John,
The only ammeter I have found that is more sensitive than 30-0-30 amperes is
VA-1A-50 made by Electronics International Instruments. It is digital and
indicates current down to 0.1 amperes. It also indicates voltage, and has a
built-in discharge warning circuit. Aircraft Spruce has the unit with an
internal shunt listed for US$223. The unit with an external shunt (so you
don't have to run all of your alternator current through the instrument panel)
is US$268. The units are FAA/PMA approved.
Jim Vance
[email protected]
