LEDAdd1ct
Flashlight Enthusiast
Technology has come a long way and we now have many choices.
I am always fascinated by blackout lights, flashlights/lanterns with crazy long runtimes.
Below is a chart comparing two LEDs at 150mA drive current:
The LED on the left will produce approximately 54 lumens at 95 CRI 7A2 tint while consuming 0.421 watts at about 3200K.
The LED on the right will produce approximately 87 lumens at an unspecified CRI 5C1 tint while consuming 0.411 watts at about 4000K.
Using four 3.2v LiFePO4 32650 cells at 5000mAh capacity (which are sitting on the table in front of me) wired in 2S2P for 6.4V output, we get:
6.4V * 10mAh = 64 watt hours
64 watt hours / 0.421 watts = 152 hours runtime
Either of these two LEDs will allow for a very long runtime at 150mA drive current.
I already own the host and the batteries; the LED and driver are easy enough to acquire.
My questions:
1) For an emergency long runtime light/lantern, which one would you go with?
a) 54 lumens at 95 CRI and 3200K CCT at 7A2 tint
b) 87 lumens at (?) CRI and 4000K CCT at 5C1 tint
2) Would one would you choose?
a) Diffuser (i.e., a lantern)
b) Ceiling bounce
3) Do you think 54 high CRI or 87 unknown CRI lumens are enough for a long runtime light in a blackout?
a) Yes
b) No
4) Any other thoughts?
* * *
This lantern will happen. I just cannot decide between the two LEDs.
Part of me thinks a warm white/relaxing/high-CRI light is the way to go.
However, the other part of me thinks that at the end of the day, being able to see is the most important objective,
and 87 lumens will do a better job of doing that than 54 lumens.
Thank you!
I am always fascinated by blackout lights, flashlights/lanterns with crazy long runtimes.
Below is a chart comparing two LEDs at 150mA drive current:
The LED on the left will produce approximately 54 lumens at 95 CRI 7A2 tint while consuming 0.421 watts at about 3200K.
The LED on the right will produce approximately 87 lumens at an unspecified CRI 5C1 tint while consuming 0.411 watts at about 4000K.
Using four 3.2v LiFePO4 32650 cells at 5000mAh capacity (which are sitting on the table in front of me) wired in 2S2P for 6.4V output, we get:
6.4V * 10mAh = 64 watt hours
64 watt hours / 0.421 watts = 152 hours runtime
Either of these two LEDs will allow for a very long runtime at 150mA drive current.
I already own the host and the batteries; the LED and driver are easy enough to acquire.
My questions:
1) For an emergency long runtime light/lantern, which one would you go with?
a) 54 lumens at 95 CRI and 3200K CCT at 7A2 tint
b) 87 lumens at (?) CRI and 4000K CCT at 5C1 tint
2) Would one would you choose?
a) Diffuser (i.e., a lantern)
b) Ceiling bounce
3) Do you think 54 high CRI or 87 unknown CRI lumens are enough for a long runtime light in a blackout?
a) Yes
b) No
4) Any other thoughts?
* * *
This lantern will happen. I just cannot decide between the two LEDs.
Part of me thinks a warm white/relaxing/high-CRI light is the way to go.
However, the other part of me thinks that at the end of the day, being able to see is the most important objective,
and 87 lumens will do a better job of doing that than 54 lumens.
Thank you!