I have some of those 1000 lumen Duracell-branded LED flashlights that Costco sells.
They eat batteries like there's no tomorrow.. so I got me some Eneloop NiMH batteries and installed them.
Turned on the flashlight. Got one bright flash for a millisecond and then no output. Upon closer inspection, I see the LED chip glowing about the same brightness as those old phosphor dial wristwatches. Thinking it was a battery problem, I put the old alkaline batteries back in and the flashlight still wouldn't work.
In the past, I've run LEDs on benchtop power supplies without a current limit resistor, observing that once you exceed a certain amount of current, the LED is irrecoverably ruined and will only glow dimly after that.
I'm wondering if the Duracell LED flashlights lack proper current limiting and rely on the saggy nature of alkaline batteries to limit current below the destructive level? Obviously, the NiMH can deliver a lot more current and although slightly lower voltage than fresh alkaline batteries, they won't sag as much under load.
Be careful with trying rechargeable batteries with these LED flashlights!
They eat batteries like there's no tomorrow.. so I got me some Eneloop NiMH batteries and installed them.
Turned on the flashlight. Got one bright flash for a millisecond and then no output. Upon closer inspection, I see the LED chip glowing about the same brightness as those old phosphor dial wristwatches. Thinking it was a battery problem, I put the old alkaline batteries back in and the flashlight still wouldn't work.
In the past, I've run LEDs on benchtop power supplies without a current limit resistor, observing that once you exceed a certain amount of current, the LED is irrecoverably ruined and will only glow dimly after that.
I'm wondering if the Duracell LED flashlights lack proper current limiting and rely on the saggy nature of alkaline batteries to limit current below the destructive level? Obviously, the NiMH can deliver a lot more current and although slightly lower voltage than fresh alkaline batteries, they won't sag as much under load.
Be careful with trying rechargeable batteries with these LED flashlights!