Guide · Lights
Bike light runtime: maker claims, ANSI FL 1 and what reviewers recorded
A bike light's runtime belongs to one mode and, under FL 1, ends at 10 percent of starting output. How to read maker ratings and what reviewers recorded.
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Short answer
A bike light's runtime belongs to one mode. Under ANSI/PLATO FL 1, it runs from the output 30 seconds after switch-on until output falls to 10 percent of that value, so it is not time at full brightness.[1] Read the runtime for the mode you will ride in, and leave a margin.
What a runtime figure measures
Under ANSI/PLATO FL 1, runtime is measured from the output 30 seconds after switch-on until output falls to 10 percent of that value.[1] The test starts with fresh batteries. A light can spend much of that time well below its starting brightness and still be inside its rated runtime.
Following FL 1 is voluntary, and each company runs its own tests.[1] A bike-light maker's page may not say which method it used. Treat every runtime on a box as the maker's rating, tied to one mode, unless a named reviewer recorded something else.
Maker ratings, mode by mode
These are the makers' own ratings, not measurements:
| Light | Shorter-running mode (maker rating) | Longer-running mode (maker rating) | Battery (maker) |
|---|---|---|---|
| Magicshine EVO 1700 | 1,700 lm for 2 h, high beam | 200 lm for 11 h, lowest low beam | 4,000 mAh, USB-C |
| CatEye AMPP200 | 200 lm for about 1.5 h, high | 40 lm for about 13 h, low | 3.7 V, 800 mAh |
| Knog Blinder 1400 | 1,350 lm for 1.5 h, High Steady | 230 lm for 8 h, Low Steady | 5,000 mAh |
| Garmin Varia RTL515 (rear) | 20 lm for up to 6 h, solid | 65 lm for up to 16 h, day flash | Not listed here |
Sources: Magicshine,[2] CatEye,[3] Knog[4] and Garmin.[5]
Ravemen describes the CR1000 as running from a 4,000 mAh 3.6 V lithium-ion battery.[6] Its page also lists a 45-hour maximum runtime without tying it to a mode, so that figure cannot be matched to any brightness level. Ravemen adds that runtime can be extended by connecting an external power source.
Notice the spread within one light. The EVO 1700's rated runtime runs from 2 hours to 11 hours depending on the mode, and the RTL515's from 6 to 16 hours. In these examples, the longest figure belongs to a low or flashing mode.
Picks that fit3 products
Front: Knog Blinder 1400, light only; Knog rates 1.5 h in High Steady and 8 h in Low Steady.
More on choosing
Or the Magicshine EVO 1300 (not the EVO 1700) under an out-front mount; Magicshine rates 2 h in Turbo and 3, 6 or 15 h on its three low-beam levels. Rear: Garmin Varia RTL515 (010-02376-00), not the RTL516, which has different ratings; Garmin rates up to 6 h solid and up to 16 h in day flash. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or the brand.
Front light with runtime by steady mode
Under-bar front light with runtime by beam mode
Magicshine EVO 1300 under-mount front light (cut-off low beam, USB-C)
Rear radar tail light with runtime by mode
What a reviewer recorded on the road
Ride reports rarely match a lab protocol, but they show what a real mix of modes does. A road.cc reviewer got about two hours on full power plus about 30 minutes on dipped beam from the Magicshine EVO 1700, after which the light shut off with no reduced limp-home mode.[7] That is one mixed-mode ride, not a controlled curve and not 150 minutes at constant maximum. The same reviewer reports a full charge from flat at 2 A took about 2.5 hours.
The useful lesson is the shutoff: on that ride the light went dark rather than dropping to a reserve mode. Check your light's manual for how it behaves when the battery is nearly flat.
Two lessons from a flashlight test
1Lumen, a flashlight review site, publishes runtime graphs that make the method visible. These results are for the Olight GOTORCH X flashlight, not a bike light, and the reviewer received the sample free from Olight.
- Runtime is not time to shutoff. In low mode, the GOTORCH X reached its ANSI-style runtime endpoint at 7 h 29 min but kept running until 10 h 44 min before shutting off.[8] Its time to shutoff was more than three hours longer than its runtime.
- Cooling changes the result. In high mode, the same flashlight reached the endpoint at 4 h 43 min with fan cooling but at 13 h 29 min without a fan.[8] The longer figure without the fan reflects output stepping down, not more light.
We found no bike-light test that shows how riding speed or cold air changes runtime. Do not assume your light behaves like this flashlight.
Thermal step-down
Some lights lower their output on their own when they get hot, which is often called thermal step-down. We could not confirm any bike-light maker's statement on this, so we name no light that does it. Your light's manual is the place to check.
Plan your ride around the mode
- Write down your longest regular ride in darkness.
- Find the maker's runtime for the mode you will actually use, not the "up to" figure.
- Leave a margin, because FL 1 runtime ends at 10 percent of starting output.[1]
- Check the charge time from the maker. CatEye gives about 2.5 hours at 0.5 A for the AMPP200,[3] and Knog lists a 5-hour charge for the Blinder 1400 with no cable in the box.[4]
Next
Questions
How long do bike light batteries last?
It depends on the mode. Knog, for example, rates the Blinder 1400 at 1.5 hours in High Steady and 8 hours in Low Steady, so read the runtime for the mode you plan to ride in.[4]
Why does my light dim before the stated runtime is up?
Under ANSI/PLATO FL 1, runtime runs from the output 30 seconds after switch-on until output falls to 10 percent of that value. A rated runtime is not time at full brightness, so a light can dim well before it reaches the number on the box.[1]
What does ANSI FL 1 runtime mean?
It is the time from the 30-second output reading until output drops to 10 percent of it, starting with fresh batteries. Following FL 1 is voluntary and each company runs its own tests.[1]
Does a light run longer in the cold or when I'm moving?
We found no bike-light test on this. In one flashlight test by 1Lumen, cooling changed the high-mode result a great deal, so conditions matter, but that result is for that flashlight only.[8]
Will my light keep a low glow when the battery is nearly flat?
Not always. A road.cc reviewer reported that the Magicshine EVO 1700 shut off after its run with no reduced limp-home mode. Check the maker's manual for your light.[7]