Manual

11
745-680-B8-002, Rev. B
During operation, verify batteries are:
Float-charged in order to maintain a fully charged condition during the standby period.•
Completely recharged after a discharge. Recharge as soon as possible to ensure maximum protection •
against subsequent power outages. Early recharge also ensures maximum battery life.
While recharging procedures vary depending on the recharge time and battery life, generally charging is
performed as follows:
At a voltage equal to the oat voltage and a low current (long recharge time);•
At a voltage not higher than 2.4Vpc and a high current (faster recharge).•
The IU recharge method, also known as modied constant potential, has been used for many years and in
a variety of applications. It satises the need to have the battery quickly recharged while ensuring maximum
battery life.
Recharge at a constant current rate until the voltage reaches a pre-set value. 1.
Maintain the pre-set voltage and decrease the current until a minimum dened value is reached. 2.
Complete the recharge at a nal constant voltage value equal to or less than that dened for oat charge 3.
and decrease the current to the value used in oat.
The equation to determine oat voltage at a given temperature is:
V = 2.32 – 0.0025 * T
V = Float Voltage
T = Temperature
or
-2.5 mV per 1.8ºF (1ºC) temperature uctuation outside of 68ºF (20ºC)
The minimum and maximum recommended voltages are 0.010V on either side of the determined
voltage at a given temperature. Batteries oated at voltages above the range will have an increased
risk of dry out, grid corrosion and thermal runaway. Batteries oated below the range will not receive
enough charge, and will be subject to sulfation.
Temperature ºF (ºC) Recommended Float (Vpc)
-4 (-20) 2.37
32 (0) 2.32
68 (20) 2.27
77 (25) 2.26
140 (60) 2.17
2.1 Float Charge
2.27V at 68ºF (20ºC) is the recommended voltage for oat charge. This voltage ensures the
maximum life of SMU-F batteries. These batteries can operate over a temperature range of -4ºF
(-20ºC) to +140ºF (+60ºC). Performance and life are greatly reduced outside of this temperature
range.
Table 2-1, Float Voltages
NOTE:
Refer to your particular charger’s manual for specic instructions regarding charger setup and operation.
2.0 Charging