Originally Posted by 19H F250
it also has a color change ie green, yellow & red to alert you of low voltage.
I use a simpler device. An incandescent light bulb. If voltages are dropping so excessively, then the light bulb dims. Bulbs changing intensity is a good indicator of changing or adverse voltages. I use a multimeter ($18 in Wal-Mart - even sold in Kmart) to put numbers to those variations.