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Table 1.4.3 shows that a 100 Ah capacity battery will deliver 100% (i.e. full 100 Ah) capacity if it is slowly discharged
over 20 Hours at the rate of 5 Amperes
(50W output for a 12V inverter, 50 and 100W output for a 24V inverter and
200W output for 48V inverter)
. However, if it is discharged at a rate of 50 Amperes
(500W output for a 12V inverter,
1000W output for a 24V inverter and 2000W for 48V inverter)
then theoretically, it should provide 100 Ah ÷ 50 = 2
Hours. However, Table 1.4.3 shows that for 2 Hours discharge rate, the capacity is reduced to 50% i.e. 50 Ah. Therefore,
at 50 Ampere discharge rate
(500W output for a 12V inverter, 1000W output for a 24V inverter and 2000W for 48V
inverter)
the battery will actually last for 50 Ah ÷ 50 Amperes = 1 Hour.
1.4.13 STATE OF CHARGE (SOC) OF A BATTERY – BASED ON “STANDING VOLTAGE”
The “Standing Voltage” of a battery under open circuit conditions (no charger or load connected to it) can
approximately indicate the State of Charge (SOC) of the battery.
The “Standing Voltage” is measured after
disconnecting any charging device(s) and the battery load(s) and letting the battery “stand” idle for 3 to 8 hours
before the voltage measurement is taken.
Table 1.4.4 shows the State of Charge versus Standing Voltage for a typical
12V/24V battery system at 80°F (26.7ºC).
TABLE 1.4.4 SOC VERSUS STANDING VOLTAGE (TYPICAL FLOODED BATTERY)
Percentage of
Full Charge
Standing Voltage
of Individual Cells
Standing Voltage of
12V Battery Pack/ Bank
Standing Voltage
of 24V Battery Bank
Standing Voltage
of 48V Battery Bank
100%
2.105V
12.63V
25.26V
50.52V
90%
2.10V
12.6V
25.20V
50.40V
80%
2.08V
12.5V
25.00V
50.00V
70%
2.05V
12.3V
24.60V
49.20V
60%
2.03V
12.2V
24.40V
48.80V
50%
2.02V
12.1V
24.20V
48.40V
40%
2.00V
12.0V
24.00V
48.00V
30%
1.97V
11.8V
23.60V
47.20V
20%
1.95V
11.7V
23.40V
46.80V
10%
1.93V
11.6V
23.20V
46.40V
0%
= / < 1.93V
= / < 11.6V
= / < 23.20V
= / < 46.40V
Check the individual cell voltages / specific gravity. If the inter-cell voltage difference is more than a 0.2V, or the
specific gravity difference is 0.015 or more, the cells will require equalization. Refer to Section 1.4.3.4 and 1.4.4
regarding details on equalization).
Please note that only non-sealed / vented / flooded / wet cell batteries are
equalized. Do not equalize sealed / VRLA type of AGM or Gel Cell Batteries.
1.4.14 STATE OF DISCHARGE OF A LOADED BATTERY – LOW BATTERY / DC INPUT VOLTAGE
ALARM AND SHUTDOWN IN INVERTERS
Most inverter hardware estimate the State of Discharge of the loaded battery by measuring the voltage at the
inverter’s DC input terminals
[considering that the DC input cables are thick enough to allow a negligible voltage drop
between the battery and the inverter]
.
SECTION 1.4 |
General Information
–
Battery Related
Содержание Evolution EVO-4248SP
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