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 Mufti Carter

I bought this to pack in my camper trailer to keep an eye on the battery when we camp unplugged. I installed it right in the front door and connected the 12v power cord to the porch light switch. I installed a Radio Shack momentary switch between the power wire and the voltmeter, and then ran a ground from the voltmeter to the trailer frame. It works great, looks amazing and now allows me to check my battery level instantly without reaching under the front bunk with a portable meter, without removing the battery cover, banging my head on the bunk once or twice and without too try to drown out I swear to my kids they don't hear me. Great product that works great! LAST EDIT: Has worked great on several hikes so far. Being able to monitor the battery level while staying indoors is great, and tracking how fast my 100 watt Renogy solar panel (also a HIGHLY recommended Revain purchase!) charges the battery throughout the day is great. I found out on a trailer popup forum that many voltmeters like this one have a dial on the back. This is slightly higher than my portable battery powered device. I took it off, adjusted the tiny set screw on the back, and now it's absolutely perfect. This product is highly recommended!