Black Diamond Cosmo (2026, 350 lumens)

How much light it gives at full power, for finding your way in the dark. 5: Does the job. Average for wild-camping gear.

Maker's figure, 350 lumens with no test standard stated on Black Diamond's product pages: the 300–499 band (maker's figure). Its instruction sheet gives 3.2 hours at this level on three AAA and 5 hours on the BD 1500 pack.

How long one charge or set of batteries lasts at a level you can walk and cook by. 7: Better than most.

Black Diamond's instruction sheet (linked from its product page) gives 6 hours on Medium (175 lumens) with three AAA and 9.4 hours with the BD 1500 pack (sold separately): both are the 6–9.9 h band, so it is in the 4 band either way. High (350 lumens) lasts 3.2 hours on AAA. The product pages show only 200 hours, which is the 6-lumen Low mode.

How much it adds to your pack and your head. 7: Better than most.

Black Diamond's product pages (US and EU) list 88 g and its instruction sheet gives 75 g with three AAA (a 42 g lamp plus 33 g of batteries): both in the 50–89 g band. Ultralight Outdoor Gear gives 89 g 'without batteries' and Needle Sports 88 g including them, so the shops disagree on what 88 g covers, but the instruction sheet shows the bare lamp is 42 g, so 88 g can't be the bare lamp.