MICTUNING MIC-DV-077 LED Digital Panel Double Voltmeter, Rocker Switch Style Voltage Monitor Blue for Car Pickup RV Truck Dual Battery Pack

I bought this to run isolated batteries in my car so that I could monitor voltage on both batteries even when they weren't connected. I got it, hooked it up to a DC power supply, and connected the leads. The MAIN voltage shows up fine, but when I connect it to the "AUX" connection point, nothing happens. When I connect the MAIN and AUX connectors, voltage is displayed. To show only one, I shouldn't have to keep both on all the time. What if I installed a momentary switch to prevent it from being "always on," as other reviews suggest? If I only want to check the AUX battery, it will not read voltage. This is a major design flaw that should be fixed so that you can read either one on its own. br>br>When you combine that with the lack of a power switch, you end up with a dead battery over time. I understand LEDs don't draw a lot of power, but I don't want something in my vehicle turned on all the time when I'm not in it.

Alianna Castro

| Jan 04, 2021

This was installed in my motorhome so that I could see the chassis and house battery voltages while driving. This is exactly what I'm looking for. Main was connected to the switched chassis power, and Aux was connected to the house battery. I wanted it to only show up when the ignition is turned on. The primary purpose of this display is to monitor the system that connects the batteries together to charge from the alternator while driving because I frequently run large loads while driving, such as the propane refrigerator, and I normally dry camp, so it's important to ensure house batteries are charging while driving. Others have complained about precision, but mine is accurate to a tenth of a millimeter. 1V, and I have more precise displays, such as amp-meters. For real-time monitoring, hour counters are used. For $14, this is an excellent product. I'd definitely buy it again. I worked as an electrical engineer for many years before retiring.

Dior Riley

| Mar 07, 2021

The first issue is: I connected one battery, shorted the two pins for the two battery inputs, and the two displays read differently by 0. From one to the other, a voltage of one volt is applied. Then I connected a Fluke voltmeter and discovered that one of the voltages was 0. 01 higher than the other. One is too high by a factor of ten, while the other is too low by a factor of ten 07V. I tried a few different batteries and got the same results. A normal battery voltage changes about 1 volt from fully charged to mostly discharged, so I consider this to be a 10% charge level error. br>I purchased this dual battery monitor to check the voltage of two batteries in a starter and "house" battery setup. The batteries can be isolated, ensuring that any accidental overuse will only drain the house battery. Because the isolation is automated and equal voltage means connected, I need to know if they're both charging at the same time. That won't work here; they'll never be on an equal footing. br>br>Problem number two: Any reading requires the presence of the main battery. There is no display if only the Aux battery is present. So if the starter battery dies, I can't check the status of the house battery to see if it can be used to start my truck. To find out, I'll need to get a voltmeter. As a result, it's impossible to call it a dual voltmeter. It's closer to an hour and a half. br>br>By the way, the current draw is around 17mA at the moment. It's not too bad if left on all the time, and since it's connected to the battery, there's no obvious way to turn it off. You can connect the device's ground terminal to the ground with a switch. It's automatic if the switch is a relay, and the relay energizes when the ignition is turned on. br>br>I can't return it because I bought it before I installed it, but I would gladly do so. Not recommended, but I gave it two stars because I could see why someone would be willing to overlook its flaws in exchange for the low price.

Korbyn Hughes

| Jan 05, 2021

It arrived quickly and in good condition. In addition to this, I installed a dual battery system in a UTV. It was simple to make a wiring harness and connect it to the batteries, and it works perfectly. In daylight, it's easy to see each battery's voltage, and it looks good at any time of day. The purchase was a success. edit: br>br>br>br>br>br>br>br>br It's been 10 days since the meter was installed. It consumes power and, if not recharged, will deplete your battery over time. Install an on/off switch to turn off the power to the main lead to solve the problem. If installed in a frequently used vehicle, you may not notice the constant power consumption; however, if installed in a vehicle that sits for extended periods of time, this item will completely drain your battery at current measured consumption rates after 10 days of use. When I realized it didn't have a built-in off switch, I was concerned about measuring actual power consumption. This item would be a more complete kit if it came with parts to make a wiring harness and if the meter had a real rocker switch to turn it off. I still give it 5 stars because if you're into something like this, you're probably already familiar with how to make a wiring harness, and you're probably already aware that connecting a constant draw to a battery will result in a dead battery over time. the meter itself works very well.

Zoya Morris

| Nov 30, 2021