Battery Low Voltage Tolerances - Toshiba 4400 Series Installation And Operation Manual

13.6

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.
Charging Period
Period 1
Period 2
Period 3
CURRENT
I
CHARGE
(11.5A)
V
0
4400 Series Installation and Operation Manual – 64527-006
Initial charging at maximum current (limited by charger). V
minimum voltage at which the UPS will shut down power to the
load.
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.
VOLTAGE
CHARGING
CURRENT
= 324 V
MAX
V = 230 V
MIN
DISCHARGE
SHUT-OFF
POINT
0
PERIOD 1
FIGURE 13.2 – TYPICAL BATTERY CHARGING CURVE
Explanation
BATTERY
CHARGE
VOLTAGE
FULLY
CHARGED
PERIOD 2 PERIOD 3
is
min
TIME
93