FIAMM Industrial Batteries
December 2012
FIAMM AGM Valve Regulated Recombination Batteries: FLX Series- Engineering Manual
This document and any confidential information it contains shall be distributed, routed or made available solely with written permission of
FIAMM. FIAMM reserves the right to change or revise without notice any information or detail given in this manual Page
8
To reduce the recharge time, the IU recharge method can be used with a maximum voltage of 2.30
V/cell at 68-77° F for 24 hours. Current should not be over 25% of nominal capacity, especially in sites
where temperature may exceeds 86° F to avoid thermal runaway, overheating or overcharging of the
batteries.
For very deep cyclic applications recharge voltage should not be higher than 2.30 V/cell for 16 to 24 hrs
after every discharge.
Temperature compensation of the float voltage
.
To optimize FIAMM
FLX
battery life and performance over the normal operating temperature range, the
float voltage should be adjusted in accordance with table 4.
In environments where temperature fluctuations are very limited, float voltage can be adjusted manually
as needed. For most sites without a climate control systems it is advisable to have batteries connected
to a charger with a built-in temperature compensation circuit.
Temperature sensor needs to be positioned on or over the batteries and not in the charger.
Ripple
Excessive ripple currents can cause battery overheating, which will lead to shorter life expectancy and
reduced product performance. It is recommended that voltage regulation across the system (including
the load, but with battery disconnected), under steady state conditions, should be better than
±
1%
through 5% to 100% load. Transient and other ripple type excursions can be accommodated provided
that, with the battery disconnected but the load connected, the system peak to peak voltage, including
the regulation limits, falls within
±
2.5% of the recommended float voltage of the battery. Under no
circumstances should the current flowing through the battery, when it is operating under float conditions,
reverse into the discharge mode.
4 STORAGE AND REFRESH CHARGING
Storage
Batteries are delivered filled and charged ready for installation. If they cannot be installed immediately,
batteries need to be kept in fresh, clean dry rooms.
Refreshing charge procedure
During storage batteries will lose part of their capacity due to self-discharge (2% per month at 77° F). A
freshening charge is recommended at least every 6 months (at 77° F storage temperature).
Batteries should be refreshed, even if kept in storage at 77° F, when the cell voltage drops below the
values listed in table 5. A freshening charge could be carried out by charging at 2.4 V/cell for about 24
hours at 77° F (boost). If the charging system can not meet the above requirement (lower than 2.4 Vpc,
it is necessary to extend the charging time 24 hrs for every 0.03V/cell lower than 2.30V/cell, for
example, 120 hours at 2.28 V/cell).
Table 5 – OPEN CIRCUIT VOLTAGE VALUES REQUIRING A RECHARGE (WHEN STORAGE AT 77° F)
RANGE
OPEN CIRCUIT VOLTAGE (PER CELL)
FLX
2 months
2.120
4 months
2.105
6 months
2.095
