It’s generally not worth trying to save money by buying the cheapest lights. A good light will cost good money but it will be worth the investment.
Battery powered LED lights lead the market and generally provide good value for money, adequate battery run time and sufficient brightness. For utility cycling, I recommend single unit lights, i.e. lights where the battery and the lamp are housed in the same case, rather than the type with a separate battery and a connector.
Some lights are sold with a separate battery, which occupies a bottle cage, and a connecting cable; the disadvantages of this design are that you have to carry both the battery and the lamp when you leave your bike and you can’t put a water bottle in the bottle cage!
Things to look for in a battery-powered light:
- well built so it survives being dropped by accident
- a recessed on-off button so it doesn’t turn on in your bag
- takes standard batteries, such as AA cells, so you can easily get replacements if they run out
- sufficiently bright
- a fixing bracket that stays on the bike, so you don’t need to adjust the beam height every time you fit the light
It is difficult to make judgments about build quality or brightness from photos online. This means the place to buy lights is a bike shop.
How much should you spend?
Which batteries and charger?
Battery-powered lights ideally need at least two sets of high capacity (rechargeable) batteries and an intelligent charger. A set of good batteries (minimum 2500mAh recommended) and an intelligent charger costs about £60 but they make life easier because they extend the amount of time between battery charges. Unlike a conventional charger, an intelligent charger steps down the current to a maintenance charge when it senses a full charged, meaning you can keep the spare set in the charger all the time.
Of the inexpensive rechargeable battery brands, I have found Energizer age better than Uniross. My Energizer cells still deliver their rated capacity after a couple of years.
There’s more on charging Ni-MH batteries here.
Upgrade tungsten bulbs with LED bulbs
Since the 1990s, the insides of bike lights have become much more sophisticated, with the evolution of LED technology making modern lights far brighter than old ones. However, with entry level lights, the outsides of bike lamps are often poor quality, with cases and brackets made of thin plastic that is easily broken or switches that are prone to failure.
An alternative to buying a new light is to upgrade an old one using an LED replacement bulb. When used in traditional style lamps from the 1980s and 1990s with good build quality and large reflectors and which take larger batteries, you combine the best of old and new, which can be a very cost-effective solution for utility cycling. Buy from a reputable, local seller.
The Torch Site is a established seller in the UK. Their webpage for LED upgrade bulbs is here.
Take your lights with you when you park
For urban transport cycling, do not leave removable lights attached to the bike in a public place. If they are tampered with or stolen, you won’t be able to use them to get home! Modern battery lights are quick release, so it’s very easy to remove and refit them.
A comprehensive test of cycle headlights was carried out in 2008 and the results posted at YACF. The results show beam pattern and brightness.