Precautions For Installation Design; Battery Installation Environment And Number Of Batteries; Installation Environment - Liebert NXC 30kVA User Manual

46 Chapter 6 Battery
Besides, the valve-regulated battery is not maintenance free. The valve-regulated battery must be kept clean, and it
shall be inspected regularly to check if the connection is reliable, and if it is corroded. For details, please refer to 6.11
Battery Maintenance.
It is suggested to connect no more than 4 strings of batteries in parallel. Batteries of different types, names or newness
shall not be used together. Otherwise, the battery inconsistency will cause frequent over-discharge or under-charge of
certain battery. At last, the battery will have premature failure, and the entire string of battery will have insufficient
backup time.
The battery must be stored in fully charged state. The battery will lose certain capacity because of self discharge
during the transportation or storage. Charge the battery before use. During the storage, ensure that the ambient
temperature shall not exceed the range of -15°C ~ +45°C, and the optimal temperature is 20°C ~ 25°C. To
compensate for the self discharge of the battery during the storage, the battery shall be charged every 3 months
during the storage. The specific time may differ for different batteries. For details, refer to the requirement of the
battery manufacturer.
It is very important to fully charge the battery before carrying out onsite test on the battery backup time. The test may
take several days. Therefore, it should be conducted after the battery has been subject to uninterrupted float charging
for at least one week.
When the battery has been running for several weeks or subject to two to three charge and discharge cycles, the
battery performance will be increased.
To avoid the battery over-charge or under-charge, please set the battery management parameters according to the
equalizing/float charge voltage and temperature compensation factor specified in the manuals provided by the battery
manufacturer. Please charge the battery immediately after discharge.

6.4 Precautions For Installation Design

Precautions for installation, use and maintenance of the battery are described in the relevant battery manual provided by the battery
manufacturer. The safety precautions described in this section include the important matters that must be considered during the
installation design. The design results may be changed according to the local situations.

6.5 Battery Installation Environment And Number Of Batteries

6.5.1 Installation Environment:

Fresh air volume (EN50272-2001)
The operating environment of the battery must be ventilated. During the operation of the battery, the following
requirement for the fresh air ventilation shall be satisfied:
Q=0.05×n×Igas×Crt×10
Where:
Q―The fresh air ventilation volume per hour, the unit is m
n―Number of cells
Igas―The gas evolving current density under battery float charging or boost charge conditions, the unit is mA/Ah
Igas=1, under the float charging condition of 2.27V/cell
Igas=8, under the boost charge condition of 2.35V/cell
Crt―20hr battery rated capacity
Temperature
Type
Recommended
optimal
temperature
–3 3
[m /h]
Table 6-1 Ambient temperature range
Temperature
value
The ambient temperature for the battery operation shall not be too high or too low.
20°C ~ 25°C If the average operating temperature of the battery rises from 25°C to 35°C, the
service life of the battery will be reduced by 50%. If the operating temperature of the
Liebert NXC 30kVA And 40kVA UPS User Manual
Note
3
/h
Remark