march.brown
Flashlight Enthusiast
Just been reading the write-up on a cheap 3 Watt CR123 LED torch that says it has a runtime of two hours and is 80 lumens.
The CR123 primary cells that I have been looking at seem to be about 1300 or 1400 mAh capacity and 3.0 Volts ... If the output of the torch (or the battery consumption) is 3 Watts , then the current would be one amp at 3 volts ... But the battery is only say 1400mAh ... To run at one amp for two hours , the capacity would need to be 2000mAh ... To run for two hours on a 1400mAh battery , the current would only have to be 700mA ... So what gives ?
Is there another factor in the equation ? ... Or do they rely on the gradual decay of the voltage enabling the torch to gradually get less bright and thereby last for two hours ... Finally just being too dull to be of any use.
I can't see torches of this price range having a means of boosting the battery voltage to keep the brightness fairly uniform.
Any explanations please or is it poetic license (terminalogical inexactitude) on the sellers behalf ?
.
The CR123 primary cells that I have been looking at seem to be about 1300 or 1400 mAh capacity and 3.0 Volts ... If the output of the torch (or the battery consumption) is 3 Watts , then the current would be one amp at 3 volts ... But the battery is only say 1400mAh ... To run at one amp for two hours , the capacity would need to be 2000mAh ... To run for two hours on a 1400mAh battery , the current would only have to be 700mA ... So what gives ?
Is there another factor in the equation ? ... Or do they rely on the gradual decay of the voltage enabling the torch to gradually get less bright and thereby last for two hours ... Finally just being too dull to be of any use.
I can't see torches of this price range having a means of boosting the battery voltage to keep the brightness fairly uniform.
Any explanations please or is it poetic license (terminalogical inexactitude) on the sellers behalf ?
.
