I have two Cygolite Ranger 1400 headlights. Each has been sent back to the mothership for repairs - both plugs for the mini-USB came loose. But now the issue is batteries. For a while, they both worked great. Then one would just die in under 15 min. I finally labeled them with a silver Sharpie - #1 and #2 . #1 seemed to be culprit. It is the older of the two, so. But even labeled, I wasn't sure; I kept second guessing my memory, "wait... did #2 die last time?". A proper test was in order.

Yesterday, I fully charged both lights. The green light goes from flashing to steady green when it's charged. I set the stopwatch and turned them both on High.
- #1 died in 4 minutes and 20 seconds
- #2 died in 2 hours (yes, hours) and 30 seconds

I thought "Okay, good. I have one dead light and one good light." I tossed #1 in the bin and charged up #2 for this morning's ride.

This morning (at 5:45am), after charging #2 all night, it died in 9 min... just long enough for me to get to the darkest stretch of road. Of course.

So. What have I learned? Nothing. Well, I did learn that I can't trust either light and already ordered a new light. But, what can I learn here? Did running #2 all the way down ruin the battery? Neither light is new - #2 is just newER than #1.

Side note, but a big one: I was VERY careful to keep track of which light died when, etc. #1 died in the "test." #2 made it 2 hours in the test... and died in 9 min. this morning.