Product Description
Manual_Grid_Power_FNC_en_V3_0
20
5.4.
Battery Charging Characteristic
In the temperature range from 10 °C up to 30 °C the battery system can be operated with
the charging voltages as given in the table below:
Charging voltage at 20 °C in V per cell connected in series
Cell performance
class according
to EN 60623
Single-stage
charging (IU)
2-stage charging
(IU0U),
float charging
2 - stage
charging (IU0U),
Boost charge
Temperature
compensation
in V/degrees/cell;
starting from 20 °C
L
1.55
1.45
1.55 … 1.60
-0.003
M
1.52
H
1.48
X
1.45
VR L
-
1)
1.42
1.57
VR M
1.40
1.55
1)
It is not recommended to use the single stage charging as charging characteristic for
grid|power FNC
®
VR cells, because you cannot achieve the advantages of the VR
technology (no water addition or filling is required over the service life).
If the operating temperature differ from the range mentioned above, it is recommended to
use a temperature compensated charging method.
The following diagram illustrates the charging voltage of each cell connected in series
depending on the temperature of the electrolyte monitored by the charger (constant voltage,
constant current characteristic, with current limitation).
1 = Float charge
2 = Boost charge
The following conditions are applicable to the characteristic shown:
Switch from float charge to boost charge:
The current permanently overshoots a value of I
20
= Cn/20h.
Switch from boost charge to float charge:
The current permanently undershoots a value of I
20
= Cn/20h.
Current limit I
5
= Cn/5h (recommended value, there may be deviations to higher or lower
values of current)
Charge v
ol
tag
e
[V
]
Temperature of the electrolyte [°C]
