Review on 12V Car Digital Voltmeter Gauge by John Chembola

I bought four of these to use with large separate wet cell batteries wired in series to give 48 volts DC. This battery will also charge from a 48V charger. Before installing, I tested each voltmeter on a bank regulated DC power supply. Three devices show the same voltage, one shows 0.1 V less (example: 12.8, 12.8, 12.8, 12.7). If the voltage drops too far, they go out. For my purposes that accuracy and low voltage drop doesn't matter much as it was an economical way to see each battery individually and I can tell if it's being incorrectly charged. If you see a battery drop below 12.0V, you should know that the specific battery needs to be tested to determine the cause.