Gemini Duo 4 Cell bike light review

Tunable, reliable lamp

Our rating 
4.0 out of 5 star rating 4.0
GBP £175.00 RRP | AUD $279.95 | USD $259.95

Our review

Impressively focused power, reliability and extensive tuning in a tiny, well priced package.
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This review is a small part of our Best Mountain Bike Lights feature, where we tell you the three best lights – plus eight others to consider – after testing 24 different sets of lights.


The Gemini’s tiny twin LED headunit delivers 1,500 lumens of punchy long-distance light and enough peripheral to work adequately when it’s mounted on your bars.

As well as the O-ring bar mount it comes with a helmet mount and headstrap harness.

The three power levels are at 20 / 60 / 100 percent output as default with a clear click from the rubber button making it fine to use even with cold, gloved fingers. You can program the different light levels – even the flashing mode – in 10 percent increments if the preset menu doesn’t suit you though.

There’s no battery run-time indicator aside from a low power warning, but run time is long enough for that to rarely be a problem.

The four-cell battery bag is compact enough to fit easily and securely on the frame or longer stems, and if you want even smaller bulk and are happy cruising on a lower light setting there’s also a (slightly cheaper) two-cell battery version.

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Russell Burton

The light output gives great long-distance vision, and decent peripheral too


While you can get more power for less from direct-buy ‘Chinese lanterns’, reliability on every Gemini light we’ve ever used has been excellent and they’re better priced than similarly versatile and tunable units.

Product Specifications


Name Duo 4 Cell (14)
Brand Gemini

Description Run time 3 hours 15 minutes : LED Two Cree XM-L U2 : Battery Samsung 5200mAh Li-Ion : Mounts - Bar, helmet (tested)
Weight (g) 279