Dataman S4 - Manual (Page 30)

DATAMAN S4 MANUAL
30 INFO KEY
that the temperature is too high or too low to
be monitored. (below 5°C or above 45°C). The
method used for detecting temperature is to
measure the voltage across a thermistor, which
is in physical contact with the battery, which
does not make an accurate thermometer - but
it is good enough to observe a 5 degree rise.
S4 does not permit fast charging of batteries
which are outside the 5 degree and 45 degree
limits, because battery manufacturers do not
recommend it.
The Fuel Gauge
Across the top of the display is a bar-graph
showing S4's estimation of remaining battery
capacity. This really is an estimation: it is not
possible to measure charge in a Nicad by
looking at its voltage or by any other means.
S4 keeps track of power usage from the last
fully charged state. The FUEL GAUGE
represents S4's guess at how much charge
remains. It isn't perfect - but it's a lot better
than no guess at all. The FUEL GAUGE will be
wrong in the following circumstances:
1. If the battery was changed or removed
2. If S4 has been switched off for a long
time. (that's because S4 cannot
estimate self-discharge).
In either case the FUEL GAUGE will
correct itself when the battery is charged.