30
18. Charging
Select such battery types as SLD/FLD/GEL/USE, and select the
appropriate system voltage.
As shown in Fig. 18-1, the charging stages of lead-acid battery are:
MPPT charging, constant voltage charging (equalizing/boost/floating
charging), and current-limiting charging.
The constant voltage charging is divided into three stages: equalizing
charging, boost charging and floating charging
[MPPT charging] When the battery voltage has not reached the
target constant voltage value, the controller will perform MPPT
charging. When the battery voltage reaches the constant voltage
value, it will automatically exit MPPT charging and switch to constant
voltage charging (equalizing/boosting/floating charging).
[Equalizing charging] Regular equalizing charging is good for some
batteries. Equalizing charging is mainly to make the charging voltage
of battery higher than the standard supplementary voltage, besides,
it can vaporize the battery electrolyte to balance the battery voltage
and complete relevant chemical reaction. Equalizing charging and
boosting charging are not repeated during one full charging to avoid
excessive gas evolution or overheating of the battery.
Notes:
1) Since the equalizing charging of floored lead-acid battery produces
explosive gas, the battery compartment must be well ventilated.
2) Although the equalizing charging elevates the battery voltage, it
may damage the level of sensitive DC loads, therefore, it is necessary
to verify that the allowable input voltage of all loads in the system is
greater than the set battery voltage value in equalizing charging.
18-1: Charging of lead-acid battery
Charging voltage
Constant
voltage
charging
Floating
charging
Equalizing charging voltage
MPPT
Boost charging voltage
Floating charging voltage
Charging reconnect voltage
Time
Time
Fig. 18-1 Charging curve of lead acid battery
To Next Page
Loading...
Need help?
General
