Reviewed by Kings350 - 22nd Jan, 2019 Great brghtness, doesn't last - dims after 2 mins I had such high hopes for this headtorch - 600 lumens & rechargeable battery (I hate to think how many AAA's I've used in my old headtorch). I charged the battery fully prior to its first outing. I started to notice the light gradually dimming as I was using the torch, at 1st I thought it was my eyes accustoming to the brightness. It wasn't my eyes! I turned off and back on again and it went back to full power for 2-3 mins before dimming again. Is it a safety mode to stop the lamp overheating?? No it isn't as it still dims when the lamp is on the lowest brightness setting. I tried recharging the battery but it made no difference. I returned it for a refund as the store didn't have another to exchange.