MPPT VS PWM Solar Charge Controller - Which One is Better For Me


The size of the sun based energy framework is vital to pick charge controller. MPPT solar charge control gadgets are awesome for proficient applications. PWM solar charge controllers can give adequate execution in little applications which needn't bother with more property. The effectiveness distinction among PWM and MPPT solar charge controllers may not be adequate to legitimize the value contrast in little undertakings. Nonetheless, in large undertakings, it assumes an enormous part regarding how well the framework execution.

PWM represents Pulse Width Modulation. PWM solar charge controllers can be clarified as an electrical switch between batteries. The switch can be rapidly turn on and switch off. Subsequently, wanted voltage can be gotten to charge the batteries. The charge current will be gradually diminished as the batteries charged. With a PWM charge controller, a 12-volt sunlight based charger is expected to charge a 12-volt battery, etc. On the off chance that you utilized a PWM charge controller of a 12V battery however with 48V sunlight based chargers, the PWM won't reap the additional energy delivered, it will just collect 12V. Purchasing a PWM charge regulator isn't really a terrible decision despite the fact that it is less proficient than a MPPT. The best charge regulator for you is a top notch one that works for the circumstance you really want it for, which we will cover underneath to assist you with choosing.

MPPT represents Maximum Power Point Tracking. MPPT is a procedure to notice and manages the energy going from sunlight powered charger to the batteries. Sunlight powered chargers show alterable results as indicated by climate conditions. MPPT charge controllers can coordinate the sunlight powered charger voltage with battery voltage to boost the charge proficiency. In these frameworks, the full force of sunlight powered chargers can be utilized by adjusting among voltage and current as per the P = V x A condition. For instance, the measure of current drawn from the boards decreased to ensure the voltage when the climate is overcast. At the point when the climate is bright, it is permitted to draw more current. When utilizing a MPPT solar charge controller, you can utilize a voltage sun oriented exhibit that is higher than your battery framework on the grounds that your charge regulator will decrease the voltage so it doesn't overpower your battery. Assuming you need better effectiveness and are burnt out on stressing over the contrast between your battery and sun powered charger voltage, put resources into a MPPT charge regulator. You simply need to ensure that the VOC of your boards is under the allowed voltage of your charge regulator.

Some Main Differences Between MPPT and PWM 


PWM Charge Controller

MPPT Charge Controller

Temperature ConditionsLess 20 – 25% chargingbetter suited for colder conditions
SizeOperates at a relatively constant harvesting efficiencyLess efficient in low power applications.
CostCheaperMore expensive

Array Voltage

PV array & battery voltages should match

PV array voltage can be higher than battery voltage

Battery Voltage

Operates at battery voltage so it performs well in warm temperatures and when the battery is almost full

Operates above battery voltage so it is can provide “boost” in cold temperatures and when the battery is low.

System Size


Typically recommended for use in smaller systems where MPPT benefits are minimal

≈ 150W – 200W or higher to take advantage of MPPT benefits

Off-Grid or Grid-Tie

Must use off-grid PV modules typically with Vmp ≈ 17 to 18 Volts for every 12V nominal battery voltage

Enables the use of lower cost/grid-tie PV Modules helping bring down the overall PV system cost

Array Sizing Method

PV array sized in Amps (based on current produced when PV array is operating at battery voltage)

PV array sized in Watts (based on the Controller Max. Charging Current x Battery Voltage)

Type of Solar ModuleNo support Tracks the maximum power point (thus MPPT) of these less expensive grid-tie modules in order to charge the batteries

Why Solar Charge Controller?

A solar charge controller is like a standard battery charger, for example it controls the current moving from the sun powered charger into the battery bank to try not to cheat the batteries. (In case you don't have to comprehend the why's, look as far as possible for a basic stream outline). Likewise with a customary quality battery charger, different battery types are obliged, the assimilation voltage, float voltage can be selectable, and at times the time-frames as well as the tail current are additionally selectable. They are particularly appropriate for lithium-iron-phosphate batteries as once completely energized the regulator then, at that point, stays at the set float or holding voltage of around 13.6V (3.4V per cell) for the rest of the day.

The most widely recognized charge profile is a similar essential grouping utilized on a quality mains charger, for example mass mode > retention mode > float mode. Passage into mass charge mode happens at:

* Dawn toward the beginning of the day
* In case the battery voltage dips under a characterized voltage for in excess of a set time-frame, for example 5 seconds (reemergence)

This reemergence into mass mode functions admirably with lead-corrosive batteries as the voltage drop and hang is more regrettable than it is for lithium-based batteries which keep a higher more steady voltage all through most of the release cycle.

Which One Should I Buy?

The PWM is a decent minimal expense choice:

• For more modest frameworks
• Where the effectiveness of the framework isn't basic, e.g stream charging.
• For sun powered chargers with a most extreme power voltage (Vmp) of up to 18V for charging a 12V battery (36V for 24V battery, and so forth)

The MPPT regulator is ideal:

• For bigger frameworks where the extra 20%* or more energy gathering is advantageous
• At the point when the sun oriented exhibit voltage is generously higher than the battery voltage for example utilizing house boards, for charging 12V batteries

* A MPPT regulator will yield more significant yields contrasted and a PWM regulator as the board voltage increments. For example a 160W eArche board utilizing 36 customary monocrystalline cells with a greatest power amp of 8.4A will give around 8.6A at 12V; while the 180W board having 4 additional cells will give a similar amperage however 4 extra cells expands the board voltage by 2V. A PWM regulator won't reap any extra energy, however a MPPT regulator will collect an extra 11.1% (4/36) from the 180W board.

For similar rule, all boards utilizing SunPower cells with in excess of 32 cells require a MPPT charge regulator any other way a PWM regulator will reap a similar energy from 36, 40, 44 cell boards as it does from a 32 cell board.