MPPT Charge Controllers: what is MPPT and its advantages

MPPT Charge Controllers or Maximum Power Point Tracking Charge Controllers are a type of charge controllers that track the power for the maximum power point.

What is an MPPT Charge Controller?

The MPPT charge controller ensures that the loads receive maximum current to be used (by quickly charging the battery).Maximum power point could be understood as an ideal voltage at which the maximum power is delivered to the loads, with minimum losses.This is also commonly referred to as peak power voltage.

What is the maximum power point (MPP)?

The maximum power point (MPP) describes the point on a current voltage (I-V) curve at which the solar PV device generates the largest output i.e. where the product of current intensity (I) and voltage (V) is maximum.The MPP may change due to external factors such as temperature, light conditions and workmanship of the device.In order to ensure maximum power output (Pmax) of a solar PV device in view of these external factors, maximum power output trackers (MPPT) may be operated to regulate the resistance of the device.

How do MPPT charge controllers work?

Anyone familiar with the charging and discharging characteristics of the battery is familiar to the fact that the voltage of the battery varies with its charge content.As current flows from a high potential to low potential, the steeper the gradient or voltage difference, the greater is the flow of current.This potential gradient could be made steeper by two ways:
  1. By increasing the output voltage of the Solar Panel
  2. By decreasing the voltage of the battery (discharging the battery)
[caption id="attachment_4817" align="aligncenter" width="551"]MPPT Charge Controller - Maximum Power Point MPPT Charge Controller - Maximum Power Point[/caption]

Using increased panel voltage to deliver maximum power

Now batteries could only be charged if the output voltage of the solar panel is greater than that of the batteries, to facilitate a flow of current from the panel to the battery.The output voltage of the panel depends on different factors, including the weather (irradiance). On a sunny day the output voltage may be higher than the rated output voltage, while during a cloudy day the output voltage is probably less.Normal controllers do not have the capacity to utilize this higher output voltage to deliver more power. However MPPT charge controllers have the ability to adjust the voltage in order to get a boost of current during times of peak demand.MPPT delivers higher than rated charge to the battery as they can adjust the voltage to current ratio.

Using battery voltage for delivering maximum power

Current and Voltage are inversely proportional to each other. With other words, if the current increases, the voltage drops and vice versa.By lowering the current by introducing some resistance in the path of the current, the MPPT charge controller can boost up the voltage.This voltage to current ratio adjustment is called Maximum power point tracking. MPPT typically increases the current to the battery by approximately 25% to 30%.Important to keep in mind is that a 80% discharged battery will charge faster than a 50% discharged battery.The reason for this is that when the battery starts to discharge, its voltage also reduces. The larger the gap between the solar panel output voltage and the battery voltage, the more current will flow into the battery, and the faster the battery will be charged.

Combined techniques for optimum battery charging

MPPT charge controllers use both principles mentioned above to deliver the maximum amount of power.This type of solar charge controllers come pre-programmed with adjustable set-points which can be edited and adjusted according to your needs.If you need to choose between a standard and a MPPT charge controller, usually paying a bit more for a proper MPPT controller is the way to go.
Njuba
By

Njuba

on 18 Dec 2019

I have a system of 450w solar module, which MPPT charge controller size can i use

Azli
By

Azli

on 28 Jun 2019

Good day...a situation, I had 3 series of 300Watt PV panel (Vmp=30.2V, Imp 10.2A). First time tested with MPPT inverter found only around 50watt being charge to the battery (at that time the battery is almost fully charge). As I assume that should be around 900W (for 3 panels). Is it because the MPPT controlled/limited the input power from PV panel because battery nearly fully charged? Need clear on this. Thanks id advance.

Bob B
By

Bob B

on 08 Mar 2019

If my panel is putting out 29 voc, will an mppt controller work on two 6v batterries without frying my batterries?

Jayanta bhuyan
By

Jayanta bhuyan

on 13 Jul 2018

For a300wp panel., 60voc is it suitable to charge 48volt battery system with 100amh but using mppt

akinmade temitope
By

akinmade temitope

on 24 Mar 2017

can I connect MPPT in 48volt why by batteries are connected in 24volt.

Danladi A. Birdling
By

Danladi A. Birdling

on 20 Aug 2018

Yes you can

ADR
By

ADR

on 03 Jan 2022

Can the MPPT controller be connected to just a resistive load and no batteries? The idea is to feed at max. eff. the resistive load but just when the irradiation is available.

Darrell
By

Darrell

on 18 Apr 2022

Can Mppt connect a 48v solar panel to charge a 12v battery?

Jon Stivers
By

Jon Stivers

on 25 Jan 2023

I want to know in detail how a MPPT controller works, not just the results. What is going on inside?

Steve
By

Steve

on 26 Feb 2023

MPPT chargers use an electronic controller that constantly monitors the output of the solar panel and adjusts the load on the panel to keep it operating at the MPP. This is achieved by varying the voltage and current levels to find the point at which the

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