Battery Monitor BM2 4+

I am using this app to monitor an AGM house battery and it does the job nicely. Historical graphs are great for monitoring.

There is room for improvement though:
Sometimes the app fails to connect to the monitor requiring a force-quit and restart.

It is difficult to tell when the data is out of date (when disconnected) - changing the colour from blue/red to grey would be useful.

An iOS14 Widget would be great

Requesting Location access seems suspicious. I don’t know why this would be linked to alerts.

Asking for the battery type would allow you to hide some of the tests - a Cranking Test doesn’t make sense for an AGM battery.

The graph screen does not update automatically. You have to return to the main screen and reopen it to refresh. The graph screen is horizontal (which is fine) but only supports the phone rotated -90° - at +90° the graph is upside down

The main screen shows a small graph with a lot of empty space underneath (on my iPhone 12). The graph should be taller.

Overall I’m really happy with this app. A feature I would love to see is a temperature reading and graph, similar to what a another brand currently has. That obviously depends on whether the meter has a thermometer built in which I highly doubt, but if they do consider it in their next model I would get another one straight away. Also, it would be a good feature if we were able to have a calibrate function in the settings in order to manually adjust the voltage reading because the last digit of the of the meter isn’t the same compared to my multimeter. Also having that option would be great because as time goes by the accuracy may drift due to aging of the meter.
Apart from those things I very happy with the app. Well done

It’s a great app if you only monitor one battery. When you monitor more batteries, it’s awkward to switch the display between the batteries - you have to go into the settings rather than switching in the display. Also, when you get notifications, you can’t determine which battery generated the notification. If those improvements were made, I’s give it 5 stars.