Description
- Supply voltage:BM-1 12V8 – 16 Volts DC
- Supply current1.5 milliamps
- Battery capacities5 – 600 AMP Hour
- Load current100 AMPS Maximum
- Charge current100 AMPS Maximum
- Shunt Standard50 millivolt @ 100 AMP
How does it work? The minimum information required to monitor the state of charge of a battery is the terminal voltage and the charge/discharge current **. The BM1+ measures both these parameters and computes the state of charge using a complex well proven algorithm. A simple and intuitive display shows the service battery voltage charge/discharge current state of charge and time to charge/discharge. The instrument also warns the user when the charge level is too low so that load can be shed or charging commenced to protect the battery. A resettable Amp Hour counter is provided for checking the efficiency of the charging system or keeping a track of power consumption and a second input lets the user monitor the voltage of the starter batter.
The simple display format does not mean the internal software is unsophisticated. In fact two separate algorithms are used. One based on integrating amp hours over the charge and discharge cycle the second based on an adaptive internal mathematical battery model.
A unique feature of the BM1+ is its ability to use information from both algorithms during the charge/discharge cycles to continually update its performance. This means that unlike many other systems that rely solely on amp hour integration the NASA BM1+ never needs to be re-synchronised with the battery. The algorithm includes Peukert’s equation to ensure accuracy over a wide range of load currents.
The BM1+ does all this whist consuming a meagre one and a half milliamps. It is a true battery monitor easy to install and excellent value for money.
** Some say that they can calculate the state of charge from the terminal voltage only but as we all know the terminal voltage falls when the battery is under load and rises when under charge. This fall and rise can be quite substantial especially when a heavy current is flowing so how can the terminal voltage be used to calculate anything without knowledge of the magnitude of the current involved?.
In The Box
Display; 100 AMP shunt link to M8 Ring terminal; 5 m cable.
Upgrade Options
Alternative or higher-specification products you may also wish to consider.
NASA
NASA Clipper Wireless Wind with MHU and Data Box
The Clipper wireless wind is supplied with a wireless masthead transmitter, a base unit and a Clipper Wind display unit. The wireless masthead transmitter is powered by an internal battery which is charged from ambient light using a small solar panel. A few dull days will not affect performance. When fully charged, it is capable of two thousand hours of full operation in total darkness. The masthead transmitter sends data wirelessly to the base unit, which is powered by the vessel's 12 Volt supply, the base unit receives wind speed and direction data from the masthead transmitter and sends it to the Clipper Wind display or any other compatible NMEA display unit. The Clipper Wind display is in the industry standard 110mm square case. Exceptionally large and clear display with 60 segments for full 360 degree direction indication.
NASA
NASA Cruiser Wireless Wind System
Cruiser Wind. Large High resolution 360 degree display of apparent Wind direction. User selectable pointer style. User selectable Windspeed in knots, M.P.H or K/M/H. Low current consumption – 35mA @ 12V + 20mA for backlight. Dimensions – 132mm x 98mm x 29mm. Supply voltage Nominal 12v DC. Supply current 17mA. Wind speed and direction NMEA data sentence MWV to any compatible NMEA device. Supply voltage 9.0 to 15.0 volts – supplied with in line fused power cable (1 Amp).
NASA
NASA
NASA Target Wireless Wind System
Full 360 degree display of apparent wind. No dead quadrant. Digital wind speed in knots. keypad adjustment of mast-head alignment. Supply voltage nominal 12v DC. Compact cockpit display unit 132 x 98 x 30mm. Sleep time > 15,000 Hours. Operating time > 2,000 Hours. Charging time < 150 Hours of bright daylight. Fully charged with no further daylight.
