I want to make my own solar lead acid battery charger and charge monitor. Any circuit and idea/ suggestions ? Answered
Requirement: Simple Charge Controller with Low Voltage Protection
For 6V Battery:
Solar Panel Open Circuit Voltage: 10.1 V (6V, 5W panel)
1. When battery is charging we require a "orange LED" to glow, as an indication of charging.
2. When battery reaches 7.2 V or above, a green LED shall glow indicating full charge. Additionally, the circuit should be capable of disconnecting the panel from battery (Simple PWM based).
3. When the battery reaches 5.2 V, a red LED shall glow indicating low voltage. Along with the red LED indication, we require a sound indication "beep", to alert the user to switch off the lamp. The interval of beep shall be between 5-10 seconds. Additionally, the load should be cut off from the battery, when the battery reaches 5.0 V. The battery low indicator (red LED) should glow only when the load is on. When the load is cutoff, even the red LED and the beep should be off. The load shall be reconnected only when the battery reaches a voltage of 6V.
4. A USB female port with 6V output for mobile charging is also required in the circuit.
For 12V Battery:
Solar Panel Open Circuit Voltage: 20.1 V (12V, 10W panel)
The requirements are similar to 6V battery circuit with the following changes:
Battery full indication: 14.8 V
Battery Low indication : 11.2 V
Load Cutoff Voltage : 10.8 V
Load Reconnect Voltage : 12.0 V
USB output is same at 6.0 V
using very simplest micro controller like 12F675 or cheapest/easily available on market.?