Discharging; Discharge Characteristics - EnerSys Nexsys 12NXS26 Technical Manual

DISCHARGING

The valves on the top of the bloc must not be sealed or covered. Electrical connections (e.g.
plugs) must only be made or broken in the open circuit condition. Discharges over 80% of
the rated capacity are categorised as deep discharges and are not acceptable as they
reduce considerably the life expectancy of the bloc. Discharged blocs MUST be recharged
immediately and MUST not be left in a discharged condition.
Note: The following statement only applies to partially discharged blocs.
Discharged blocs can freeze.
Limit the discharge to 80% DOD. The presence of a discharge limiter is mandatory and cut-
off voltage must be set at the value detailed in Table 4, when discharging with currents in
the range of I to I . At lower currents please seek advice from the EnerSys® Application
0.5 5
Engineering Authority.
Depth of Discharge
Table 4 - Cut-off voltage limits

DISCHARGE CHARACTERISTICS

The following table shows discharge characteristic of the NexSys® range to an end point
voltage of 1.75Vpc @ 25°C/77°F and 1.70Vpc @ 30°C/86°F. See Table 5 & 6 below.
Discharge Rate (Hr) 20
1.53
12NXS26
12NXS36 2.06
12NXS38 2.10
12NXS50 2.87
12NXS61 3.38
12NXS62
3.55
12NXS85 5.27
12NXS86 5.17
12NXS90
4.97
12NXS120 6.84
12NXS137
7.87
12NXS157
9.43
12NXS166
9.56
12NXS186
10.80
Table 5 – Constant Current discharge table @ 30°C/86°F
60%
80%
Constant Current Discharge (A) 1.7VPC @ 30°C/86°F
10 8
2.81 3.41
3.83 4.68
4.00 4.92
5.35 6.54
6.41 7.88
6.71 8.20
9.43 11.37
9.47 11.55
9.44 11.55
12.58 15.55
15.31 18.61
17.47 21.41
17.80 21.74
20.04 24.50
10
NexSys Technical Manual
Cut – off Voltage Setting (Vpc)
1.96 V
1.92 V
5 3
5.21 8.21
7.18 11.34
7.59 12.03
10.02 15.77
12.20 19.45
12.42 19.50
16.99 26.41
17.46 27.95
18.02 28.42
23.98 38.18
27.38 41.25
31.40 50.31
33.20 51.89
37.22 58.28
1
0.5
21.28 37.55
29.17 50.77
31.09 54.39
39.86 68.63
50.65 87.66
49.94 88.73
66.25 113.52
73.65 130.81
72.32 127.60
98.98 171.63
102.34 174.46
126.17 207.83
126.87 211.52
142.71 236.05