Solar charge controllers are required by most solar power
systems that involve the use of batteries. They work to regulate the power as
it moves from the solar panels to the batteries. A proper charge controller
will keep the batteries from being overcharged. The simplest kind of charge controller functions to monitor
the battery voltage and opens the circuit to stop the charging process when
voltage reaches a certain level. PWM extends battery life even more, as it
decreases stress on the battery.
The latest advancement in solar charge controllers is
maximum power point tracking, or MPPT. Most solar panels produce more voltage
than is needed by the batteries. An MPPT charge controller will also largely
eliminate the amount of power loss that a solar power system experiences.
Preventing reverse-current flow is another ability which certain modern charge
controllers possess.
Why Do I Need Solar Charge Controllers?
It is extremely important to have a solar charge controller
to protect your batteries from being overcharged. The output voltage of your
solar panels is constantly changing. PV charge controllers come in all shapes
and sizes. Easy to install, a PV charge controller is required in almost every
solar power systems that utilize batteries. Most solar panel controllers come
with either a simple LED or digital displays.
The current passing through the solar charge controller
charges the batteries used in various household items. At night or when solar
modules aren't generating any power, power can actually flow backwards from the
batteries to the solar modules, draining the batteries. The solar charge
regulator would ensure that this doesn't happen. If solar energy is not
actually passing from the solar panels to the circuit, it disconnects the solar
panels from the batteries and stops the reverse flow of current.
Because a charge controller enables you to monitor battery
charging, thus avoiding over or under-charging, then if you are planning an
on-grid system, you won't need a controller. If you are contemplating on
off-grid system using batteries, are planning to use solar and wind power in
the same system, or are merely planning a backup power source for outages-which
requires batteries-then you will need to choose a good charge controller for
your system.
Different Types of Solar Charge Controllers
There are several different basic types of charge
controllers, the first being the series cycling controller which is probably
the simplest; the series cycling controller prohibits overcharging of your
batteries simply by turning your solar panel's current off and on based on the
battery voltage. If the battery voltage is to nearly full charge, a mechanical
relay on the controller shuts off the charge. When the battery voltage begins
to fall and gets low enough, the charge controller kicks back in.
The constant voltage controller goes through bulk charge
first, which allows the power to go straight from the solar panels to the
batteries until they are charged. The second stage is called the absorption
stage which holds the maximum battery voltage by reducing the charge current.
Float charge is the third stage and occurs when the battery voltage is reduced
once the charge is complete. The constant voltage charge controller avoids
excessive evaporation of battery water, thus extending the life of your
expensive batteries. If you are using sealed, AGM or gel batteries, the
three-stage constant voltage controller would be the best, safest method of
charging your system.
