This chunky torch from Electron has a measured beam and is built to last, but the lack of side visibility and short run time mark it down as a standalone commuting option, and there are cheaper lights available if you just want a bright torch.
The Nano 9 is certainly a well-built light with an Aluminium body and chunky rubber button on the base that's easy to use with your gloves on. Pop the 4 AAA batteries (supplied) in and switch the light on and you get a bright, measured beam. Multiple LED torches – the Nano uses nine, obviously – tend to give out a softer light and the Electron is no exception. It's not as focused as others we've tried but it throws out a good pool of bluish-white light and it's enough to see by on a dark lane if you take a bit of care.
Seeing is okay but being seen isn't quite as well covered: the Electron has no side visibility at all. Given that the light is specifically designed as a bike unit and being seen coming out of junctions is a big safety issue – not to mention a legal requirement in the UK – it's a fairly big oversight. What it means is that to keep safe you'll be wanting to supplement the Nano 9 with a cheap LED to improve your visibility.
Run time is the other main concern. Stated run time is 'up to 70 hours' but ours only lasted about 10 on its supplied batteries before needing new ones. You'll want to fill it with rechargeables to save yourself a big energy bill. It'd last a lot longer in flashing mode but it's not really the kind of light you want flashing.
Overall it's worth looking at if you need to kick out a bit more light than a cheap LED unit for the dark bits of your ride, it's good as a supplementary light. It's effectively just a torch though, and though the quick release mount is a lot better constructed than the ones you get with LED torches from websites like www.dealextreme.com, those lights are a lot brighter. and quite a bit cheaper.