BioLite  HeadLamp 425

There has been considerable discussion on what the actual runtime is on the BioLite 425, including some reports of very short runtimes of less than 30 minutes. The manufacturer claims 4 hours of battery life on “high”. Earlier this week I received two lamps (one for me, one for the wife) and thought I would run them through a battery life test. I stopped the clock when the light became noticeably dim – to the point it no longer functioned well. I found that you had about ten minutes after it started warning you that the batter was low (it flickers three times) before it went into the super dim mode. I’m guessing this is what BioLite calls the “reserve” mode. The spot mode is quite bright. Very easy to do a trail run at night. The flood setting is bright enough to walk with but doesn’t cast enough light to run by. Still, it provides enough light to read by or make dinner at a campsite. Flood only: Lamp A: 4 hours 20 minutes Lamp B: 5 hours* Spot only: Lamp A 4 hours 25 minutes Lamp B 5 hours 25 minutes* Flood & spot: Lamp A 4 hours 10 minutes Lamp B 4 hours 1 minute *For some reason, Lamp B was somewhat dimmer than Lamp A over the duration of these two tests. Not surprisingly, it was able to last longer since it was drawing less current. Overall, pretty solid results. If you are getting noticeably shorter runtimes, you likely have a defective unit. I didn’t check how dim you would have to reduce the brightness to get to the 60 hour mark, but the lamps are bright enough in spot mode to dial back the setting some. I could see 8 hours as very doable. I was a little surprised that the flood and spot together lasted almost as long as each individually. I think the power to each is reduced a little when operating both lamps together. All-in-all, I like this headlamp. No new electronics should be brought to the market in 2023 utilizing micro USB, so I was glad BioLite added USB C to this model at least. Love the rear red lamps. There are two in the back and only one on the front. So if you are doing some night photography or astronomy, you might want to spin the headlamp around and use the two red lamps on the back. Note the red lamps are “flood” and not a “spot” lamp.

The specs on this headlamp looked like exactly what I wanted for night hiking. However, I really only hike in the dark in winter, and the battery life right around freezing was not adequate for a less than 2 hour hike at that temperature, and not even at full brightness. While it can run from an external pack on the USB cable, I decided I’d rather have a bigger battery in the light. I emailed BioLite but they could not give me run times at different temperatures. Since this is critical in outdoor gear, I will not be trying another headlamp with a rechargeable battery where they don’t specify temperature performance. I’ll go as far to say it’s irresponsible to not specify this. Non-rechargeable lithium batteries are excellent in the cold, and light weight but expensive. I’d hoped rechargeables had improved more. PLEASE give me the specs so I’m not guessing when I purchase! If REI required this info to sell products it might help reduce returns.