Dual Micro USB 3.7v to 5V 2A Power Bank DIY 18650 LiPo Charger

The DD30CRTA is a PWM switch-mode battery charger controller for a 12V lead-acid battery in a small package using a 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.

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 the input voltage is lower than the battery voltage.