5 Amp Projecta automatic solar charge controller

Protects your Battery from Solar Overcharge
Overcharging your battery occurs when the charge
going into the battery is unregulated. The solar
controller has a built in regulator to prevent batteries
from overcharging.
Maintains the Battery in a Fully Charged State
Any battery left unused will lose its charge over time. The solar controller can be connected indefinitely to the battery to keep the battery fully charged by using a process called floating. This means the controller will stop charging when the battery is full and will automatically start charging the battery as required.
Protects your Battery from Solar Power Discharge
Solar panels are known for converting the sun's energy into electric power; however less known is that solar panels can also drain power. The solar controller prevents the solar panel from draining power out of the battery.