User's Manual

Doc. No.
Rev.
Date
DRAFT
1.01
2012-01-27
Damm Cellular Systems A/S, Denmark
TetraFlex
®
7.5 Manual - BS41x
TetraFlex® 7.5 Manual 1-31
The battery lifetime is a critical parameter. High quality back-up batteries normally have a
specified lifetime of 10-15 years at normal room temperature.
The batteries should also be of the gas-tight type when co-located with the BS to avoid
corrosive gases, which may damage the electronics.
A battery capacity of 48V 50Ah would be a typical choice for a 4-carrier BS. The picture
below shows an example of such a battery.
The following estimated back-up times is being achieved with a 50Ah battery (weight about
130kg):
Note that for higher load current the efficiency of the battery drops considerably below the
100%.
For the 8-carrier Base Station a 100Ah battery could be considered (weight about 250kg).
1.3.8.3 External battery installation
The connections needed for the battery attachment is shown on the schematics below
Base Station size
Current
Backup time
2-carrier
6A
8 hours
4-carrier
11A
4 hours
6-carrier
16A
2.5 hours
8-carrier
21A
1.8 hours