Review on Battery Monitor BM2 BM3 Bluetooth 4.0 Wireless Battery Tester for 12V Automotive Battery Load Testing, 🔋 Monitoring Automotive Charging Systems, and Cranking Analysis. A Digital Battery Analyzer Applicable for Android & IOS Devices by Peter Parks

Can't make it work. I hooked it up to a standard 12+ volt lead-acid car battery that was tested with a multimeter. The polarity is correct. I downloaded the app with no problems. I see the device under Available Bluetooth devices on my smartphone. Samsung Galaxy S9. When trying to pair, you will be asked for a PIN code. I couldn't find the pin in the manual. Found other reviews that say no needle is needed. And it will connect automatically when Bluetooth is on and the device is within range. I have bluetooth and within 3 feet of where the device is located. I open the application but it doesn't connect. I ordered this about 1-2 months ago and only opened and installed it yesterday for the first time. Unfortunately I missed the return deadline.