SOLAR Charge Controller

Charge controller circuitry may be located in the battery-powered device, in a battery pack for either wired or wireless (inductive) charging, inline with the wiring, or in the AC adapter or other power supply module

Charge controller circuits are used for rechargeable electronic devices such as cell phones, laptop computers, portable audio players, and uninterruptible power supplies, as well as for larger battery systems found in electric vehicles and orbiting space satellites.

 Integrated charge controller circuitry
Circuitry that functions as a charge regulator controller may consist of several electrical components, or may be encapsulated in a single microchip, an integrated circuit (IC) usually called a charge controller IC or charge control IC.

Simple charge controllers stop charging a battery when they exceed a set high voltage level, and re-enable charging when battery voltage drops back below that level. Pulse width modulation (PWM) and maximum power point tracker (MPPT) technologies are more electronically sophisticated, adjusting charging rates depending on the battery's level, to allow charging closer to its maximum capacity. Charge controllers may also monitor battery temperature to prevent overheating. Some charge controller systems also display data, transmit data to remote displays, and data logging to track electric flow over time.

A series charge controller or series regulator disables further current flow into batteries when they are full. A shunt charge controller or shunt regulator diverts excess electricity to an auxiliary or "shunt" load, such as an electric water heater, when batteries are full.

Stand-alone charge controllers
Charge controllers are sold to consumers as separate devices, often in conjunction with solar or wind power generators, for uses such as RV, boat, and off-the-grid home battery storage systems. In solar applications, charge controllers may also be called solar regulators.

The terms "charge controller" or "charge regulator" may refer to either a stand-alone device, or to control circuitry integrated within a battery pack, battery-powered device, or battery recharger.

A charge controller or charge regulator limits the rate at which electric current is added to or drawn from electric batteries. It prevents overcharging and may prevent against overvoltage, which can reduce battery performance or lifespan, and may pose a safety risk.
It may also prevent completely draining ("deep discharging") a battery, or perform controlled discharges, depending on the battery technology, to protect battery life.It has great importance in the solar electric system. It prevents the battery from being over-charged and over-discharged and also prevents the electricity from being over-used for long as is determined by the system, which in turn enhances the life span of the battery and the battery too remains safe and sound. There are the + and plugs to connect the wires with the panel, battery and load in the charge controllers provided by Dhaulagiri Solar and Electronics Company Pvt. Ltd. 
There are signs that show whether the panel is charging or not, on/off button, battery low indicators etc. in the charge controller. Also in it are the 6 volt Radio-Cassette Player, the charging status of the Battery, Fuse Holder etc.