A few days ago I wrote about my AA-powered DiNotte light, saying how much I liked it but expressing some doubts about its runtime. So I did the geeky thing: I actually tested it. Simple protocol, really: Fully charged batteries, the same ones that were supplied with it. The light was turned on high, installed as it would be on my bike, with a fan blowing on the light because the housing is a heat exchange device and gets very hot. And then I had a Timex Ironman watch with a continuing alarm going off every five minutes so I could check on the light’s status.
Results? The light lasted longer than I did. Between 115 and 120 minutes, the light went from high to energy-saving low mode, and then kept cranking until 255 minutes, at which point it was time for bed and I ended the experiment.
I assume that a fresh set of lithium disposable batteries would last at least as long as the rechargeables (though I have no evidence either way on that). But if nearly two hours on high and four hours 15 minutes of total life without changing isn’t quite enough for you, you can try tinkering (see here and here). I’ve laid in nearly all of the supplies necessary and plan to make it a winter project.