Review on CTEK (40-149) CTX Battery Sense - Smart Battery Monitoring via Mobile Phone by Keith Wolff

The device itself is quite easy to use. Normally connected to the car battery. Bluetooth connects to my Samsung S7 with no problems. However, the included phone app is very poor. Connectivity is often difficult. He often falls. It has screens that sometimes don't update. Chart readings are sometimes questionable and confusing. The graph shows the scale up to 100% (not the actual voltage reading) and is often off the graph so you cannot see the measurements. After fully charging the battery (or turning off the device), it seems confused, and it takes about 24 hours to figure out what the readings really are. During this time I see a sharp drop until the voltage reading stabilizes. After that it looks right. It is read every 5 minutes and the ups and downs are correlated with the vehicle's travel time. We believe we have parasitic consumption on our minivan and according to the chart the voltage drops about 0.1V every night between 2:00am and 7:00am. . The battery died after a few weeks (which led us to buy this monitor). This matches my handheld multimeter measurements. It works pretty well if you give it a day or two to get used to your battery. I wish the app was better and you could see and export actual voltage measurements.