Magicshine SEEMEE R300 Smart Radar Taillight
Magicshine has long been a leader and innovator in the cycling illumination, churning out innovative gear. While their latest offering, the SEEMEE R300 Smart Radar Taillight, isn’t the first radar taillight to hit the cycling world, it’s a bold step for Magicshine, packed with unique features that set it apart. Engineered to go head-to-head with other radar taillights, it enters the market at a more budget-friendly price point.
Some reviews have advised steering clear of this device, but how does it hold up under JayLo’s rigorous testing? Let’s dive in.
Right now, the Magicshine SEEMEE R300 Smart Radar Taillight is currently 25% off at $97.49 USD, typically $129.99. This spring deal puts it $50 USD less than other rival radars when they are at their lowest sale prices. Act fast on this offer – won’t last long.
If you are interested in some other light products, check out some of these other reviews:
Magicshine Allty 1200U headlight, Magicshine SEEMEE 50 MAG/V2.0 taillights, Magicshine SEEMEE DV camera taillight, and one of my personal favorite headlights, Magicshine EVO 1700
What is Radar?
Radar, short for Radio Detection and Ranging, harnesses radio waves to measure distances, directions, and radial velocities of objects relative to the device. These measurements are relative to the radar device. These modern systems were developed in the 1940s, but the initial ideas go back to the 1880s.
Best known for weather forecasting and military operations, radar is now revolutionizing cycling, boosting rider safety.
Radar is also known for having quite a few limitations, and with these devices being small and not very powerful, it will be interesting to see if weather has a large impact on its performance.
Unboxing
The Magicshine SEEMEE R300 Smart Radar Taillight comes with the SEEMEE R300, round seat post mount, aero seat post mount, USB-A to USB-C charging cable, and a user manual. Note that the seat post mounts provided are only the rubber portion of the mount, and there is only one plastic quarter-turn portion of the mount.
Thus, only one mount can be used at a time. A puzzling oversight. The plastic portion of the mount probably costs very little. Magicshine could’ve either skipped the aero strap to cut costs or, better yet, included two full mounts for maximum versatility.
Charging
Use the supplied USB cable to charge the device when you receive it. Click the power button and the light on the top will turn on for 3 seconds:
- Green: 40-100%
- Solid Red: 11-39%
- Flashing Red: 1-10%
Peel back the rubber cover on the left side to access the USB-C port on the Magicshine SEEMEE R300. Once charged, insert the rubber cover to protect from water intrusion. Standard charging takes about 2.15 hours at 5V 2A.
The charge port opening is small, so some aftermarket USB-C charging cables may not fit. You will most likely need to use the one provided to charge the SEEMEE R300.
Like other Magicshine lights I’ve tested, the battery gauge is frustratingly vague, especially the green range (100–21%). I suggest adding a flashing green indicator and adjusting the ranges:
- Solid Green: 100-75%
- Flashing Green: 74-50%
- Solid Red: 49-11%
- Flashing red: 10-1%.
Installation
The installation of the Magicshine SEEMEE R300 Smart Radar Taillight is very easy. Take the seat post mount, wrap the strap around the seat post, then slip the strap onto the T-shaped hook. Once the mount is installed, attach the SEEMEE R300.
The Magicshine SEEMEE R300 attaches to the mount by inserting the quarter into the mount then rotating the light 90 degrees. Start with the light in a horizontal position, then rotate the light downwards.
Its proprietary quarter-turn mount mirrors the rock-solid Garmin design but in a compact form.
The mount is made from two pieces, the plastic quarter-turn part with a hook and the rubber strap. The strap slides through a hole on the quarter-turn portion and then the circular piece of rubber fits into the mount.
Depending on the seat post you will be mounting it to (round or aero), there are two styles of rubber straps. The aero version has a deep V-shape to lock into typical aero-shaped seat posts, whereas the round version has a rounded groove.
Ideally, the Magicshine SEEMEE R300, when installed, will be vertical. Depending on the angle of your seat post it might not be. To keep the radar beam clear of the tire, position the taillight as high as possible on the seat post.
Specs
- Max Output: 300 Lumens
- Max Runtime: On Eco Flash – 100 hours Radar off; 24 hours Radar on
- Radar Frequency: 24 GHz – 24.25 GHz
- Maximum Detection Distance: 140 m
- Maximum Detection Targets: 8
- Horizontal Detection Angle: 35°
- Vertical Detection Angle: 45°
- Relative Speed of Detectable Targets: 5-100 km/h (3.1-62.1 mph)
- Wireless Protocol: Bluetooth, ANT+
- Visibility Angle: 270°
- Battery: 3.6V 3350 mAh
- Lens/Reflector Type: PC optical lens
- Charging Time: 2.15 hours (5 V, 2 A)
- Water Penetration: None Given
- Charge Port: USB-C
- Weight: 3.99 oz (113 g)
- Dimensions: 3.78 in x 1.14 in x 1.34 in (96 mm x 34 mm x 29 mm)
- Material: Aluminum + Plastic + Rubber
Initial Thoughts
Radar taillights aren’t exactly revolutionary, having debuted in 2015 with scant competition until 2022. I have been familiar with these products for many years, but never really had much interest in them.
I can’t really pinpoint any particular reason why I didn’t get one, but price would probably have been the main factor. Second would be that I never really looked into them to truly appreciate the technology. I think the first radar taillight released on the market wasn’t necessarily very aesthetically pleasing.
Nowadays, if you go on almost any group ride of any level, you are sure to find riders with a radar taillight.
I finally took the plunge in 2024, got my first one, and haven’t looked back. With Magicshine releasing a version of their own, I am happy to see some competition in this space to hopefully spur on innovation all around. I think some of the features of the Magicshine SEEMEE R300 taillight will surely spark some motivation in other companies to modernize their devices (I hope).
The Magicshine SEEMEE R300 as a taillight seems to be good. It has a main light at the top center of the light and two additional LED strips on the lower portion that shine off to the sides to give the rider more visibility from the wide light patterns.
If you saw my review of the SEEMEE DV, then this taillight will look very familiar. The body of the lights is very similar, and my guess is that the SEEMEE DV platform was the basis of design from the SEEMEE R300. Though the SEEMEE DV is a camera taillight, maybe soon Magicshine will integrate the two and have an additional offering in their lineup.
As far as the radar portion of the taillight, there isn’t much to talk about here. It seems to have similar specs to other radars on the market, so no boundaries are being pushed here. If it can match the performance of the other brands, I will consider that a good radar taillight for their first attempt, but that is yet to be determined.
Looking at the specs of the light, it has a better battery life than other taillights available, and the light brightness is much better, too.
Apparently, some countries in Europe do not permit cyclists to use blinking lights, and I think the light can only be a certain brightness, too. You may want to check your local laws to see if this light is permitted for use in your area. Currently, in the US, it is legal to use.
Operating Instructions
The Magicshine SEEMEE R300 device has similar functioning to the SEEMEE DV. There are two buttons on the top of the light to control the different functions of the light.
On/Off – Press and hold the power button to turn on and off. The light will turn back on to the last mode the light was on when it was last turned off.
Enable/Disable the Radar – The radar is automatically turned on by default when you turn the light on, even if it was off the last time the light was turned off. To turn the radar off or back on when the light is on, press and hold the radar button until the radar indicator light turns on/off.
Change Light Modes – When the light is on, click the power button to cycle through the different modes. The modes are Low – High – Night Flash – Day Flash – Eco Flash. Light modes can also be changed on your bike computer (see Magicshine for compatible devices).
Vibration Function – This mode will make the light enter sleep mode after 5 minutes of inactivity and will turn back on when a vibration is detected. To turn on, with the light off, press and hold the power button and radar button at the same time for three seconds. The light will turn on to max output, then switch to the last mode the light was set on. Do the same to turn the vibration function off, but this time the taillight will flash, then switch to the last light mode.
Lockout/Unlock – Press and hold the power button for three seconds to lock/unlock the light. If you click the power button when it is locked out the light indicator on the top will flash red
Radar/Light Modes
The Magicshine SEEMEE R300 has two solid light modes: Low (15 LM) and High (50 LM), and three flash modes: Night Flash (10-50 LM), Day Flash (0-100 LM), and Eco Flash (0-3-3-10 LM). There is also a mode that is only accessible when other Magicshine lights are nearby, Group Ride Mode (5 LM). In Radar Mode, there is a ring LED around the main light that illuminates when the radar is on and is 1 LM.
There is a secondary set of flash modes that occur when a vehicle gets within 70 m (230 ft). This sends an initial 300 LM flash then dims to a gentler flash:
- Radar Night Flash: 0-60 LM (Eco Flash, Low, or Night Flash)
- Radar Day Flash: 0-300 LM (High Mode or Day Flash)
PelotonSync Flash Mode
A new feature coming on Magicshine taillights is the PelotonSync mode. For the light to go into this mode, a second light needs to come into close proximity and be in the same flash mode.
The idea behind PelotonSync is, if you are riding in a peloton, or a group of riders, and all the lights are in the same flash mode, the lights will flash synchronously. Thus, instead of a bunch of taillights flashing in a random pattern, all the taillights will flash at the same time.
I think this feature can increase rider safety because a group of riders with lights that are flashing in the same pattern may be more visible. Also, a group of riders with lights flashing randomly can be a little bit more of a distraction to oncoming drivers.
This isn’t really a flash mode though; it is a feature that syncs the light flashing so that they flash at the same time.
FTR LightSync Control
This feature allows the light to be paired to the remote control that comes with the Magicshine ALLTY 1200U headlight. Once the remote is connected, the light can be turned on and off with the remote.
With a click of the remote, the headlight and taillight will turn on/off. What is also cool, once the lights are paired, the taillight can be controlled from the headlight power button. So, if you forget the remote control, the taillight can be turned on/off from the headlight.
This is a neat feature that allows for the control of multiple lights with just a click of a button. This will help with forgetting to turn on/off your taillight, too.
Low Power Mode
When the battery of the Magicshine SEEMEE R300 taillight drops below 10%, the light mode will change to Eco Flash. The radar flash mode and vibration function are also disabled. This is a nice feature that prioritizes your visibility to motorists while extending the battery life as much as possible.
Connecting to Bike Computer or Phone
Connecting to a bike computer is very easy and is very quick. Depending on the computer model you have, the process might be slightly different. For a Garmin Edge 840 Solar or a Hammerhead Karoo 2, it is basically the same way. Go to sensors, search for Radar, and when the device name pops up, select it. There are a few settings that you can change depending on your preferences.
Depending on the app you use to record the data with or the phone you use, the process might be slightly different. For me, I connected the device in the Bluetooth settings of the phone, then in the app, selected the radar for my connected devices.
On Screen Radar Indication
Bike computers and apps display approaching vehicles differently:
- Garmin: A white dot represents the vehicle, with a colored dot at the top indicating threat level (orange for low, red for high, green when the vehicle passes). A radar connection symbol appears in the top right, which may obscure other data.
- Hammerhead Karoo 2: A vehicle-shaped icon is used, with a yellow/red strip indicating threat level. No on-screen radar connection symbol is provided.
- Apps: Display varies by app, often like Hammerhead’s approach.
Light Performance
I won’t linger too long on the light’s performance—it feels almost beside the point for a radar taillight. I believe most people won’t purchase the Magicshine SEEMEE R300 taillight for its light performance. It is quite an expensive taillight if one isn’t using its radar functionality.
Magicshine has many other lights, which I have reviewed, that have the same features (PelotonSync, FTR LightSync, etc.), and those other taillights can be had for a quarter of the price.
The taillight portion of the light is quite bright, and the lower vertical LEDs angle outwards to give a wide pattern to make you highly visible day or night. In terms of light performance, it is better than the Varia, and makes you more visible, too.
Magicshine knows lights, and the SEEMEE R300 light portion is quite impressive.
Radar Performance
If you have seen any of the Magicshine SEEMEE R300, then you are sure to have come across a few negative ones. Some reviews trash the SEEMEE R300, but I’m skeptical — many seem subjective and lack solid evidence.
My testing is grounded in hard data: video, photos, GPS logs from my Garmin Edge 840 Solar and Forerunner 955 Solar, and graphs from the My Bike Radar Traffic app along with GPS screen recordings from my Garmin Edge 840 Solar and my Garmin Forerunner 955 Solar. Also, I have graphs from the data collected by the radars using the My Bike Radar Traffic app on the Connect IQ store (check out https://www.mybiketraffic.com for more info).
In the following few sections, I break down how the Magicshine SEEMEE R300 Smart Radar Taillight compares to the Garmin Varia. Since the Garmin Varia typically ranks as one of the best cycling radars, it is used here as the baseline that the SEEME R300 is compared to.
The Magicshine SEEMEE R300 can detect up to eight vehicles passing at once, though I haven’t been able to capture this type of event.
Standing Still Car Passing
In this test, I set up the bike next to the road and set up the radars on the bike with the Garmin Edge 840 connected to record the data. Then, in my vehicle, I did four passes at different speeds with another GPS device in my vehicle recording. When I attempted this test, I only had the app on one device and didn’t test the two radars simultaneously. Thus, each radar had four separate passes each.
In the first graph below, you can see the four passes I made in my van. The red line is the speed recorded from the GPS device I had in my vehicle (a Hammerhead Karoo 2). I would start a good distance away and accelerate toward the bike. The red line that increases before the blue lines is me accelerating, and at a certain distance, the radar would begin picking up my speed.
This stationary test isn’t the best gauge — radars are designed for moving bikes, not data storage. I believe they weren’t intended to be on a stationary bike to capture vehicle speeds. Also, I don’t think there was an intention to use these devices to save this data at all.
I believe cycling radars are meant only to send data for graphical display on the GPS unit as a safety aid. Also, I think the My Bike Radar Traffic app pushing the limits of these devices’ capacities, but with good intentions. I don’t think the data is very accurate or reliable. But currently, I can’t tell if it has to do with the app or just the devices.
As you can see from the blue line, the speed recorded by the radar is constant unless there is a large acceleration/deceleration. This probably has to do with the lower frequency wavelength that is used to detect the vehicles. With correctly calibrated radar guns, their accuracy can be within 1 to 2 mph, so with these devices, I expect them to be a bit less accurate.
Also, I am unsure if this radar data, when being saved to the .fit file through the My Bike Radar Traffic app, is being rounded and truncated, hence similar values. Either way, the Magicshine SEEMEE R300 is missing the vehicle speed by quite a bit. It seems to always be underestimating the speed.
In the first graph, the difference seems quite drastic. Below, I have enlarged the portions of when I was passing. With these zoomed-in graphs, the difference doesn’t seem so dramatic. When the deceleration is close by, the SEEMEE R300 does a good job of catching that.
The next graph below is the four passes but using the Garmin Varia radar to detect the speed of my van. It appears that the Garmin Varia has a 7-mph tolerance or bucket. It seems like the speed recorded is the closest speed within that tolerance range. That seems to be why sometimes it overshoots the real value and underestimates it at other instances.
The Varia does a good job detecting the changes in speed and seems to be doing a better job of detecting the speed.
I have zoomed in on the parts of the graph below to get a better picture of the passing data. A few of the times, the Varia is spot on with the vehicle speed detection.
Since the My Bike Radar Traffic app also saves the range data (distance of car from the radar), I was interested in seeing how this data compares to manufacturer claims and between devices. I originally devised these graphs for direct comparison between the devices, but I am introducing them now so we can look at the single car pass, too.
For the following graph, I am comparing Range in meters on the x-axis and the estimated approaching speed of the vehicle. The furthest distance is on the left and zero is on the right. Thus, I have isolated each vehicle (each pass for this test) and plotted them. In the following tests, direct comparisons between initial detection and speed can be directly compared between devices.
For the single car pass test I did, I started each test from the same location, though I wasn’t at a dead stop for each run. Pass 1 and 2 (Car 1 and 2) with the Magicshine SEEMEE R300 have similar range detections, but Pass 4 (Car 4) had earlier, farther detection than all passes and Pass 3 (Car 3) had the latest/closest initial detection.
Examining the GPS data from the Hammerhead device in the vehicle, the initial start point of each run to the location where the bike was set up was approximately 0.1 mile (160 m) away. This helps to confirm my assumptions that initial detection of the radar has to do with the initial vehicle speed (relative vehicle speed) and rate of acceleration of the approaching vehicle.
Most cars won’t be accelerating a lot at initial detection; they are likely to be approaching at a constant speed or slowing down a little before passing. This mainly depends on the type of road that a rider is cycling on. Also, most likely, the relative speed of the approaching vehicle at initial detection is 20 mph or greater.
The following graph is from the Varia. It appears that initial detection of each run is in a tighter group, and detection is typically occurring sooner than with the Magicshine SEEMEE R300. Though, direct comparison cannot be made with this test. As seen in the below graph, the Varia detects the increases in speed during the passing events.
Typical Ride Data
This following section isn’t really a test. This is just typical data that is collected during a ride. I was having trouble parsing the data when multiple cars were passing simultaneously, so the information presented below is only showing instances when a single car is detected.
Once I get my code refined to correctly parse multiple cars, I can update these sections.
The first set of graphs is from a typical ride that I did following a route near my house that I often ride. This dataset is from the Magicshine SEEMEE R300. There is one section of road that is two lanes in each direction, and then I turn off to another one that is a single lane in each direction. The single lane has a few curves and rollers and often detects cars a little later.
The first graph is the raw data record (relative speed of cars) and the second graph is the adjusted speed (relative speed plus bike speed). Once the bike speed is added, the data gets a little bit more refined, but that is only because the speed has a higher accuracy.
For the relative speed, you can easily see how the speeds are binned. Also, another thing to notice is that Magicshine claims that the detection distance is 140 m, but it is picking up cars out to 190 m. The SEEMEE R300 detecting cars further than claimed may be a good thing, because at distances further than 140 m, accuracy is probably severely diminished.
The next set of graphs is from the same route following the same sections of road just described above, but on a different day and with the Garmin Varia collecting data. Though this data isn’t directly comparable, it just gives a good sense of what typical data may look like.
As before, the first graph shows relative speeds of the cars passing and the second is the estimated speed. Similar trends can be noticed as before regarding the binned data.
Multiple Radar Recording
This next section isn’t really a test; it is more of a comparison between the two devices. Since I don’t know what the actual passing vehicle speed is, I can only compare the readings between the two devices. Theoretically, they should be close, but as we saw in the single car standing test, the difference in detection speeds were quite different (I discuss why in the next section).
For this setup, I was using a saddle rail GoPro mount with a twin mount GoPro adapter on it and a GoPro to Garmin mount for the Varia on one side of the twin mount. The Magicshine saddle mount that comes with a quarter-turn adaptor for the SEEMEE R300 taillight was on the other side of the twin mount.
This setup allows me to connect both devices to the bike and it allows me to align each device vertically. Both devices were tested on each side, and no significant difference in performance was detected in either position.
For recording the data, I am using my Garmin Edge 840 Solar and my Forerunner 955 Solar with each device using the My Bike Radar app to record the radar data. I left the watch on my wrist while riding, and I afterwards, I was worried that the GPS speed data collected from the 955 may not be in agreement with the Edge device.
(Coming soon) Here is an in-depth analysis between the datasets that shows they are in good agreement. The devices are generally close in speed and are consistently close. They have a strong linear relationship and track speed changes similarly, and 95% of the differences fall within ± 1 mph.
Statistical Analysis Results:
- Mean Difference (Device 1 – Device 2): -0.14 mph
- Median Difference: 0.02 mph
- Standard Deviation of Differences: 0.81 mph
- Range of Differences: -7.33 to 5.49 mph
- Pearson Correlation Coefficient: 0.9816
- Root Mean Square Error (RMSE): 0.82 mph
- Bland-Altman Mean Difference (Bias): -0.14 mph
- Bland-Altman Limits of Agreement: -1.72 to 1.44 mph
Now that I am confident that the two devices are generally reporting the same rider speed, I am confident in comparing the two devices.
The first set of graphs is the radar detected speed from each device. The second two graphs are the vehicle speeds. It is a lot of data in a single ride, but upon initial inspection, similar trends for certain vehicles can be seen. Again, we see that the detected speeds and total speeds are quite different from each other.
To get a better look at this data, I have separated four cars from the dataset. This data of cars passing was collected on the same section of road described above. Again, this data is a direct comparison between the two devices. Here, it is clear to see that the devices follow similar trends in speed and range detection, but the Magicshine SEEMEE R300 is consistently lower.
The following images are from the ride mentioned in this section. For this vehicle, the Varia detects about 1 second sooner than the Magicshine SEEMEE R300. Even with the curve in the road and a guardrail in the way, the Varia still detected the car. Then, as the car is about to pass, with the front bumper in line with me, the SEEMEE R300 indicates green.
Just as the Varia turns green, the R300’s green indicator cuts off, with the car well ahead of the bike. The Karoo 2 stops indicating green when the car is way down the road (I think this is a function of the computer and not the radar).
The displayed data is better than the data that is written to the .fit file. The Magicshine SEEMEE R300 is showing good information on the computer screen, and it isn’t really being reflected in the written data.
False Positive Detection
Below is a table breaking down the different device decisions. There are two trivial cases: True Negative, and True Positive. These two indications or lack thereof are where the device spends most of the time. The other two are what most people are interested in.
As I have shown above, the device is detecting cars, and from the video snips, it can be seen that it is detecting similarly to the Varia radar. That leaves us with the last two conditions: False Positive, and False Negative.
False Positives are when no car is behind, but the device indicates that there is a car. Typically, this is just annoying. Other reviewers say it is dangerous, but I disagree and elaborate more on this below. See below for a False Positive captured on a ride.
The last one is the critical one and the one that needs to be right. False Negatives are when a car passes with no indication. Fortunately, the device I have received hasn’t given me any of these, though this is hard to prove without constant video evidence. I have seen other reviewers complaining about this, but I haven’t seen any conclusive evidence that the Magicshine SEEMEE R300 gives many False Negatives.
| Device Decision | Actual Situation | |
| Car | No Car | |
| Device Indicates | True Positive | False Positive |
| Device Doesn't Indicate | False Negative | True Negative |
Bluetooth or Bust
Noticing the trend of the binned data got me quite intrigued. I reached out to Brian Toone of My Bike Radar, and he gave me insight into the way that the data is transferred to the head unit via ANT+. Thus, the binned data is an artifact of the ANT+ transmission signal.
Brian also mentioned that the Bluetooth connection is reported to have a higher frequency than the ANT+ transmission. The Edge only saves the data a 1 Hz, which is the standard for .fit files.
Then, as the car is about to pass, with the front bumper in line with me, the SEEMEE R300 indicates green, trying to connect the radar to my phone via Bluetooth to different apps. Cadence has a nice app that displays a lot of passing information. I reached out to the support team, and they quickly responded, but unfortunately, the radar data that shows in the app isn’t included when the activity file is exported.
My Bike Radar doesn’t have an export activity option either, so that doesn’t work either.
Currently, since I have spent too much time trying to dive into this issue, I did a quick run recording with the Varia connected to the Edge 840 and the Varia connected to the Cadence app on my phone via Bluetooth. At the moment, I haven’t figured out a way to record a ride on my phone then extract the data to plot it.
Thus, in the following graph, I have plotted the range vs speed data of a single car passing. This data was manually extracted from the data that was processed on My Bike Radar. From the graph, it is clear to see that, for a post-data processing standpoint, the Bluetooth connection is far superior. It appears that the data isn’t being binned, and it appears to be more realistic to what is actually happening.
As the car approaches, it slows down gradually. This can be seen in the data transmitted via Bluetooth. Interestingly, it is the same data being detected by the device; it is just being delivered via different signals. The Bluetooth signal detects the vehicle sooner (further distance) and records a closer passing distance, in addition to capturing better speed data.
The data binning isn’t going to be noticeable on the GPS screen since the screen refresh rate is higher than 1 Hz. The issue is how the data is down-sampled to 1 Hz for .fit file logging through ANT+. Whereas Bluetooth has a higher bandwidth and sends minimally processed data to be written to the .fit file.
I have concluded that if any meaningful data is to be extracted from cycling radars for comparing radars or analyzing car passing information, no matter the brand, Bluetooth transmission is the only way to get reliable data.
With that said, since the Magicshine SEEMEE R300 device I got didn’t have Bluetooth on it, I can’t make that comparison. Also, that’s why I am showing only a one-car comparison to prove my point using a different radar.
Battery Life Performance
I conducted two battery tests:
- Solid High Mode (Radar On): Lasted 5 hours, switching to Low Power Mode for an additional 2.26 hours (total: 7.26 hours). This is 63% of the claimed 8-hour runtime for Solid High Mode or 91% including Low Power Mode.
- Day Flash Mode (Radar On): Lasted 12.2 hours, with 2.6 hours in Low Power Mode (total: 14.8 hours). This is 75% of the claimed 16.2-hour runtime or 91% including Low Power Mode.
These tests, conducted under ideal conditions, suggest Magicshine’s claims are optimistic. Real-world use may yield shorter runtimes, especially with frequent vehicle detections. For my weekly rides (1–4 hours), the battery life is sufficient, but long-distance cyclists may need a secondary light.
Limitation of this test
Though the radar mode will be on, I won’t be encountering cars during the test. I am unsure if detecting a car vs only sending a signal out drains the battery at different rates, but we can assume my testing method drains it less. Also, separately, when a car approaches, the light begins to flash. So, potentially, encountering a lot of cars could drain the battery more than not encountering many.
To test the light, I am setting up my GoPro on Time Lapse mode at a 10s interval. I don’t want to create a huge file, and I want a continuous shot. The light will be set up a few feet away from the camera so that it can continuously monitor it. Afterwards, I will determine when it cut off, do some conversions, then determine the battery life.
The light will be fully charged prior to each test. A fan is set up and is pointed at both the GoPro and SEEMEE R300 to keep them cool during the testing.
A more rigorous test would involve testing multiple times for each mode, test the brightness output, do some statistics, and with higher confidence of the battery life.
Test 1 – Solid High Mode Radar On
The light was initially on Vibration Mode, so the light cut off after 5 minutes and was on standby for maybe 20 minutes at most before I went back to check on the test. Therefore, I have added that additional time to the full test.
Video 1 showed a cutoff at about 1 second, which comes out to right at 5 minutes or 0.08325 hours of light runtime. The second video was right at 60 seconds long, which is about 300 minutes or 4.995 hours of light runtime. So, total time was right at 5 hours.
The light did not shut off at 5 hours but went into Low Power Mode. On Low Power Mode, the light stayed on for another 136 minutes or 2.26 hours.
Thus, technically, the total runtime of the Magicshine SEEMEE R300 in the Solid High Mode is 7.26 hours. This falls short of the claimed 8-hour runtime and slightly disingenuous since the solid mode was only on for 5 hours. That makes the actual runtime only about 63% of the claimed runtime if only the Solid Mode is considered and 91% if the Low Power Mode time is included.
Test 2 – Day Flash Radar On
Analyzing the video of the Magicshine SEEMEE R300 in the Day Flash Mode with the radar on, it stayed on for 734 minutes or 12.2 hours before switching to Low Power Mode. In Low Power Mode, the light stayed on for an additional 153 minutes or 2.6 hours.
The total time the light was on was 14.8 hours, which is quite short of the 16.2 claimed hours runtime. Considering the Day Flash only, it was about 75% of the claimed life, but considering the total time on, it was about 91% of the claimed life.
This was only two tests in ideal conditions, and real world conditions will most likely be less. Even though 12 hours of battery life in the light mode I prefer to use is pretty good, it is far below the claimed values. Based on my device, I feel confident claiming that the posted values don’t match, and this could be due to me receiving a preproduction device.
Things I Would Change
It is tough to say what I would change, since the model I have is a pre-production model and doesn’t have everything that the final version has. The SEEMEE R300 offered now by Magicshine connects to the app. The connectivity allows you to change light modes and set up some custom light settings.
Unfortunately, with this model, it won’t connect to the Magicshine app, so I cannot test out those features.
I saw another reviewer making claims that, from the units he was testing, the battery life was way off. The few tests that I ran showed that the battery drain was a lot quicker than the ones claimed. Technically, the solid run was close, but I think including the Low Power Mode is a bit dishonest and should be better clarified.
I am not sure if better firmware could improve the battery life, but that should be a focus to improve the device. Maybe adding a bigger battery would help achieve the claimed battery life.
I think the biggest flaw with the device is the number of false positives it gets. This needs to be worked out to reduce the number. I don’t know if this is just a firmware fix, a setting adjustment in the app, or just inferior radar sensor technology.
Apart from the buggy radar, I think it is a good light with good brightness and provides a lot of visibility. I think it is a pretty durable light, and it works pretty well in wet conditions. Even when the radar was covered in sand, it was still working fine.
Final Thoughts
Apparently, there are quite a few reviews available that are slamming this device. It appears that this device has been in the works for a while, with some reviewers getting earlier versions, and later receiving updated versions. The version I received was at the end of 2024 and was preproduction model.
I cannot make claims or verifications on the reviews stating that their devices weren’t faulty or not fully developed, but though my device isn’t perfect and, compared to a Varia, isn’t quite as good, it has been far from a “disaster”, “shameful”, or “should be avoided.
Magicshine is receiving a lot of negative reviews on this product, and it is partly their own fault. If the product wasn’t fully finished, they should have delayed the release and addressed reviewer concerns.
I have seen quite a few reviews online of people with their bikes parked on the side of the road and making claims of the radar missing cars or not detecting them. Though I did test this way also, this is not the design intent of the device. The device is detecting relative speeds and was designed with a rider in motion.
Thus, making any claims about the device’s performance with the bike parked are irrelevant.
At no point while using this device, have I had any false negatives, at least none that were so egregious that I clearly knew it wasn’t indicating a vehicle. My device detects cyclists, motorcycles, and vehicles consistently.
And without continuous video evidence and some way to back-check the video with the radar data to see if it detected every vehicle that has passed, it is impossible to tell if it does pick up every vehicle. This is especially true when multiple vehicles are passing at once. This goes for every device.
Unfortunately, this device isn’t perfect, and it does give false positives. One thing I’ve noticed is that it is typically consistent in when it gives false positives. There is a location, a metal pavilion, that I pass by, and when I get about 100 ft away or so, it gives a false positive. So, it is detecting something; it just isn’t a car.
I have also noticed that, typically, most of the false positives are in neighborhood streets, or on bike paths with tree coverage. When a false positive is triggered, the object indication symbol on the bike computer typically starts at the middle or higher up, then quickly cuts off.
I’m not sure if this is just a sensitivity setting in the detection, the radar sensors themselves, something in the programming of the device, or a combination of those things. At worst, these false positives are annoying. Therefore, typically, with a false positive, when you look down at your computer, you know it is one right away.
When the device does detect an actual car, the vehicle indication starts at the bottom, then moves its way up as it approaches the rider.
In a perfect world, these devices would work perfectly. To say the Garmin Varia works perfectly 100% of the time would be a lie. I have had false positives with it, and it appears that since the latest firmware update, they have been occurring more often (not as often as the R300).
Relying on these radar devices alone for your safety is not the intention of these devices. They are designed to improve your situational awareness, not replace it. Attentiveness and good judgment are still required. Just because your radar isn’t indicating a car, doesn’t mean you don’t need to look behind you.
So, if a rider isn’t looking and relies only on this device, it has the potential to be dangerous, but this is no fault of the device. It is because the rider isn’t paying attention.
Thus, if a rider doesn’t have a radar device, are they in less danger than a rider with a radar device with a false positive rate of less than 100%. Yes, but only if the rider with the radar device uses it as a crutch or replacement for checking their surroundings.
At no point have I felt unsafe with the device, and one isn’t safer, per se, with or without the device. Considering my experience with the device, those that are claiming that this device is actually harmful are looking for clicks and reactions. Safety is incumbent on the cyclist always being fully attentive to their surroundings and situations.
This device isn’t a crutch; it is only meant to give you an advance warning of approaching vehicles.
Would I recommend this device? If your budget is tight, yes. Get a radar. Having a radar has given me a little more security while riding on the road. And it is great to know when a car is approaching.
Currently, this pre-production model leaves a bit to be desired, mainly the battery life claims and the missing Bluetooth. I think, once Magicshine gets a few things worked out in the firmware, they could have a device that is on par with the Garmin Varia. If you have the means and can afford the extra cost, the Garmin Varia is still the leading radar on the market.
Author Conflicts
The SEEMEE R300 was provided to me by Magicshine. I did not receive any compensation to review this product. Magicshine was not involved in reviewing this article (before or after), but was available to answer any of my questions. This product was reviewed in an unbiassed manner to provide information about the product and hopefully give readers useful information to help guide their decision in purchasing this product.
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