The Best Way to Carry Battery Packs for Mountain Bike Lights

Whether you’re taking part in an overnight race, staying out on the trail a little longer or going for a quick night ride with friends, you need lights. The best mountain bike lights are powerful enough to illuminate technical terrain at speed, so they tend to have large external battery packs for extended run times at maximum brightness. Some battery packs are designed to strap straight to your frame, but you can make life easier with a frame bag, keeping your battery pack dry and clean and making space for other spares and night-riding essentials.

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A mountain biker in the night, with a front light pointing toward the camera


What Are the Best Lights for Mountain Biking?

Compared to road riding, you want a powerful beam that lights obstacles at multiple heights. Trails are twisty and sometimes overgrown, so the light needs to help you see and react to obstacles as far ahead as possible.

If you need to ride roads or shared paths to reach your trails, you also want something that can be dimmed to not blind oncoming traffic. Usually, you’ll want a helmet light alongside a light attached to the bars. This lights where you’re looking, making it easier to check corners are safe before turning.

Most riders will use a high-powered light on the handlebars for general illumination, alongside a secondary light on their helmet. The handlebar lights are usually bigger and heavier, with large battery packs, while helmet lights are lightweight to avoid neck fatigue. Helmet lights also tend to be ‘spots’, providing highly directional, concentrated light where you’re focusing.

A rider removes a jacket from a Backcountry Frame Pack (1L)

How to Mount Mountain Bike Lights for Night Riding

Lights should be mounted to your handlebars, preferably as centrally as possible and secured tightly, following the manufacturer’s guidelines. Unlike most road lights, some mountain bike lights can be mounted above or below the bar – just be careful to check it’s waterproof in the orientation you want to use it. You might also want to consider how you route your mountain bike cables to ensure your light is unobstructed and that the battery power pack cable doesn’t get caught on other cables.

Helmet-mounted lights typically come with a strap or attachment system that can be positioned centrally on your helmet. Before you ride, check that the light lines up with where you are looking. Some long-lasting helmet lights will come with a battery pack. Occasionally this will be mounted to the rear of your helmet, other times it will come with a long lead so you can mount it in a jersey pocket or hip pack.

A rider threads the power cable of an Exposure Lights battery pack through the cable port of a Backcountry Frame Pack (1L)

A rider places an Exposure Lights battery pack inside a Backcountry Frame Pack (1L)

Keeping Batteries Dry and Clean

Advances in technology mean even relatively entry-level lights are extremely powerful. However, high power beams tend to last just an hour or two at most, even for the most premium lights. Some lights rely solely on an external battery pack to generate long run times, while others will have an internal battery with an optional external pack. These battery packs are sometimes designed to strap straight to your frame but they can be awkward to mount and can get filthy in the wet/muddy conditions commonly found on the longest nights of the year.

The best solution is to place the battery pack in a waterproof frame bag. Sealed from the elements, there’s no need to worry about trying to clean a battery and no fear of water ingress. Space for frame bags can be limited on mountain bikes, particularly if you have rear suspension, which is where the compact Backcountry Frame Pack excels – fitting even dual-suspension mountain bikes and featuring a reversible design to suit a wide range of frame geometries (with a protected cable port at either end to keep your batteries completely dry). Keeping heavy batteries low and central in the frame ensures you’ll not experience any knee rub and keeps things secure and quiet. The Backcountry Frame Pack (1L) even features lash tabs to secure the battery and prevent excess wear on cables and other items in the pack.

What Else to Carry for Night Riding

An added benefit of attaching a frame pack for your mountain bike battery pack is the extra space it provides for carrying gear. Night rides aren’t massively different from day rides, but it can be useful to check your spares – there’s nothing worse than getting cold or stuck in the middle of nowhere in the dark. Even in the summer, temperatures can drop quickly at night. It’s worth carrying a buff, some arm warmers or a lightweight windproof top for emergencies. It’s also always worth having an emergency snack or two just in case your ride takes longer than you expect – you’re unlikely to stumble upon an open store in the middle of the night!