Bit of an odd one.
I decided to use my back-up Edirol R09 last night to tape a show. It had a pair of fully charged 2700mAh batteries that were charged last Thursday night and placed into the recorder on Friday pm. I didn't need to use the recorder and it remained in my gear bag until last night, when I took it to a gig. On departing the venue, I went to switch off the recorder, only to find it already off. Switching it on gave me the low battery power warning.
When I got home, I found that it had only recorded for an hour and that I had to open the file in CDWave because of the file header issue. I would not have expected these batteries to have drained their power sitting unused in the recorder for less than five days. Normally I charge the batteries and only put them in the recorder before I head out, so perhaps a lesson learned there.
Question is, why would the batteries have drained after sitting in an unused recorder for five days?