Review on ⚡ Waterproof Battery Monitor DC 4.5-150V Voltmeter Tester for Automative Electric Cars, Golf Cart, E-Bike, Bicycle & Motorcycle - Small Digital Gauge with 0.56'' LED (Blue) by Shane Yay

I'm giving this item one star for now but we'll see if the seller does the right thing. First I installed it on my 48v golf cart and it ran the full 3 hours. In terms of installation it should be fairly easy if you can make your own template and know how to use a dremel. Wiring couldn't be simpler as one wire goes to the positive terminal of your battery and the other to the negative terminal. This is the only reason for the 1 star rating. If they can send me a device that lasts more than 3 hours I will come back and re-evaluate. Edit: I contacted the seller about my above issue and they responded quickly and shipped me a new unit. I installed a new device and it's been a week now and it's still working as it should. So I'm giving it 4 stars for now.