User manual

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Rolls Flooded models with Advanced NAM may have a slightly higher End Amps/
Return Amps/Tail Current set point as the cells are less resistant to charge and
current output will remain slightly higher at 100% SOC. (2% recommended, 2-5%
range) An adjustment to this set point may be required when these models replace
other Flooded batteries. Test specific gravity at Float Charge to confirm 100% SOC.
WARNING: The End Amps/Return Amps/Tail Current setting, combined with sulfated
batter(ies), may confuse the charger as added resistance will reduce the flow of
current. This may falsely trigger the charge to end the Absorption charge prior to
reaching 100% SOC. Test specific gravity regularly to confirm the battery bank has
reached 100% SOC and adjust this set point and/or Absorption time as necessary.
LOW VOLTAGE DISCONNECT (LVD OR LVCO)
Many charging systems offer the ability to program a Low Voltage Disconnect (LVD)
or Cut Off (LVCO) which triggers an alternate power source (often a generator) to turn
on and begin charging the battery bank. When the programmed low voltage setting
is reached, the system initiates the charge source which then safeguards from over-
discharge. By default, this may be set by the charger manufacturer at 1.75 volts per
cell (VPC). Always verify the default settings and adjust as required.
LVD/LVCO setting is often a personal preference. Deep cycle batteries are intended
to be discharged no more than 50%. Allowing the battery bank to discharge to a lower
voltage will reduce over all cycle life. Alternatively, a higher set point may result in more
frequent use of the alternate charging source (ex: generator) when discharge reaches the
low voltage cut-off. To maintain cycle life and prevent heavy-discharge, Rolls recommends
setting LVD/LVCO between 1.90-1.95 volts per cell (VPC). This may be adjusted up or
down, depending how often you wish to run the alternate charging source (generator or
alternative power) when the voltage of the battery bank reaches the programmed set point.
WARNING: LVD/LVCO only cuts off the draw from the inverter/ charger. It does not
disconnect all loads from the battery bank. A prolonged draw will eventually lead
to over-discharge and possible battery failure or damage.
OTHER CHARGER MODES
Inverter and charge controller manufacturers may include additional settings. Rolls
recommends contacting the manufacturer for guidance and to better understand how
these settings function. Default settings are typically not in line with the required
charge voltages and time. Charge & Float voltages and Absorption time calculations
are provided by the battery manufacturer and are specific to the make & model.
See Table 2 (a & 2 (b Flooded Charging Parameters.
FLOODED LEAD-ACID BATTERY - CHARGE EFFICIENCY / CHARGE FACTOR
Charge efficiency is a measure of the energy you may take out of a charged battery
divided by the energy required to charge it. Charge efficiency will depend on a number
of factors including the rate of charging or discharging. Charge efficiency for Flooded
deep cycle models is typically 80%. This should be reduced 1% per year after the third
(3) year of operation.