> It sounds like the main benefit of this tool is
> to tell you RIGHT NOW if a battery is
> bad or not, whether or not it is fully charged,
> and whether or not it is installed.
> If you have a bit more time on your hands than
> a typical repair person (for whom time = $$$)
> and you have vehicle to install the battery in,
> you should be able to diagnose batteries, charging,
> and starting sytems with just a voltmeter and a
Hydrometers are fairly useless with most modern 'sealed' batteries.
And an inexpensive load tester plus a charger (and time to charge the battery)
will do fine for testing without a vehicle.