It is, but for the purposes of learning to use a voltmeter, simply checking from a known ground to a potential source of voltage is a good start. As long as a primary, non-computerized circuit ...

A voltmeter isn’t the best gauge of your boat battery’s condition. (Pun intended.) But a voltmeter can provide information useful to savvy boaters. Here’s how to use yours.

The circuit in Figure 1 is an easy approach to testing batteries without exiting the voltmeter. The battery holders in sizes AAA, AA, C, and D make this tester so much faster than a voltmeter. You ...