My day job involves working with and designing parts of radar systems, so I was delighted to recently be offered the chance to try out a bike tail light with a built in radar for detecting approaching vehicles. The systems I work on are massive in comparison to this and it is actually really impressive how something so small can be produced and how well it works. 


As vulnerable road users it’s always important to look at ways in which we can make ourselves safer. The obvious ones are helmets to mitigate any collision, hi-viz clothing to make ourselves more visible and lights to both light up the road and make others aware of our presence.

Over my years of cycle commuting I have tried many different types of light: pulsing, high output, laser markings, and all in a multitude of different packages. One of the best features though is radar detection that is built into the Magene light here. I have actually been a user of the equivalent Garmin product (first gen) that does much the same, so feel well placed to provide a review. The Garmin unit is now 6 years old and still works well, however the battery does not hold as much charge as it used to.


The device Magene sent me is the L508 Radar Tail Light. First impressions after unpacking are that it is good quality and a good looking product. Included in the box are the light itself, a seatpost mount with insert for various shapes of post, a variety of rubber bands to attach this and a fairly generic charging cable (USB Type-C). It’s actually a much nicer design than the original Garmin Varia, although the latest version of that looks quite similar to this one.

Light Output

Although the main selling point of this light is the radar feature, it does also have a very nice set of general options. There are 7 different light modes available: solid, flashing, pulse, peloton, quickly flash, rotation and single radar mode. These can be chosen by simply pressing the main button on the device to cycle through the options, with the light remembering the last one used and powering up in this mode the next time. 

The single radar mode does not have any illumination on by default and operates in radar detect, with it lighting up when a vehicle is found to be approaching. This is the mode I have been using almost all the time recently as we still have lots of daylight here and I am not riding in the dark much. I’ve put a video later to show this detection in operation.

Claimed run times are quite acceptable for a rear light, with the official figures shown below:

  • 4-11h (solid mode)
  • 10-16h (peloton mode)
  • 15-18h (quickly flash mode)
  • 11-13h (pulse mode, flash mode)
  • 10-12h (rotation mode)
  • 19h (only radar mode)

Real world use will vary depending on where you ride, temperature, and how many radar detections are made. Generally I find that one charge is enough to last me a full week of riding, at which point I start to get warning messages on my Garmin head unit that the battery level is low. This is currently averaging around 10-12 hours.

Radar Mode

The light has 2 modes of connecting in order to control things: via Bluetooth and a Magene app, and via Ant+ to connect to a Garmin Edge unit (or similar). Initially I connected it to my Garmin Edge, which was very simple but when trialing it out on the road the detections I was being shown did not in any way match up to what was happening on the road. I think it was still in some kind of demo mode, where it would simulate vehicles coming from behind you. I tried connecting to my phone app and running the radar mode from there. This seemed to have the effect of enabling things properly so that when I returned to the Garmin Edge unit it was setup correctly and displaying real world detections for me.

When connected to the Garmin Edge, a bar is shown on the right hand side of the screen with dots moving from bottom to top as cars are within range. It can cope with up to 8 individual vehicles at a distance of up to 140m away. An audible beep is heard when one first appears and another slightly different one when it passes. This works very well and minimises the need to be constantly checking the display. You can turn off the noise if it gets annoying but I find it too useful.

As well as all this, the device will also flash a warning when it first detects something. It keeps doing this for each successive vehicle even when the others are still within range. Check out the video below for an example of it in use:


Another neat feature is the ability to detect your braking using an on board accelerometer. When this is detected it will light brighter for 3 seconds to warn those behind you. This feature can be disabled if not wanted and I’ve not actually tested how well it works as I have always had it mounted behind me.


Overall I have to say I am mightily impressed with the Magene Radar Tail Light. It is very easy to use, works well as both a light to be seen and a radar to warn of approaching vehicles. The radar is not going to be a replacement for your eyes and ears as there will always be the chance that something will be missed. However it does give a good early warning and provides a comfort and peace of mind. I find it especially good when there is a lot of wind noise as this can sometimes mask out a vehicle.

The cost is obviously going to be quite a bit higher than a basic tail light, and is currently available for £109.99 at Amazon.

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Comments (2)

  1. koeroeur


    I have this for about two weeks now. It’s going be returned. A LOT of false positives and battery life is awful. I started this morning with 40% battery and ended up with 9% 45 minutes later. Lights were off, except brake light. So that’s baout 3 hours of battery life…

    • Reply

      Sounds like a dodgy unit or maybe not set up properly. The many false positives could be impacting battery life? Did you go through the mobile app and check firmware?

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