[Joykins]

I calculated a long time ago--before the current firmware release--the battery using about 6-7% of life per reading hour and some much smaller percentage during sleep. I figured you should expect to get about 13 hours of reading before the re-charge prompting if you had NO sleep. I can't remember how sleep ate up (maybe 0.3-0.4% per hour of sleep?). I think that 10-day charge was estimated on the assumption that you read 1/2 hour or less a day, though. I usually charge every 1-3 days depending how much I read. At the time my observations were similar to others', that this is typical battery life.

I should really repeat this experiment with the current firmware.