C&D Technologies RS-1476 Standby Battery Vented Cell User Manual

Page 17

LEAD CALCIUM CELLS

Note: Applies to average cell voltage. Battery system voltage should be set at average cell voltage multiplied by the

number of cells in battery

CHARGE COMPLETION: The charge is complete when the lowest cell voltage is stable over three consecutive

hourly readings, the voltage of the lowest cell is within 0.05 V of the string average, and the specific gravity of the

cells are within +0.010/- .005 of the average of the string (see Part 4 section 1.3). The string charge current (amps)

should remain the same over a 3 hour period by the end of the initial charging period.
Note on the specific gravity of the cells - The electrolyte of the cells is set at the factory to the nominal specific

gravity +0.010/-0.005, at 77°F (25°C), with the electrolyte level between the high and low level lines as specified in

Part 4, section 1.3 of this manual.

Note: As the cell operates and the electrolyte is depleted and replenished, and the state of charge changes due

to usage of the battery leading to sulfation and/or stratification, the specific gravity of the electrolyte is impacted

accordingly and specific gravity measurements may not reflect the actual cell gravity. In such cases the use of the

string average specific gravity measurements is recommended in troubleshooting possible outlying cells versus their

shift from nominal. For a new cell following proper equalization methods the measured specific gravity should reflect

the factory requirements for nominal gravity on the initial float charge. Please reference to Part 4, Section 1.3.

1.2 Float charge
Standby batteries are continuously connected to control circuits which must be energized at all times. Connected

to a load in parallel with a continuously operating charger, these batteries assure instantaneous support of the

load in the event of a power failure or brownout. In addition to operating the connected load, the power supply

maintains the standby battery in a fully charged condition. This parallel interconnection and operation is called

float service.
For optimum service, adjust the charger to the float voltages shown in Table 5.

Table 5 - Float Voltage Per Cell (VPC)

LEAD-ANTIMONY CELLS

LEAD-CALCIUM CELLS

PART 2

CHARGING AND OPERATION OF BATTERY (CONTINUED)

Nominal Specific

Gravity

See Part 4, Sec. 1.3)

Maximum Average

Volts Per Cell VPC

(see note)

Time in Hours

at maximum

cell voltage

1.215

1.250

1.300

2.38

2.43

2.50

24 - 100

Nominal Specific Gravity

(See Part 4, Sec. 1.3)

Float Voltage Setpoint Range

77ºF (25ºC)

1.215

2.15 – 2.18

Nominal Specific

Gravity

(See Part 4, Sec. 1.3)

Float Voltage

Setpoint Range

77ºF (25ºC) (1)

Allowable

Individual Cell

Voltage Range

77ºF (25ºC) (2)

Applications

1.215

2.17 – 2.22

2.12 - 2.27

Telecom except LCT-HP,

MCTII and MCT-HP

1.215

2.20 – 2.25

2.12 - 2.29

UPS, Switchgear & Control (Utility),

LCT-HP / MCT II / MCT-HP

1.250

2.22 – 2.27

2.15 - 2.32

All

1.300

2.32 – 2.36

2.23 - 2.41

All

RS1476/0215/CD