Nasa'a BM-1 is designed to monitor the performance of 12V lead acid battery systems, including AGM and Gel types with capacities of up to 600A amp hours. The battery monitor continuously monitors voltage, current (charge or discharge), number of amp/hours (charge or discharge), the batteries state of charge and the time to charge or discharge. BM-1 also monitors the voltage of the engine start battery. This information results in a more efficient use of the battery, which can enhance battery life and reduce the risk of failure. Supplied with a precision 100 amp shunt and a prefabricated cable assembly to ensure simple DIY installation.

So how does it work?
BM-1 has a simple, intuitive display that shows the service battery voltage, charge/discharge current. state of charge and time to charge/discharge. The battery monitor also warns you 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 track of power consumption, with a second input on hand to let you monitor the voltage of the starter battery. The internal software incorporates two algorithms. One based on integrating amp hours over the charge and discharge cycle, the other based on an adaptive mathematical battery model.

A unique feature of the battery monitor is its ability to use information from both algorithms during the charge/discharge cycles to continually update its performance. As a result, BM1 never needs to be re-sychnronised with the battery, unlike many other systems that rely solely on amp hour integration. The algorithm includes Peukert's equation to ensure accuracy over a wide range of load currents. BM1 does all of this whilst consuming a meagre one and a half milliamps.

Specifications:

Supply Voltage: 8-16 V DC.
Supply Current 1.5 milliamps.
Battery Capacities: 5 -600 amp per hour.
Maximum Load Current: 100A.
Maximum Charge Current: 100A.
Shunt Standard: 50 millivolt @ 100A.

Cables Supplied:
100A shunt link to M8 Ring terminal.
5 Metre from display unit to battery - fused and fitted with ring terminals for shunt, fuse holder and M8 ring terminal to battery.