This solar charge control combines multiple features into a single design: 3A current rating, low dropout voltage (LDO), range of voltage adjustment (accommodates 6 & 12V lead-acid batteries), reverse polarity protection, low parts cost ($5.90) and low parts count (14 components). High performance is attributed to the application of the common LM358 op amp and TL431 adjustable shunt voltage regulator.
Specifications
Solar Charge Control Circuit Schematic
Specifications
- Max solar panel rating (12V): 43W (open circuit solar panel voltage = 18 to 20V)
- Max solar panel rating (6V): 22W (open circuit solar panel voltage = 9 to 10V)
- Maximum input voltage: 36V
- Output voltage range: 4.5 to 15V (continuously adjustable)
- Max power dissipation: 17W (includes power dissipation of D3)
- Typical dropout voltage: 0.7V @ 3A (less @ lower currents)
- Maximum current: 3A (current limiting provided by solar panel characteristics)
- Voltage regulation: 5mV (voltage change no load to full load)
- Battery discharge: 100µA (most commercially units discharge at typically 5mA)
- Reverse battery protection: Control shuts down if battery is inadvertently connected reverse
Solar Charge Control Circuit Schematic
