Product Manual

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Figure 6: Charging Algorithm
Charging Algorithm
Float Mode Store Mode Periodic Boost Mode
During Float mode the battery is charged at
15 A until the float voltage is reached. Then it
changes to constant voltage charging.
If the float voltage has been reached and the
mains is interrupted for more than an hour, then
upon recovery of the mains the unit switches to
Boost mode for 15 minutes and then returns
back to Float mode.
Store mode is activated when the battery has
been in Float mode for 24 hours (long enough for
the battery to be fully charged).
During Store mode the unit switches to Boost
mode for 15 minutes every 24 hours (called
Periodic Boost mode).
During Periodic Boost mode if the mains is lost for
more than 2 minutes, then upon recovery of the
mains the unit switches to Float mode.
Figure 6: Charging Algorithm
Battery Charging Store Mode
During Float charging (typically at 13.65 V) there is continuous charging current
into the battery, sufficient in a long term charging situation to cause corrosion on
the battery positive plate. To prevent this corrosion the charger utilises what is
called a Storage mode, where the charging voltage is reduced to 13.25 V. In this
mode the charging current is very small, usually less than the battery's self-
discharge current.
If left continuously in Store mode, the battery would slowly discharge, so to
prevent this the charger switches to Boost mode for 15 minutes once a day. This
is sufficient to keep the battery fully charged.
The net result is a battery which can be left on charge indefinitely without the
usual battery degradation problems from continuous charging.
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When mains is interrupted
during Vfloat mode
When mains is interrupted
during Store or Periodic
Boost mode
15 min 24 Hours24 Hours
Vfloat
(13.65V)
Vstore
(13.25V)
Vboost
(14.05V)
Vstore
(13.25V)
24 Hours
Battery Voltage
BATTERY CHARGING STORE MODE
During Float charging (typically at 13.65 V) there is continuous charging current
into the battery, sufficient in a long term charging situation to cause corrosion
on the battery positive plate. To prevent this corrosion the charger utilises what
is called a Storage mode, where the charging voltage is reduced to 13.25 V. In
this mode the charging current is very small, usually less than the battery’s
selfdischarge current.
If left continuously in Store mode, the battery would slowly discharge, so to
prevent this the charger switches to Boost mode for 15 minutes once a day.
This is sufficient to keep the battery fully charged.
The net result is a battery which can be left on charge indefinitely without the
usual battery degradation problems from continuous charging.
BATTERY CHARGING 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 its usage cycle. The
basics of the charging algorithm are detailed in Figure 6.