Battery Low Voltage Tolerances
The battery charging period varies depending on the amount of discharge during backup. Figure 13.2 shows the typical
recharge curve for a fully discharged battery.
Initial charging at maximum current (limited by charger). V
minimum voltage at which the UPS will shut down power to the
Charging rate drops as battery voltage increases.
Battery cells are at maximum voltage, UPS continues to provide a
"trickle charge" to keep the batteries a maximum charge capacity.
= 324 V
= 230 V
FIGURE 13.2: TYPICAL BATTERY CHARGING CURVE
4400 Series Installation and Operation Manual – 64527-008