Technical Manual

Chapter 3 • Introduction
D C U M a i n t e n a n c e a n d O p e r a t i o n M a n u a l 15
When operating in the low power mode, the DCU 2+ compares the battery
state-of-charge to the seasonal state-of-charge threshold every 60 minutes.
Initial battery protection settings are automated based on GPS-provided latitude
and longitude and will only be recalculated if the GPS coordinates change by more
than 1 degree in magnitude. Battery protection settings can be viewed in the “wall”
or “wp” command based on firmware version can be monitored and written via the
local menu or over-the-air. See Commissioning on page 19 for more information.
N
OTE Changing default parameters may void battery warranties. Contact Aclara if
needed.
DCU 2
The DCU 2 uses a different power management mechanism than the DCU 2+, and
Aclara has recently released Power Board Firmware Version 2.08 for the DCU 2.
This version enhances the DCU 2’s solar charging algorithm to improve DCU
battery life by reducing overcharging through PWM action on charge current
during longer periods of solar charging activity. The benefits of the new charging
may take some time to realize in the field, but customers may see a side-effect
difference in their “Charging Current” data.
The H-board provided the headend with 4 different messages that are seen in the
DCU diagnostics page which are loaded voltage, unloaded voltage, charging
current, and temperature. These values are read and reported at different intervals
throughout the day.? Specific to the current reading, the H-Board takes an internal
fast snapshot reading every 5 minutes for one hour. The max current value read in
the hour is reported to the headend. When charge current was constant, this
produced a reliable reading.
Parameter Description Default
Non-Winter SoC
Threshold
Non-winter season
state-of-charge threshold for
entering low power mode
Initially set automatically based
on GPS location
Winter SoC Threshold
Winter season state-of-charge
threshold for entering low power
mode
Initially set automatically based
on GPS location
Winter Start Day
First day when winter-type
weather occurs
Initially set automatically based
on GPS location
Winter End Day
Last day when winter-type
weather occurs
Initially set automatically based
on GPS location
Wakeup Period
When system is in low power
mode, this is the maximum time
interval before the DCU is
allowed to run from the battery to
perform full power operations
(daily shift)
4320 (minutes)
Wakeup Local Time
Local time of day when the
system wakes up during low
power mode
1320 (minute of day; this is the
1,320
th
minute of the day, or
10:00 p.m.)