Simple Solar Battery Charger Circuits

It is well known pretty much about solar panels and their features. The simple abilities these particular awesome devices is to transfer solar energy or sun light into electricity.

Essentially a solar panel is comprised discrete parts of individual photo voltaic cells. Each one of these cells have the ability to produce a small magnitude of electrical power, generally around 1.5 to 3 volts.

Most of these cells over the panel are cabled in series in order that the total useful voltage produced by the whole unit mounts up to an workable 12 volts or 24 volts outputs.

The current created by the unit is instantly proportional to the level of the sun light incident over the surface of the panel.

The power produced from a solar panel is usually employed for charging a lead acid battery. The lead acid battery when completely charged is utilized with an inverter for getting the needed AC mains voltage for running the house electrical.

Preferably the sun rays ought to be incident over the surface of the panel for it to function optimally. In spite of this since the sun is never still, the panel ought to monitor or carry out the suns path continuously so that it produces electricity at an effective rate.

If you happen to be planning to create an automatic dual tracker solar panel system you might introduce one of my prior content. Without a solar tracker, the solar panel are able to do the conversions only at around 30 % effectiveness.

Returning to our actual conversations regarding solar panels, this device might be regarded the heart of the system as far transforming solar energy into electricity is concerned, in spite of this the electricity created needs a number of dimensioning to be achieved before it may be utilized efficiently in the earlier grid tie system.

The voltage obtained from a solar panel is rarely sturdy and differs significantly in line with the position of the sun and intensity of the sun rays and of course on the degree of occurrence over the solar panel.

This voltage if given to the battery for charging may cause damage and unneeded heating of the battery and the connected electronics; consequently may be harmful to the whole system.

To be able to control the voltage from the solar panel usually a voltage regulator circuit is employed relating to the solar panel output and the battery input. This circuit ensures that the voltage from the solar panel by no means surpasses the safe value needed by the battery for charging.

Generally to get most effective outcomes from the solar panel, the minimum voltage output from the panel needs to be more than the essential battery charging voltage, meaning even throughout unfavorable problems when the sun rays are not sharp or maximum, the solar panel still ought to be able to yield a voltage greater than say 12 volts which can be the battery voltage under charge.

Solar Voltage regulators readily available can be overpriced and not so dependable; on the other hand producing the kind of regulator at home utilizing normal electronic parts could be not just fun but additionally risk-free.

Talking about the offered solar panel voltage regulator, charger circuit we notice a design that makes use of very regular elements and yet satisfies the requirements in the same way essential by our specifications.

A single IC LM 338 turns into the heart of the whole configuration and evolves into sensibly for applying the preferred voltage regulations single handedly.

The demonstrated solar panel regulator, charger circuit is framed as per the normal mode of the IC 338 configuration.

The input is provided to the demonstrated input points of the IC and the output for the battery obtained at the output of the IC. The pot or the preset is employed to precisely set the voltage level that could be regarded as the safe value for the battery.

The circuit also provides a current control feature, helping to make sure that the battery constantly obtains a fixed fixed charging current rate and is in no way over powered.

The module could be connected as instructed in the diagram. The appropriate positions mentioned could be basically cabled even by a layman. Rest of the function is looked after by the regulator circuit.

The switch S1 ought to be toggled to inverter mode once the battery gets fully charged (as suggested over the meter).

The charging current might be chosen by properly choosing the value of the resistors R3. It is possible by solving the formula:

0.6/R3 = 1/10 battery AH

The preset VR1 is adjusted for obtaining the essential charging voltage from the regulator.

Automatic Solar Charger Circuit Single Transistor

In this post we discuss elaborately an automatic solar charger circuit using a single transistor relay circuit.

Simple Charger using a Battery and Solar panel
A solar panel can certainly be applied to directly charge a battery with virtually no other elements. Just hook up the panel with the battery and it can charge once the panel begins getting dazzling sunshine - offering the panel a voltage of minimum 30% to 50% more than battery power you might be charging.
Below is a few remarkable information:
The voltage from the solar panel is not important and the voltage of the battery really does not make a difference. You are able to hook up any solar panel to any battery - ensuring the solar panel constitutes a voltage minimum 30% to 50% higher than the battery you might be charging.

The output voltage of the solar panel may only adjust to the voltage from the battery. Despite the fact that there exists a voltage mis-match, there isn't any "missing" or thrown away energy.

A good 18v solar panel "runs into" a 12v battery using the optimum current it could possibly generate once the strength of the sunlight is a highest.
To avoid an excessive amount of mis-match, it is strongly recommended you keep the panel voltage to inside 150% of the battery voltage. (6v battery - 9v utmost solar panel, 12v battery - 18v optimum panel, 24v battery - 36v spork panel).
However below is the key factor: In order to avoid overcharging of the battery, the wattage of the solar panel is extremely important.
When the wattage of your 18v panel is 10watts, the current is 10/18 = 0.55 amps = 550mA.
To counteract overcharging a battery pack, the charging current must not be greater than one-tenth its amp-hr capacity.
In particular, a 2,000mAhr group of cells must not be charged at a level beyond 200mA for 14 hours. This can be referred to as its 14-hour rate.
Yet this rating can be a CONSTANT RATING as a solar panel delivers an output for approximately 8 hours each day, you are able to boost the charging current to 550mA for Eight hours. This may provide the power to completely charge the cells.
For this reason a 10 watt solar panel could be directly attached to a group of (practically fully discharged) 2,000mAhr cells.
For a 12v 1.2AHr battery, the charging current is going to be 100mA for 12 hours or 330mA for 4 hours along with a regulator circuit is going to be necessary to protect against overcharging.
For any 12v 4.5AHr battery, the charging current is going to be 375mA for Half of the day and a bigger solar panel is going to be necessary.

The Role of a Blocking Diode
Some solar panels may discharge the battery (a touch) while it isn't obtaining sunlight and a diode is usually included with to protect against self discharge.

This diode lowers 0.6v once the panel is working and can cut down the ideal current (somewhat) while the solar panel is charging the battery. In case the diode is Schottky, the voltage-drop can be 0.35v.
Some solar panels incorporate this diode - known as BYPASS DIODE.

How to Stop Overcharging

You will find a couple of methods to protect against overcharging the battery.
1. Discharge the battery practically thoroughly every night and make use of a solar panel which will mainly offer 120% of the amp-hour capacity of the battery the next day.
2. Put in a VOLTAGE REGULATOR.

Here is the most basic and least expensive regulator to charge a 12v battery.

The solar panel should have the ability to generate a minimum of 16v on NO LOAD. (25-28 cells). The diagram simply exhibits a 24 cell solar panel - it ought to be 28 cells.
The one other factor you need to think about is the wattage of the solar panel. This can count on how quickly you would like to charge the battery and/or just how much power you take out through the battery every day and/or the amp-Hr capacity from the battery.
As an example, a 12v 1.2A-Hr battery consists of 14watt-hours of electricity. An 6watt panel (16v to 18v) may give you 18watt-hours (in glowing sunshine) in Three hours. The battery will probably be totally charged in 3 hours.

Cheapest 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.

Solar Charger Using Flyback Converter

The publish evaluates a solar charger circuit including an I/V monitoring function for applying an effective battery charging operations.

A solar panel generally we understand is utilized for transforming sun rays into electricity, in spite of this when a immoderate load is associated with a solar panel its performance could easily get decreased significantly producing the whole system extremely ineffective.

An flyback converter when associated relating to the load and solar panel ensures that the load receives the best amount of energy without distorting the effectiveness of the solar panel.

Essentially a solar panel is simply another power supply whose performance almost always is dependent upon the utilization of its current(amps) properly.

According to the I/V monitoring graph of a solar panel, we observe that for as long as the voltage is not disrupted (lowered) the panel works over its highest power point zone, where it has the capacity to provide its highest rated current to the load.

Basically if the accessible optimum voltage of the panel is not slowed down by the load the panel proceeds to supply the optimum range of current to the attached load. This parameter evolves into solely essential with any solar panel, and a flyback topology in particular looks after this when employed with a solar panel a load.

On the other hand, it could be also thought that considering that the voltage is merely a function of the current, provided that the amps from the solar panel is recovered to an perfect point, the voltage does not need to get impacted therefore keeping the procedures within the maximum zone. This really is what's been executed in the mentioned design.

The suggested flyback solar charger circuit with I/V checking was created by me bearing in mind the above criticality of a solar panel.

Let's understand the information of the circuit by talking about the following diagram below:

Right here the IC 741 section is the current administering phase, the IC555 are set up as PWM optimizer while the BC547 phase is for creating an incrementing ramp.

When the circuit is operated up with a solar panel, the ramp generator begins generating a ramping voltage across pin5 of IC2 (555).
IC2 together with IC1 transforms this ramping voltage into in the same way increasing PWMs at a particular high frequency.
This PWM is used on a ferrite transformer primary winding via a N-channel mosfet.
The output of the ferrite transformer is properly filtered and built-in with the load or a battery which should be charged.
As the ramp and the related PWM rises, the battery commences getting the needed current.
This current (amp) intake rate by the battery is employed on the inputs of the I/V monitoring IC741 opamp phase by means of a rising voltage across Rx.
The voltage across Rx is found and checked by the inputs of the opamp.
While it goes up pin2 obtains a voltage that's about 0.6V below that at pin3.
This maintains the opamp output pin6 high through the first ramping functions, and only providing the current ramp would not drop.
The occasion the current consumption goes above the optimal range, the voltage across Rx commences to decrease, which can be magnified at pin3 of the opamp.
In spite of this pin2 at this point is not able to react to the above change because of the charge stored inside the 33uF which latches the "current-knee" parallel level at pin2.
Right now as the current falls even more, after an improvement of 0.6V pin3 potential begins obtaining less than pin2 of the opamp.
The above condition instantly reverts the opamp pin6 into a low logic.
The low logic at pin6 now does two executions at the same time.
It grounds the base of the BC547 transistor, forcing the ramp voltage to commence afresh from zero so that the complete process is renewed to the start stopping the solar voltage from reducing.
This also ensures that the 33uF cap releases for the subsequent ramp cycle.

The cycle hence sustains switching and restoring the circumstance making certain the technique would not obtain current above the rated point. Therefore holds the voltage of the solar panel at its highest stipulated open circuit level.
With each other, the I/V knee is rarely permitted to distort toward the inefficiency zone of the panel.

The talked about circuit is just at its presumed level and might need a lot of refinements until it truly turns into a almost achievable design. It's not yet examined by me.