Alpha Technologies Lomain Ni-Cd Pocket Plate Battery - Manual (Page 23)

23 745-680-B10-001 Rev. A
5.0 Sizing method for Standby Applications, continued
5.6 Floating effect -Voltage depression
When a Ni-Cd battery operates at a fixed floating voltage over a certain period of time,
a decrease of the voltage level of the discharge curve occurs. It begins after one week
and reaches its peak in approximately 3 months. Since this effect reduces the voltage
level of the battery it can be considered as reducing the performance and autonomy of
the battery. Therefore, it is necessary to take this effect into consideration when sizing a
Lomain Ni-Cd battery. The calculation program allows this factor to be included into the
customers´calculation. The floating effect is a reversible effect and can only be eliminated by
a full discharge/charge cycle. Please note that it cannot be prevented by just a boost charge.
The battery sizing program provides the option to calculate with and without this floating
effect so that the customer is able to see the added values. Our recommendation is always to
include this factor when sizing a battery.