— 10 —
To power off your NMEA 2000 network without breaking the Device’s connection to the battery, you may
need a dedicated hardware solution, for instance, a Garmin NMEA 2000 Power Isolator (part number
010-11580-00). With such a device, you can place the Battery Monitor and other NMEA 2000 devices
in different network segments, each of which can be powered off separately.
The Device is intended to measure battery voltage and current, continuously monitor battery charging and
discharge, and calculate battery status data. An ideal battery always gives and takes 100% of its energy
without any loss. In real-world conditions, the amount of energy available from a battery heavily depends
on the discharge rate and, to a lesser extent, on the battery’s temperature. The charging process, as well,
is not 100% efficient.
Figure 1. Typical capacity vs. temperature graph.
The Device accounts for charge efficiency and battery temperature (if working with an external temperature
sensor), and the discharge rate (via the so-called Peukert’s exponent, see Section IX). Consumed
ampere-hours is compensated for charge efficiency only, and state of charge (SoC) is compensated
for charge efficiency, temperature and Peukert efficiency.
40
60
80
100
120
-40
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-20
-10
0
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Cap
ac
ity
, %
Temperature, °
С
Example of capacity vs temperature
Summary of Contents for NMEA 2000 YDBM-01
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