On Fri, 18 Jun 2010 14:32:52 +0100, Bodincus
wrote:

(18/06/10 13:58), Chris Blunt:
On Fri, 18 Jun 2010 13:31:24 +0100,
wrote:

B) However, that proves my point. The relationship between voltage and
residual power is non-linear, and the residual power inside the battery
- whatever type it is - is not related to the voltage between the dipoles.

So WHY the devices are still using voltage as a value to measure if a
battery is still delivering the needed power?

What else could they measure?
During idle time, small bursts through a fixed resistance circuit to
measure both voltage (and its drop under load), and current.
A bit of computation and you can measure how much oomphf the cell has left.

The additional components required to do that will all add additional
cost and weight to the device, as well as further draining the
battery. It doesn't make much sense to unnecessarily put extra load on
a battery when what you are trying to achieve is to squeeze as much
life out of it as possible.