Charge Controllers | MPPT | PWM

MPPT ( maximum power point tracking )
The MPPT Charge Controller is known for the ability to down convert voltage while up
converting the amps to give you as much as 30% more power from a solar array that is
normally lost when using a common or non MPPT controller. Example: A solar module with a
17.2 volt Vmp would be pulled down to the battery voltage If the battery was at 11.7 volts
using a common charge controller. A loss of 5.5 volts or 32%. If you had 1000 watts in solar
modules, you just lost 320 watts. That is about the price of 3 MPPT controllers.

PWM (pulse width modulation)
Helps to remove buildup on the plates in a battery extending a battery’s life.
- Pulse = Stop and start like with your heart beat, (Hammers the lead plates clean)
- Width = Time the pulse is turned on and time is the pulse is turned off.
- Modulation = Controls more or less volume of the charge.

All three of the above are used at the same time to charge faster and clean the plates.
When the battery is low on charge PWM will pulse longer with at a higher modulation. As the
battery fills up it will pulse shorter with a lower out power level

Solar Controllers are engineered to keep you from damaging your batteries.
This is done by adjusting the power from the source based on how much power is required
to bring the batteries up to full charge

Bulk,
Is normally the first step. In wet cell lead acid batteries it will allow enough / max power
through the controller to bring the voltage up to a set voltage. This will keep the acid water
mix bubbling and hold at this level for a set amount of time which is called the absorb stage.

Absorb stage,
Is a tapered charge which the solar energy controller will slowly taper down the amps as the
battery reaches full charge not allowing the battery charge to go over the bulk voltage limits.

Float,
The charge controller will auto switch to the float charge, which is a lower voltage closer to
the nominal battery voltage. During this stage as you use more power from the batteries the
unit will adjust the input amps up and down to hold this float voltage.

EQ (Equalize)
Is only used on wet cell batteries and is normally 1 volt higher then the bulk charge voltage.
Read your battery and charge controllers instructions before EQing your battery.