Originally Posted by
SylvainG
The light you mention has a T6 LED, which at 2 amps produces a max of 692 lumens according to this
Datasheet, so close to the 800 lumens you mentioned, but the light's description says its 5.2Ah power pack lasts 3 hours so drains it 1.73 Amps. At 1.5 Amps, the light gives out 551 lumens. With a bit of maths, at 1.73 Amps, the lumens is about 615 (half the specified lumens by the seller). Still pretty good for a $18 lights.
Looking a lights from a site posted in another subforum, stumbled upon this one which is pretty similar to that Amazon light:
We Test Lights | Bright Eyes 1200 Lumen Test and Review
The site tests the claimed lumen against reality. So its 1200 lumens was actually... 353 lumens! That's a 847 lumens difference! Yikes!