BioLite HeadLamp 425 review: The best astronomy headlamp?

The BioLite HeadLamp 425, for our money, is one of the best headlamps you can buy. If you've seen our best headlamps for astrophotography and low light scenes buying guide previously, you'll have seen the BioLite 330 on the list. Well, the BioLite HeadLamp 425 is its younger sibling, released at the end of September 2022. 

BioLite actually had a complete refresh of their award-winning rechargeable headlamps, with three new models on the market: the HeadLamp 325, the HeadLamp 425 and the HeadLamp 800 PRO.

As stargazers, the HeadLamp 425 piqued our interest above the other models due to the red flood light, the glove-friendly power button, and the 'run forever' battery. We will discuss these and other improvements later.

In addition to the above astro-friendly elements and enhancements over the prior BioLite models (which we loved), the new versions offer increased beam distance, better run time and improved temperature use rating.

We also think it's important to highlight BioLite's mission to empower people and protect the planet through renewable energy. It's a bold mission to provide 20 million people with access to clean energy and avoid 3 million tons of CO2 emissions by 2025. But it seems that by purchasing a BioLite product, you're helping with that mission.

BioLite HeadLamp 425 review

BioLite 440: Design

• Integrated rear red flood and strobe
• Glove-friendly button
• Weight sits at the back of your head

A lot of thought has gone into the design of this headlamp, with some notable changes from existing models, to some tiny changes but with big advantages.

As with the other BioLite HeadLamps the battery pack sits at the back of your head which means that is where the weight sits. The profile on your forehead is a mere 10mm so it doesn't feel big or bulky. While primarily a design feature for runners, it adds comfort for any wearer. What's more, BioLite has cleverly integrated a rear red flood and strobe into the back of the headband, maximizing the functionality. Even though the main front lamp has a red mode, astrophotographers may prefer to only use the rear one by spinning it round to the front of the head, so there is absolutely no risk of turning on the white, night vision-ruining LED lamp.

If you weren't looking specifically for it, you probably wouldn't notice that the power/mode button has been improved from previous versions to make it more glove friendly. One of our least favorite things about the BioLite 330 was the tiny power button which was partly obscured by the casing. While the new button doesn't look hugely different, the extra profile that protrudes past the casing is actually very helpful for use with gloves or cold fingers, something we stargazers often experience.

As the battery sits at the back of the headband, the power is fed to it via a spiral cable. It's very neat, but as someone with long curly hair, it did get tangled a few times. This is only a niggle though, and we are only (pardon the pun), splitting hairs.

The only other downside we can think of with the battery (and integrated light) being at the back, is that you couldn't lie down — say when reading a book — but that doesn't bother us as skywatchers.

It would be advantageous if this headlamp was fully waterproof, like the Knog Bilby we reviewed, although with a rating of IPX4, it is protected from splashing water from any direction so it will be fine in a rain shower.

You can purchase the BioLite in three different color designs, Ocean Teal (featured in this review), Midnight Gray or Ember Yellow.

BioLite 330: Performance

• 60 hours on a single charge (on low)
• Very comfortable
• Covered by a one-year warranty

We have already discussed the battery sitting at the back of your head, rather than weighing down your forehead. But for more comfort, the BioLite HeadLamp 425 uses a 'no bounce' moisture-wicking headband, keeping sweat off your face and keeping the band fresher for longer. It can be washed with mild soap when necessary.

Though we aren't using this headlamp for running purposes in this review — runners are the target audience for this design — we have been on many brisk walks in the dark. On each occasion, the headlamp feels secure on our head and it really is easy to forget you have it on.

When used as a standard white LED headlamp, the beam distance on full power is an impressive 85 meters, or 15 when on low power. Full power burn time is four hours, and a whopping 60 hours on low power. There are seven lighting modes in total: White Spot, White Strobe, Red Flood, Red Strobe, Spot+Flood, Rear Red Flood and Rear Red Strobe.

The bulb on the front of the headband tilts to four different positions, so it can be manually adjusted to suit what you need it for, whether that be seeing far into the distance straight ahead or on a lower power looking down, making adjustments to a tripod, for example.

Should you encounter any problems with your BioLite HeadLamp 425, you are covered by the one-year warranty; make sure you register after purchase (it takes less than a minute).

BioLite 330: Functionality

• USB-C rechargeable
• LED Battery indicator
• 'Run Forever' charging

There is more than one way of ensuring you aren't caught out and left in the dark. The first is the LED Battery indicator. It turns on for seven seconds when you turn the headlamp on (or when you turn the rear red flood) and again when you turn it off, which serves as a nice reminder to plug it in after use, if necessary. The other way is 'reserve mode', which alerts you (by flashing) when the battery is running low and provides an hour of backup light. 

Another neat feature is 'pass-through charging,' which means you can plug it into an external power source while in use. We are especially pleased to see that BioLite has moved away from micro-USB charging to the more universal USB-C. Hurrah, no need for multiple power cables to charge up different devices! It takes approximately two hours to recharge from empty to fully charged.

As we've come to expect from headlamps, having reviewed many of them, there is a 'lock' function, so you don't accidentally turn it on and waste power in transit. Hold the power button down for eight seconds. Then the same to unlock it.

The temperature rating, for those extreme weather stargazers, will be glad to hear that it is rated -20C to 60C (-4F to 140F). There's no need to worry about it being too cold or hot to function.

Should you buy the BioLite HeadLamp 425?

Simply, if you're looking for a good all-rounder headlamp with handy astro-friendly features, you should seriously consider the BioLite HeadLamp 425. It is excellent value for money and we can't think of a way to make it any more functional, especially at its very reasonable price point. 

It is comfortable and practical and offers astronomers and skywatchers a convenient means of being hands-free while observing the night sky or in between taking astrophotographs.

If the BioLite HeadLamp 425 isn’t for you

We've tested and reviewed several headlamps, and with the models that sit at a similar price point, it's primarily down to personal preference as to which one you choose.

The BioLite HeadLamp 425 can easily be compared to the Petzl ACTIK CORE 450 which we reviewed in terms of lumen output, single press operation, manual tilt and an LED battery indicator, but it has the advantage of the rear red flood and strobe.

After our Knog Bilby 400 review we found another firm favorite and is a unique-looking, fully waterproof alternative. It is highly customizable, and the lamp itself can be removed from the silicone casing and plugged directly into a USB power source, negating the need for cables.

Check out our best headlamps to see other headlamp recommendations from us, which we have selected especially for skywatchers.