There's another problem with the new multiple-die LEDs: heat. When the new Cree and Seoul chips became available, we got twice the light output without any increase in power dissipation (heat generation). But with these devices, the dissipation is multiplied by the same factor as the light output, since they're no more efficient than a single chip LED. It's hard enough to keep a single 3W LED cool enough in a flashlight, and it gets a lot harder as the power dissipation increases. The thermal path from the LED to the flashlight body will have to be very good. This will end up causing the flashlight body to get very hot unless there's some better way to transfer the heat to the air (or the user's hand -- if you can take the temperature). This means a physically larger flashlight, or one with fins or a fan. Or one you can run for only for a short time before turning it off to cool. Sorry, we're bump up against the laws of physics here, and until more efficient LEDs are developed, more light is going to mean more heat, period.
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