Beacon 2 Headlight FAQ

What are the differences between Beacon 2 and Beacon 1?

This is a summary of the new and improved features of Beacon 2.  These are explained in more detail in the entries below.

    • Greatly reduced flickering at low speed.
    • Low brightness mode for dynamo and external battery power.
    • Standlight is controlled by toggle switch and can be turned off.
    • Standlight charges even when the light is off.
    • Blinking mode when using external battery power.
    • Taillight output is powered by the external battery input in addition to the dynamo.
    • Regulated taillight output for more efficient taillight performance; no resistor needed when using Supernova E3 taillight.

What input power options are available?

    The Beacon can be powered by a dynamo, an external USB battery pack, or both.  An external USB battery can be connected using the barrel connector on the back of the light.  A USB-to-barrel cable is available.  The external battery will maintain high brightness and steady output, even when stopped.  When you begin riding, the power from the dynamo will begin to replace the power from the battery until you reach a speed where the dynamo is able to provide all of the power, and the battery is no longer used.  When you slow down the light resumes using the battery so the beam doesn't dim or flicker.

      How does the integrated USB charger work?

        The Beacon includes circuitry from our Revolution and Reactor chargers.  The USB output is available from a standard USB-A connector on the back of the light.  Connect your device directly to the USB port, or use a USB extension cable and put the connector anywhere you want.

          Is the USB charger always enabled?

            The USB charger is enabled when the light is off or in low brightness mode.  The charger is disabled when the light is in high brightness mode.  
            Disabling the charger in high brightness mode avoids a problem where the light might suddenly change brightness, or strobe randomly, if the device being charged changes the amount of power being drawn from the light.  
              When the light is off, all the power from the dynamo can be used by the charger.  In low brightness mode power is shared between the light and charger.  Typically about 50-60% of the power is available to the charger, so if the charger output is 500mA with the light off, it will be about 300mA in low brightness mode.

                Does the Beacon flicker when riding at low speed?

                Flickering has been greatly reduced in Beacon 2 and the light is steady down to about 3-4 MPH.  

                When using an external battery in parallel with the dynamo the light will always be steady.

                What is Low Brightness mode?

                In low brightness mode, only one LED is illuminated and the brightness is limited to 125 lumens.  This serves several purposes:

                  1. A reduced brightness mode is useful in situations where full brightness is not needed; for example to avoid dazzling oncoming cyclists on a bike path or as a daytime running light.
                  2. Reducing and controlling the power used by the light means it is not affected by using the charger.  Brightness in this mode will remain constant whether the USB charger is being used or not.
                  3. While drag from a dynamo light is typically not noticeable, the drag will be reduced in low brightness mode.

                What happened to Charger Priority Mode from Beacon 1?

                  This functionality has been replaced by the new low brightness mode.  While Charger Priority Mode attempted to better share the power between the light and charger, it was not possible to guarantee a steady brightness while using the charger.  That has been accomplished with low brightness mode which results in a much better experience of using the light and charger simultaneously.

                    Can I use an external charger in parallel with the Beacon?

                    The Beacon contains a USB charger so in general it would not be necessary to add an external charger like a Revolution or Reactor, but it is possible.  Be aware that if an external charger is used while the Beacon is in high brightness mode the light may strobe or change brightness when the external charger changes the amount of power it draws from the dynamo.

                    Can I use two Beacons at the same time?

                    It is not recommended to connect two Beacon 2's to the same dynamo.  The output of the dynamo is limited and will be shared between the Beacons so the brightness of two Beacons in parallel is about the same as one Beacon.  

                    Critically, the electronics of Beacon 2 are always optimizing the power used from the dynamo, and if two Beacon 2's are connected in parallel they can interfere with each other, leading to odd behavior.

                    It IS possible to use two Beacons on the same bike if one is powered by the dynamo and one is powered by an external battery.

                    Can I charge the same battery that I use to power the light?

                    Yes.  Because the connectors on the battery are input only or output only, you'll need to connect two cables - a USB cable from the Beacon USB port to the battery input, and a USB-to-barrel from the battery output to the Beacon barrel connector.

                    You can either leave both cables connected or connect only one at a time, depending on whether you are using the charger or the light.

                    Are there multiple brightness settings?

                      Yes.  With the switch in the UP position the light operates in high brightness mode and provides about 750 lumens. 
                      With the switch in the DOWN position the light operates in low brightness mode and provides about 125 lumens.  This can be used while riding but is also useful while setting up camp or making dinner.
                        Beacon 2 operates in these modes for both dynamo and external battery power.

                          How long will a battery last when powering the light?

                          On high the Beacon will draw about 800mA from the battery, or 4W.  On low, the Beacon will draw about 200mA, or 1W.

                          To determine battery life you'll need to know the capacity of your battery pack.  They are usually rated in mAh or Wh. 

                          If rated in Wh the battery life will be approximately (battery Wh) / (Beacon W draw).  For example, a 15Wh battery will last for about 15/4 = 3.75 hours on high, and 15/1 = 15 hours on low.

                          If rated in mAh, be aware that battery makers use the internal 3.7V battery voltage, rather than the 5V output voltage, which results in a higher number.  The math works out to (battery mAh) / (Beacon mA) x 3.7 / 5.  You are essentially converting to W and Wh and then following the math above.

                          Note that this calculates battery life when using only battery power.  When also using a dynamo the battery usage is greatly reduced, even at low speeds.  Actual battery life will depend on your speed but should be much longer than when using only a battery.

                          How bright is the light?

                            Peak output when using dynamo power is 750 lumens.  A 6V/3W dynamo in a 700c wheel reaches this output at just 13 MPH.
                              Battery powered output is 550/125 for High/Low.
                                Dynamo power is optimized at low-to-medium speeds, providing much more light in this range than any other headlight.  Beacon 2 provides 100 lumens at 5 MPH, 375 lumens at 8 MPH, and 600 lumens at 10 MPH. 

                                  What shape is the beam?

                                    The beam is round/symmetrical.  This makes the Beacon an ideal choice for bikepacking, mountain biking, or any offroad riding.  The Beacon can be used on-road as well.

                                      Can I use a dynamo taillight?

                                        Yes, the Beacon includes a taillight output wire.  The taillight is controlled by the headlight, turning on and off along with the headlight.

                                        The taillight is powered by both the dynamo and external battery input.

                                        The Beacon is compatible with taillights that do not ground to the bicycle frame.  See this page for more information.  Contact us if you have questions about a particular taillight.

                                          Is there a standlight?

                                            Yes.  A supercapacitor is charged while riding and will provide more than 5 minutes of "be seen" light when stopped.
                                              The standlight can be turned off with the toggle switch.  Any stored energy will remain and the standlight can be turned on again later.
                                                If using an external USB battery the light will use the battery and remain at the selected brightness level indefinitely.
                                                  The supercapacitor is only charged from the dynamo.  The external battery will not charge the supercapacitor.  This is typically preferred as the battery itself provides power when stopped. 
                                                  The standlight will be charged while riding even if the light is off.  This means if you ride with the light off, stop for the night, and need a little light at camp, the capacitor will be charged and provide light when you turn the toggle on.

                                                    Is the Beacon waterproof?

                                                      Yes, the Beacon can be used in the rain and can be left outside.

                                                        How is the Beacon so waterproof with open connectors?

                                                          Multiple seals on the lens side protect against water ingress.  On the connector side, all connectors are designed for resistance to the elements, and the electronics are potted in epoxy.

                                                            How do I install the Beacon on my bicycle?

                                                              The 10mm mounting tab is compatible with mounting hardware from B&M, Supernova, Schmidt, etc.  There are options for mounting to the fork crown, handlebars, fork blade/dropout, front rack, and other locations.  We also have a GoPro adapter available.

                                                                What if I have limited clearance behind the headlight?

                                                                  We have space-saving right-angle cables available.  These cables also allow the wires to easily follow the mounting hardware for secure wire management.

                                                                    Can I install the Beacon upside-down?

                                                                      Yes.  The beam is symmetrical so there will not be any optical problems if the light is mounted upside down.  There is a small drainage hole in both the top and bottom of the light so water ingress will not be a problem.

                                                                        Is there a blinking mode?

                                                                        Yes, when powering the Beacon from an external battery you can set the light to blink in low brightness mode.  

                                                                        When the switch is set to the DOWN position it will enable low brightness mode.  Each time the switch is moved to the DOWN position it will toggle between steady and blinking mode.  For example if the switch is DOWN and the light is steady, move the switch to the middle, then back to DOWN.  the light will blink.  Repeat these steps to go back to steady mode.

                                                                        Blinking mode is only enabled when using external battery power.

                                                                        Can I replace the dynamo wire?

                                                                        The dynamo wire is soldered and potted in place inside the Beacon so it can not be removed and replaced.  In case of damage or a wire that has been cut too short we recommend splicing on a new section of wire or adding quick-release connectors.

                                                                        Do you have any recommended USB battery packs?

                                                                        When using a USB battery to power the Beacon, a maximum output current of at least 1A is recommended.  Any modern battery pack should be able to provide this.
                                                                          Most USB battery packs are very flexible and do a great job charging from the Beacon, even at low speed.  If you simply want to charge a battery while riding and use it later to charge your devices, almost any battery pack can be used.
                                                                            If you want to use your battery like a buffer, and connect from Beacon to battery and battery to USB device, you need a battery that supports 'pass through charging'.  This feature is not always clearly advertised and is implemented differently by different brands. 

                                                                              What if I have a question that isn't answered here?

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