Fixed Over-Charge Voltage
Automatic Conditioning of Deeply Discharged Batteries
Battery Overvoltage Protection
Suitable for 1-10000AH 12V Lead-Acid Battery charger
1. The DD30CRTA is a PWM switch-mode battery charger controller for 12V lead-acid battery in a small package using few external components.
The DD30CRTA is specially designed for charging 12V lead-acid battery with trickle charge, constant current charge, over-charge and float charge mode.
In over-charge and float charge mode, the regulation voltage is internally set.
The constant charge current is programmable with a single sense resistor.
2. Deeply discharged batteries are automatically trickle charged at 17.5% of the programmed
constant charge current until the cell voltage exceeds 75% of the regulation voltage in
over-charge mode. The over-charge is terminated once the charging current drops to 38% of the
constant charge current, then DD30CRTA will enter float charge mode. A new charge cycle
automatically restarts if the battery voltage falls below 83.95% of the over-charge voltage in
float-charge mode. DD30CRTA will automatically enter sleep mode when input voltage is lower than battery voltage.
Other features include undervoltage lockout and indication, etc.
3. The Regulation Voltage in Over Voltage Mode and Float Charge Mode
The regulation voltage VOC at BAT pin in over charge mode is set at 14.8V(Typical) with ±1.5% accuracy.
In float charge mode, the regulation voltage VFLOAT at BAT pin is 91.57% of that in over charge mode, which is 13.55V(Typical).
Trickle Charge Mode At the beginning of a charge cycle, if the battery voltage is below 75%×VOC, the charger goes into trickle
charge mode with the charge current set at about 17.5% of the constant current.
4. End-of-Over Charge Current
When the battery voltage approaches the over-charge voltage, the charger goes into the over charge mode. In
over charge mode, the charge current start to decrease and when the charge current drops to 38% of constant
charge current, the charger goes into float-charge mode.
5. Float Charge Mode
After the over voltage charge is terminated, the charger goes into float charge mode. In float charge mode, the
battery voltage is regulated to 91.57%×VOC, namely 13.55V(Typical). Float charge mode can compensate for
the loss of battery power due to self-discharge or external loading.
6. Automatic Battery Recharge
In float mode, if both the battery and the input power supply (wall adapter) are present, a new charge cycle will
begin if the battery voltage drops below 83.95%×VOC due to self-discharge or external loading.
A new charge cycle can also be started manually by plugging off the input supply and reapplying it.
3 x 3A 12V 1-1000AH Lead-Acid Battery Charger