Review on 🔋 12V Digital Voltmeter: DROK 0.56" DC 3-30V Voltage Tester with Bright Green LED Display, 2-Wire Volt Meter Detector for Solar Battery Monitor, Car Motor Panel Mount - Ideal for SEO by Aaron Bannister

It works by providing a relatively accurate visual indication of the health of your battery system. I used it as my main solar panel monitor for 2 years. I note that this system was in very difficult conditions: on the tops of mountains, during dust storms and during monsoon rains. I pumped the boosters in and out of the batteries with great care. With all this handling, I was sure that this little voltmeter would burn out in a month. But it just keeps ticking. In fact, I've come to the conclusion that the faint green glow calms the night light. It draws so few amps that I'm not worried about it staying on. I am giving one star because the plastic is not of the highest quality. But the proof is in the pudding. This little man has a firmness. Costs money!