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 Balthazar Cooper

This is a fantastic little time saver, you can read straight from your mobile phone what your battery voltage is when you have a problem he'll tell you right away he's getting under the hood and taking care of it, it's very easy to hook up, a four year old can do that and stuff. It connected directly to one of my phones but not the other, I don't know why it happened but I think it's likely my phone was just temperamental but it worked straight away with my other phone, I gave it 4 stars instead of 5 stars because the signal only travels about 40 feet and won't go around corners if you step a foot too far out of its range ending in a little red chain icon in the top left corner what pretty cool is, if you go back a few feet, the chain turns green and reconnects. I think someone has doubted its accuracy and I believe it is accurate. I think what happens when something turns on and off, the battery voltage rises and falls a little, and I believe that's called padding or floating voltage? Maybe someone who knows more about this can jump in and comment more, but it looks pretty damn close to measuring the tension. I may update this later when I play with it more, but for now it's pretty good and pretty much worth the money, at least it's better than breaking out a voltmeter and going on to the hood and trying to check your voltage understand, what is up. great that you figured it out right on your smartphone and with your fingertips, I plan to buy a few more for some other cars