run without the throttle plugged in and
removed from bicycle.
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ERROR CODES AND TROUBLESHOOTING
In the event of a problem with the electrical components of your
bike, the display will show an error code. Compare the code with
this list below and HOW TO RESOLVE:
CODE ERROR HOW TO RESOLVE
21 Current
Error
Check the cable that connects the
rear hub motor to the rest of the
system. Make sure it is free from grit or
contaminants and is firmly connected.
22 Throttle
Error
When you press and release the throttle,
it should return to the original position.
Remove any obstructions. Check the
throttle and throttle cable for damage,
such as a cut or frayed cable.
23 Motor Phase
Error
Check the cable that connects the rear
hub motor to the rest of the system
and make sure it is free from grit or
contaminants and is firmly connected.
This error might appear if you don’t
reconnect the cable after removing the
rear wheel (for example, after changing
a flat tire, or transporting your bike in the
trunk of a car). At least one of the motor
phase wires has been damaged or is
temporarily disconnected.
24 Motor Hall Sensor
Error
The hall sensor inside the rear hub might
be disconnected or damaged. Service or
replace the rear hub.
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25 Brake
Error
The Dart 500Wuses special brake levers
that stop the motor when you apply the
brakes - built in “magnetic reed switches”
disengage the motor’s power when the
lever is squeezed. If the lever is damaged
(for example, following a crash), it might
need to be replaced.
26 Overheat
Error
The controller or motor has overheated
from extended periods of extremely
heavy use (for example, climbing a steep
hill with maximum pedal assist applied.)
Turn o the bike, allow the components
to cool o, then try again.
28 Low
Voltage
The voltage supplied by the battery is
too low to operate the bike. Charge the
battery and try again. If the issue persists,
check the voltage output on the battery
terminals using a volt meter.
29 Over
Voltage
The battery is supplying too much
voltage to the controller. Make sure you
are using the correct battery for your
bike. For example, the 36V Dart 350W
battery will not work with the 48V Dart
500W, triggering the error.
30 Communication
Error
Poor connection between the controller
and the display, check all cable
connections.
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38 Battery Voltage
Error
The battery is not supplying the required
voltage to power the display and motor.
Use the display to view the real-time
voltage being output from the battery. It
can also be checked using a volt meter. If
the battery is old and has been charged
/ discharged many times, it may need to
be replaced. This error could also appear
if you install the wrong battery on your
Dart 500W/350W.
E1E Communication
Error
Bad connection between display and
controller, disconnect and re-connect
display; ensure connection does not
have grit or contamination.
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ADDITIONAL TROUBLESHOOTING
Having trouble with your Dart 500W/350W? Most problems
are easy to correct.
1. Start by making sure you have a charged battery.
2. If the motor of your bike will not engage, or only engages
intermittently, double check the cable connection where the
rear wheel motor plugs into the rest of the system. This
connector must be firmly and fully plugged in to function
correctly. If necessary, loosen the clips holding the cable to
the frame to create additional slack in the cable, then re-
tighten the clips after you have the motor cable firmly plugged
in.
3. The throttle on the Dart 500W/350W will only engage after the
motor is turned on via pedal assist. This is a safety feature
designed to prevent you from accidentally engaging the
throttle while parking or walking the bike. If you have having
difficulty with the throttle, remember to make one revolution
of the pedals first, then engage the throttle. You can stop
pedaling after the throttle function turns on.
4. If you bent the derailleur hanger on your Dart 500W/350W in a
fall, don’t worry. It’s actually designed to fail, sparing the more
expensive frame, and is inexpensively replaceable for this
reason. If you need another, they are available on
www.serfas.com or at partner bike shops.
5. If your bike powers up normally and shows no error messages,
but will not run when you turn the pedal assist on, check to
ensure the cadence sensor under the left crankarm is plugged in.
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BATTERY TROUBLESHOOTING
Your Dart 500W/350W ebike battery uses several sophisticated
monitoring systems to prevent damage from overcharging,
overheating, deep battery discharge, charging with the wrong
voltage, and other errors.
Please use the specific charger supplied with your bike. Other
chargers may not supply the correct voltage required for
charging. Those that do may not be programmed to initiate the
charge cycle. To resolve this:
1. Remove the battery from the bike.
2. Plug the charging tip into the battery.
3. Plug the charger into wall power.
4. Tap the power button on the battery once to turn it on.
5. Charge the battery overnight.
6. When charging is complete, put the battery back on the
bike and check for proper operation. Having trouble with
your Dart 500W/350W? Most problems are easy to correct.
If a situation occurs that could damage the battery, the battery
can go into a protective “sleep mode” - the battery cells inside
are OK, but the battery won’t turn on and won’t take a charge.
To “wake up” the battery, please follow this procedure:
1. Put the battery on the bike.
2. Plug the charging tip into the battery.
3. Plug the charger into wall power.
4. Tap the power button on the battery once to turn it on.
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5. Press and hold “M” on the controls to turn on the display.
6. Allow the battery to charge overnight.
7. Once charged, remove from wall power and check for
proper operation.
Under specific circumstances you might see one single LED
flashing constantly on the battery. One blinking LED is a warning
of excessive strain on the battery for its charge level. To correct
this issue:
1. Reduce the strain on the battery and charge the battery. If
it will not take a charge, please take the previous steps to
resolve the issue.
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FREQUENTLY ASKED QUESTIONS
• Do components from the Dart 500W and Dart 350W
interchange?
Some components interchange across the line of Dart ebikes,
like saddles, seatposts, handlebars, and grips. The ebike-
specific components, however, like batteries, controllers,
displays, and motor do not interchange. Dart 350W is a 36V
system vs. 48V on the Dart 500W and these parts are not
compatible.
• My Dart ebike is too fast, or exceeds my local speed limit, or
only Class I ebikes are allowed on my favorite bike path.
Dart ebikes can have the speed limit changed using the
settings in the control panel and can be set as low as 14 MPH
if desired to comply with local laws. Dart ebikes can also have
the throttle unplugged and removed (but will continue to run
on pedal assist) if desired in locations where throttle bikes are
not permitted.
• On the Dart line of ebikes, I can’t use the throttle from a
dead stop, only once I’m pedaling. Why?
This is a safety feature to prevent you from accidentally
engaging the throttle while parking or standing with the bike,
if you forget to turn it off and then hit the throttle accidentally.
You can engage the throttle at any time while you are
pedaling. If you are at a dead stop, you can push the throttle,
start pedaling (about one pedal revolution), then stop
pedaling, and the bike will stay in throttle mode.
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• How many times can I recharge my ebike battery?
Lithium-Ion ebike batteries use a similar technology to your
laptop or mobile phone. They can absorb about 500 charging
cycles before performance starts to degrade. Afterwards, they
can continue to be recharged, however, their capacity will
decrease.
• Can I put a suspension fork on the Dart ebike?
Yes, it is possible to put a suspension fork on the Dart line of
ebikes. You would need a replacement fork with these specs:
1 1/8” to 1.5” tapered steerer tube, 51mm IS mount for disc
brakes (or a 74mm mount with an add-on adapter to 51mm),
27.5” / 650B wheel size, and the quick release / open type
dropout style. Selecting and installing a suspension fork is
probably a job for a bike shop.
• Can I put a suspension seatpost on the Dart ebike?
Yes, you can add a suspension seatpost to your ebike. Shop
for a model with the same diameter as the seatpost you are
replacing. The seatpost diameter is stamped on the post, near
the minimum insertion mark.
•Do I have to wear a helmet when riding an ebike?
We suggest you do. This depends on your age, and your state.
Check local laws.
•What rear rack fits the Serfas Dart e-bikes?
We recommend to check with your local bike shop.
•How should I care for my e-bike battery?
Please read this article, Caring for your ebike battery.
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