BlueBM employs BTLE (Bluetooth 4), which was introduced with Android 4.3. BlueBM v9 supports Android 4.3 upwards, but BlueBM v12 and higher only supports Android 6 upwards. If you have an Android version between 4.3 and 6, contact the developer for assistance.

This app connects exclusively with the BM1 lead-acid battery monitoring system manufactured by Nasa Marine Ltd of Stevenage, UK, and is obtainable free from the Google Play Store. It is not compatible with Lithium-ion service batteries.

Privacy Statement - please see.

Known Issues - please see.

SYSTEM OVERVIEW DESCRIPTION.  The Nasa Marine BM1 Battery Monitor device, when properly installed  and connected, continuously monitors the state of a boat's service battery, and one other battery, typically the starter battery for the engine. Calculations are performed by the BM1 on the battery measurements to obtain the charge to full and discharge to empty periods, assuming the current flow remains steady. To perform these calculations, the BM1 needs the battery capacity and the battery ambient temperature. The BlueBM app provides the User Interface to the BM1.

BM1 INITIAL INPUT FROM USER:  Customised "boat name" to identify the BM1 device.  Battery capacity. Battery temperature.

BM1 CONTINUOUS OUTPUT TO USER:  Service battery voltage, Charge/discharge rate in amps, time to full charge/discharge, percentage battery charge. Starter battery voltage.


1.  Before starting, check that your android device supports BTLE (Bluetooth 4), and that bluetooth is switched on.  You will also need location active, not because the app uses it, because it doesn't, but BTLE will not scan without it. Download the BlueBM app from the Google Play store, and allow all permissions requested. DO NOT ATTEMPT TO PAIR WITH THE BLUETOOTH BM1 DEVICE USING THE ANDROID SYSTEM. This is unnecessary and may cause problems.

2.  With the BM1 hardware fully installed and powered, open the app. The first time you use it, you may be asked to confirm installation of the Nasa Marine BM1 battery monitor system. No other hardware is compatible.

3.   Tap the SCAN option from the menu bar. A list of bluetooth devices in range will be displayed.  Select the BM1device from the list, it ships with a default name. The green LED on the BM1 will light.

4.   Once connected, the app will start to display service battery data from the BM1, refreshed every few seconds. Tapping "other battery" from the menu will display the starter battery voltage.

5.   Once connection has been established you need to set the battery parameters and customise the BM1 with your boat name (or whatever).  With the device connected, tap "settings" to bring up the settings screen. Enter the capacity of your battery, and overwrite the default boat name with yours. 8 characters are permitted, anything printable including spaces, upper or lower case. Select the battery temperature.

6.   Submit the new parameters. The red LED on the BM1 will flash quickly, and you need to follow the instructions on the screen popup. This involves pressing the reset button on the BM1 with a pointed object (such as a ball pen) before the timeout expires. The popup may change to "command accepted", and sometimes you will need to shut down the app and power the BM1 down/up to get the settings to register. Once the boat name has been customised, the app will automatically select your own BM1 wnen you scan.



1.     Always close the app when you have finished. This closes the connection and alleviates any problems that might be caused by walking out of range, or whatever. It also updates the history file.

2   To cancel the automatic selection of your customised BM1, select "AUTO" in the menu, and follow the instructions.

3.    The app will build up a history file of the state of the service battery for the last 10 uses of the app.



1.    Open the app.

2.    View the history if required. The previous 10 uses of the app are recorded.

3.    Select SCAN. The app will scan for its own custom-named device and connect to it, assuming it is available, ie in-range and powered up.

4.    View the battery status readings.

5.    Close the app. This disconnects from the BM1.  ALWAYS CLOSE WHEN YOU HAVE FINISHED!!