Cheap MPPT Solar Battery Charger Circuit

The submit describes an inexpensive still useful, much less than $1 inexpensive yet useful solar charger circuit, which is often developed even by a layman for utilizing economical solar battery charging.

What exactly is highest efficiency solar tracking? For a layman this might be something too complicated and advanced to understand and a system concerning extraordinary electronics.

In a manner it might be correct and certainly MPPTs are complex high end devices which can be intended for optimizing the charging of the battery without changing the solar panel V/I curve.

In easy words an MPPT monitors the immediate optimum accessible voltage from the solar panel and adjusts the charging rate of the battery such that the panel voltage stays unchanged or far from loading.

Stated simply, a solar panel would certainly function most effectively if its highest situational voltage is not ripped down to the associated battery voltage which is being charged.

For instance, if the open circuit voltage of your solar panel is 20V and the battery to be charged is rated at 12V, and if you hook up the two instantly could cause the panel voltage to decrease to the battery voltage, which might create things too ineffective.

On the other hand if you could maintain the panel voltage unaltered yet remove the best suited charging option from it, could make the system work with MPPT theory.

So it’s exactly about charging the battery optimally without disturbing or reducing the panel voltage.

There’s one easy and zero cost procedure for applying the above circumstances.

Pick a solar panel whose open circuit voltage suits the battery charging voltage. Which means for a 12V battery you can find a panel with 15V knowing that would likely deliver optimum optimization of both the guidelines.

Nevertheless practically the above problems could possibly be hard to attain simply because solar panels never generate continuous outputs, and are likely to produce worsening power levels as a reaction to different sun ray positions.

That’s why constantly a higher rated solar panel is advisable to ensure that even under worse day time situations it maintains the battery charging.

With that in mind, in no way you are required to choose costly MPpT devices, you may get comparable outcomes by spending a few dollars for it. The following conversation could make the methods clear.

Steps to make a simple cheap MPPT Circuit

As mentioned above, in an effort to stay away from unneeded installing of the panel we should instead have circumstances preferably complementing the PV voltage with the battery voltage.

This can be achieved by utilizing a few diodes, a cheap voltmeter or your current multimeter and a rotary switch. Ofcourse at around $1 you can not assume it to be automatic, you might have to seek advise from the switch quite a few times each day.

We realize that a rectifier diode’s forward voltage decrease is about 0.6 volts, so by adding a lot of diodes in series it could be easy to identify the panel from obtaining dragged to the attached battery voltage.

Talking about the circuit digaram enumerated below, an awesome little MPPT charger could be organized utilizing the demonstrated low-cost parts.

Let’s believe in the diagram, the panel open circuit voltage to be 20V and the battery to be graded at 12V.

Hooking up them straight would certainly drag the panel voltage to the battery level making things improper.

By adding 9 diodes in series we efficiently segregate the panel from acquiring loaded and dragged to the battery voltage but without doubt take out the Maximum charging current from it.

The entire forward drop of the combined diodes could well be around 5V, plus battery charging voltage 14.4V provides around 20V, which means once associated with all the diodes in collection throughout peak sunshine, the panel voltage would probably fall slightly to might be around 19V resultant an effective charging of the battery.

Now think the sun commences dipping, leading to the panel voltage to decrease below the rated voltage, this may be checked across the linked voltmeter, and a few diodes skipped until the battery is renewed with obtaining maximum power.

The arrow symbol presented linked with the panel voltage positive could be restored with a rotary switched for the suggested choice of the diodes in series.

With the above circumstance applied, an obvious MPPT charging circumstances could be simulated successfully without using expensive devices. This can be achieved for any kinds of panels and batteries simply by which includes more variety of diodes in series.

The described cheap MPPT circuit might be in some way made automatic, you might refer to the following post to understand the automated type of the above discussed design.


simplest mppt solar charger circuit