ST – II Series POWER SUPPLIES
USER INSTRUCTIONS
Battery Management
To maintain the battery in a good state of health an intelligently controlled charging algorithm is
used. The purpose is to ensure that the correct voltages are applied to the battery terminals at the
appropriate times throughout it’s usage cycle.
To prevent corrosion on the battery positive plate due to continuous float charging current (VFloat
= 13.65V), the unit utilises a storage mode voltage (VStore = 13.25V) when no activity on the
battery is detected. This extends the battery life. During store mode, the unit exits to boost mode
(VBoost = 14.05V) for 15 minutes every 24hrs to maintain charge in the battery. If battery activity
is detected during store mode it exits automatically into float mode.
For any decision making involving the “loss of mains” detection there is a 2 minute mains debounce
period where there must be no mains signal present on the mains detect input for the “no mains”
signal to be valid.
A detailed description of the operational requirements for the charging algorithm is described
below:
Present Output
Set Voltage
Conditions Required to
Enter Operational State
Operational State
New Output Set
Voltage
N/A
Microcontroller first power
up.
Initial application of power
to the microcontroller
either from 240VAC mains
input or connection of a
battery to the battery input
(Includes Auxiliary power).
Vfloat
Vfloat (No Mains
Input)
Mains input detected after
loss of mains for less than
1 hour.
Float charging mode with
mains input voltage
detected (set 24 hour
timer).
Vfloat
Vboost
Mains input voltage was
detected for more than 15
minutes.
Float charging mode with
mains input voltage
detected (set 24 hour
timer).
Vfloat
Vfloat
No mains input voltage is
detected.
Float charging mode with
no mains input voltage
detected (set 1 hour timer).
Vfloat (No
mains input)
Vstore
No mains input voltage is
detected.
Float charging mode with
no mains input voltage
detected (set 1 hour timer).
Vfloat (No
mains input)
Periodic_Vboost
No mains input voltage is
detected.
Float charging mode with
no mains input voltage
detected (set 1 hour timer).
Vfloat (No
mains input)
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