Log-Log Plot for Comparing Lumens - Run Time - Models?

Hi: I've been trying to figure out which single AA flashlights are the most energy efficient. I started with a scatter plot of 70 some odd lights that used AA cells but it's not fair to compare lights with different battery capacity. Also needed to use LOG(Lumens) & LOG(Minutes) to get some separation between lights. So made a plot of only single AA lights and then of only lights that seemed better in terms of Lumens & Time. A table of all the lights is at: https://prc68.com/I/FlashlightPat.shtml#BL-Table

The below plot is based manufacturer's data. Is this a valid way to compare efficiency?
This plot is also at: https://prc68.com/I/FlashlightPat.shtml#BL-Plot

I'm not clear on this, does minutes indicate the advertised runtime at that mode, or is this a log-log of an actual runtime test? If it's the former, step downs make this chart fairly meaningless for any non-constant mode.

Brooke said:

Hi: I've been trying to figure out which single AA flashlights are the most energy efficient....

The below plot is based manufacturer's data. Is this a valid way to compare efficiency? ....

Click to expand...

No, for a few different reasons.

There is a CPF member @reppans who has done some detailed testing, so searches for his postings may provide more info and insight.

Just another note, lines between the points really don't add much to this plot - I'd suggest removing them.

Even if you stipulate that advertised output and runtime info is "accurate" the shape of the curve (regulation) is highly relevant.

The ANSI-FL1 standard is determined by continuous runtime until the light output drops to 10% of the initial value, as measured 30 seconds after turning the light on.

You can easily imagine two very different curves with the same start- and end-points (same "output" and "runtime" then) ... but very different total "lumen-hours" and thus markedly different efficiency.

You need to compare runtime graphs - the one with the biggest area under the curve is your winner. Of course the AA cells used need to be the same for all graphs.