Samlex Power SCC-30AB Manuel Du Propriétaire page 11

SECTION 3 |
PERCENTAGE OF
FULL CHARGE
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Table 3.3. State of Charge versus Standing Voltage – 12V Battery
Check the individual cell Voltages. If the inter cell Voltage difference is more than a
0.2V, the battery will have to be equalized. Please note that only the non-sealed /
vented / flooded / wet cell batteries are equalized. Do not equalize sealed / VRLA type
of AGM or Gel Cell Batteries (unless allowed by the manufacturer).
Battery Efficiency
A lead-acid battery has an efficiency of only 75% - 85%. The energy lost appears as
heat and warms the battery. This means that the Ampere Hour (Ah) energy required
to charge a battery to its full rated capacity will be approximately 120% to 130%
higher than the Ah capacity rating of the battery.
Depth of Discharge and Battery Life
The deeper a battery is discharged on each cycle, the shorter the battery life. Using
more batteries than the minimum required will result in longer life for the battery
bank. A typical life cycle chart is given in the Table below:
DEPTH OF DISCHARGE
% OF Ah CAPACITY
10
50
80
100
It is recommended that the depth of discharge should be limited to 50%.
Effect of Temperature on Lead Acid Batteries
The charging characteristics of the battery will vary with temperature. This is nearly
linear and the Voltage Coefficient of Temperature Change is normally taken as -3
mV to -5 mV / ºC / Cell. The charging voltage is required to be reduced and as the
temperature is decreased, the charging voltage has to be increased.
Description & Principle of Operation
STANDING VOLTAGE OF
12V NOMINAL BATTERY
12.63V
12.6V
12.5V
12.3V
12.2V
12.1V
12.0V
11.8V
11.7V
11.6V
= / < 11.6V
CYCLE LIFE OF
GROUP 27 / 31
1000
320
200
150
Table 3.4. Typical Cycle Life Chart
Cell Voltage (12V BATTERY
HAS 6 CELLS IN SERIES)
2.105V
= / < 1.93V
CYCLE LIFE OF
GROUP 8D
1500
480
300
225
SAMLEX AMERICA INC. | 11
2.10V
2.08V
2.05V
2.03V
2.02V
2.00V
1.97V
1.95V
1.93V
CYCLE LIFE OF
GROUP GC2
3800
1100
675
550