Hi there,
the problem with the inaccurate battery charge level display is due to the battery voltage NOT representing the state of charge of the typical NiMH cell, in contrast to LiIon, LiPoly, lead acid or alkaline. You don't believe me?
Look here:
http://data.energizer.com/PDFs/nh15-2300.pdfCheck the "Discharge Characteristics" diagram: at the beginning of the discharge cycle, there is a rapid voltage drop, then the voltage remains essentially constant for a long time before the voltage drops again. This is accurately displayed not only by the M10, but also by my Zoom H2 and other NiMH battery powered devices I own. NiMhs also tend to regain some voltage after discharge when not in use.
Compare this to an alkaline:
http://data.energizer.com/PDFs/E91.pdfCheck the "Constant Current Performance" diagram on page 2. Compare.
As a design engineer, I know that the only accurate way to measure the remaining capacity of a Ni-based cell is to add up charge and discharge currents in a so-called "coulomb counter". And this circuit is so expensive, that it was only used in the more expensive laptops. So either we are willing to pay more for an accurate state-of-charge indicator or we accept the simple voltage meter (remember the "battery check" scale on the VU meter of the Sony TCD-5M or Marantz CP230/430?).
I would rather pay for more internal flash memory than for a precise state-of-charge indicator...
On the other hand, the PCM-M10 has such a low power consumption that I never had the problem of running low on battery power while on recording tour. A few months ago, I went to record steam trains on the famous "Schiefe Ebene" grade in Bavaria. Due to the 175th railway anniversary, we had steam trains all day, with a rather flexible timetable. My PCM-M10 was in record standby most of the time, but the battery drain was so low that I didn't need to charge batteries during those three days (yes, I had a pair of fully charged Enerloops in reserve). On the second day, I did not even bother to switch off the M10, but let it go into standby when not in use. Even after that, there was still enough power left to check the recordings and transfer them to the PC.
So stop worrying about the inaccurate display of the M10, In fact, its rather accurate, and the low battery warning still allows you to record for hours. Better yet: leave for your recording session with fully charged batteries, preferably Enerloops or comparable batteries with low self-discharge, then you will more probably run out of memory rather than power.
Greetings,
Rainer