Simple battery charging and discharging automatic control device circuit

For some batteries used to power fixed equipment, if an automatic control device as shown in Figure 10-20 is installed,
maintenance work can be greatly facilitated. When the battery is discharged to a specified value, the device can automatically disconnect the load to stop power supply, and switch to the charger to
charge the battery; when the battery is charged to a specified value, it will automatically stop charging and connect the load to power supply.
    In the figure, the relay
KA can be a JQX-4F type, DC 12V sensitive relay. It can pull in when the working voltage exceeds 8V , so there is no need to worry about the relay not being able to pull in when the battery voltage is 11. SV.