Review on Battery Monitor ANCEL BM300 - Bluetooth Voltmeter for 12V Solar Power Systems/RVs/Motorcycles/Boats/Cars/Trucks - Voltage Charging Cranking System Test with Alarm by Daniel Steele

The hardware of the device is very good, accurate, easy to install and small, so it can be hidden. The only negative is that the instructions say to stick it to something with velcro that comes with the kit, but there is no velcro in the box. Bluetooth range is pretty good even with it installed under the metal hood of my car. Installation instructions were clear, although clearly not written by a fluent English speaker. The app is actually pretty good (apart from the bad English help text) with one big problem: it's calibrated for every standard chemistry I know of. Begins to complain about low charge at too high voltage; and gives 'Low Power' notifications every time I approach the machine, which is very annoying. The rest of the app features are good. If the settings for the connected battery could be adjusted I would give it 5 stars.