Test Equipment

DC Amp meter (inline or clamp-on)

Volt meter

I actually use an inexpensive digital multimeter. Don't even think about using one of the old analog ones. You need decimal place accuracy for voltaqe to monitory batttery health and performance. Even the cheapest digital meter will do this for you.

BTW - you may be tempted by those cool blue LCD volt and amp meters on eBay (I was) - don't do it - they require seperate 12v feed.

Load tester

OK, well this is an analog voltmeter, but paired with a high-resistance load (heating coil). Sears has one that's fairly high amp. I guess the professionals use one incorporating a carbon pile for the resistance load which can go to several hundred amps. This will help you measure the "sag" or voltage drop of the battery under load.

Continuity tester

A/C outlet tester