[TR] TR6: ammeter

[Randall]

> have a volt meter?
> If it does, it would indicate the state of the battery as it is affected
> by
> load and general state of charge...

It doesn't really indicate battery state all that well.  For example, 13.0
volts might indicate the battery is heavily discharged and being charged, or
it is fully charged and the alternator is just barely keeping up with the
other loads.

The Triumph voltmeters were also rather inaccurate from the factory, plus
they are wired in a long way from the battery.  So they aren't even very
good at indicating true battery voltage.  On my Stag, with the battery at 14
volts, the voltmeter reads about 12.5.  Or maybe it's 12.8, really hard to
tell.  12.8 could be fully charged, 12.5 is definitely only partial charge.

The main advantages of the voltmeter IMO are lower cost, less unfused wire,
and not revealing as quickly when the alternator output drops below the
load.  People get excited when the ammeter reads -15 amps at a stop light
with the headlights on; but not so much when the voltmeter drops to 12.5.
Even though they likely indicate the same thing.

The ammeter tells you what is happening right now; at best the voltmeter
tells you what happened in the past.  A quick glance at the ammeter will
also tell you things that a voltmeter never will, like you didn't get the
tail lights turned off.  Well, until you come back to find a dead battery,
that is.

Randall