Review on 🔋 Innova 3721 Battery and Charging System Monitoring Device by Jarrod Zuvers

Good: Meter accuracy: Reading within 0.01-0.05V of a Fluke 117 meter in the 12-13V range. Problematic: Three auxiliary indicators to help you convert numeric voltage to battery status: battery icon at top, bar graph at right, and colored LEDs at bottom. Everyone says the same thing, they just say it differently. The table on the back of the package indicates the voltage range that each of the stripes/colours represents. That's the problem. Calculating the battery voltage is not that simple. To activate the cigarette lighter, the ignition must be switched on in most vehicles (Euro, Japan). This means the air conditioning, daytime running lights, courtesy lights and radio are all on too, resulting in a reading about half a volt below what you'd get straight from the battery if everything were off. So if this unit reads 11.9 volts with the ignition half-cocked, you're looking at a true battery voltage of about 12.4, which is only 0.1-0.2 volts less than perfectly healthy. But this device sees 11.9 and the red led and icon are on. Yellow would make more sense. In short, the numbers are trustworthy, the indicators are not, interpret them with caution. an educational service for all of us, more than a simple voltmeter with a lighter. With a good battery and alternator, the voltage should go from about 12.6 to 14.6 with the engine running. 15V and more signals a problem, in this case the LED turns on the yellow/red LED accordingly. Fits snugly in the cigarette lighter socket, the hinge is smooth, the display is easy to read. Made in China. highlighted.