Installation and Operation
16
900-00264-01-001 Rev A
Not all chargers measure this in amperes. Many chargers hold the absorption for a timed period
(often two hours), assuming that the current will taper down by then. However, if the charge
ends before the current tapers to the desired level, the battery may not reach 100% SoC.
Repeated failure to charge the batteries to 100% will result in decreased battery life. If possible,
use a DC amp meter to observe and time the current as it tapers down. The absorption timer
can then be set accordingly.
Float Stage
The float stage maintains the battery at a full state of charge, counteracting the natural tendency
of a fully-charged battery to slowly discharge when sitting idle. During the float stage, the
battery is supplied with a constant voltage of 13.6 Vdc to keep it "topped off" at 100% SoC.
Equalization
To maintain optimal battery health, an equalization charge should be performed every 12
months. Equalize at 14.4 Vdc for 4 hours
.
Freshening Charge
A maintenance or “freshening” charge should be given to batteries that have been in storage.
The freshening charge must be appropriate to the battery model. All charging should be
temperature-compensated (see page 17). With a multi-stage charger, the voltages for each
stage are set as noted on page 15.
Notes on NorthStar NSB BLUE+
®
Charging
The current requirements for the absorption stage are usually minimal; however, this will vary
with conditions, with battery age, and with battery bank size. (Larger banks tend to have higher
exit current values for the absorption stage, but they also have higher float current.) Any loads
operated by the battery while charging will also impact the requirements for the charger, as the
charger must sustain everything.
If using a battery monitor device such as an OutBack FLEXnet DC, program the charge
efficiency to 97%; return amps to 1% of capacity; and charge voltage to 0.4 Vdc below
absorption. It is highly recommended to use the NSB BLUE+
®
batteries in conjunction with a
battery monitor such as the FLEXnet DC and OPTICS RE for proper monitoring and data
recording. The programming may be used with the following settings:
Amp-Hours
: Based on the 20-hour capacity
Charge Time
: 1 minute
Charge efficiency
: 97%
Return Amps
: 1% Adc
Charge voltage
: 13.7 Vdc