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 Christopher Gulledge

What a great easy to use product that costs many times less than other monitors. The Bluetooth connection was solid and reliable. I have a monitor hooked up to a battery in my garage and I can get readings from the monitor through my phone from across the house. This monitor has a stronger connection than my $120 Plantronics headset! I've never lost contact at home either - whenever I left the house and then came back, the monitor would automatically connect to my phone. Shouldn't Bluetooth do this, you ask? Yes, on paper. But in reality this does not always happen. This monitor is the first of many Bluetooth devices that I own. The power consumption is negligible. I leave this monitor in the garage on battery and after three weeks of use it still hasn't had a single discharge. What to expect for a Bluetooth low energy device. Why only stars and not five? Simply because I don't have any other equipment to verify the accuracy of the monitor's readings. If I knew the reports he gives are accurate to within 0.1v he would be getting five stars from me in no time. And it may well be true! I just can't know. UPDATE: I bought a DMM and checked the voltage of a battery with this battery monitor and it showed the same voltage as the battery monitor. So I've upgraded my rating to five stars, which confirms the monitor's accuracy.