List of DIY Electronics Engineering Projects

Portable Battery Charger Using Renewable Energy Sources like Solar or Wind Project

Every innovations starts from a simple day to day life problem like you watching IPL in TV and suddenly the current shuts off, fortunately you will find another way to watch the match via mobile network. Similarly, I too had faced a problem of frequent drains in mobile battery while travelling
somewhere in bus or while walking on the endless roads to our destination during hot sunny day.

There are many innovative projects on wind powered mobile charger which looks huge enough to produce 5v dc but they weighs more and bulky. I gathered some information from them for my project and started with a basic 12 volt DC motor. I used it to generate power for my mobile phones,and it ended up with failure.Then I used an feedback amplifier circuit but it was so huge.

Then got an idea!!!

A Multi-source Pocket Energy Generator(MPEG) OR Battery Charger Using Renewable Energy Resource.

A Multi-source Pocket Energy Generator(MPEG) is a portable and constant power source that can be utilized anywhere around the world. The world is in demand of proper utilization of renewable sources owing to frequent power failure. The MPEG is the best choice of interest for the utilization of alternate energies, facilitated with high portability.

Now my aim is to construct a portable power source that depends on renewable energies with efficient utilization of available resources. The MPEG receives energy from renewable resources like wind or solar energy and convert it into an electrical energy with output 5volt DC. In the absence of any of the above renewable sources, the 5V MPEG can be used with a single 1.5 volt battery to produce 5V DC output.
The problem of bulkiness, armature reaction in mini-wind generator and irregular availability of renewable sources are recovered by using our methodologies.


MPEG consists of a power generator, an amplifier circuit and an output port. The power generator may be a wind sourcing DC generator(range may be 1 v to 3 v) or a solar cell of dimension(4cm x 2cm) owing to portability or compatibility. The amplifier circuit amplifies the produces current to 5V DC. The IC used in this amplifier circuit is Max 756.

About The IC MAX 756:

The MAX756/MAX757 are CMOS step-up DC-DC switching IC for small, low input voltage or battery-powered systems. The MAX756 accepts a positive input voltage down to 0.7V and converts it to a higher pin-selectable output voltage of 3.3V or 5V.
The MAX757 is an adjustable version that accepts an input voltage down to 0.7V and generates a higher adjustable output voltage in the range from 2.7V to 5.5V. Typical full-load efficiencies for the MAX756/MAX757 are greater than 87%.

The problem of bulkiness, armature reaction in mini-wind generator and irregular availability of renewable sources are recovered by using following implementations.

  • The voltage fluctuation due to the irregular availability of sources can be compensated by using Zener diode regulator(Zener diode used here must be 5.1 volt- 1N4733A) .
  • The bulkiness are reduces by choosing small DC generator/solar cell of moderate power rating and then amplifying it to 5V and also by cyclically reducing the bandwidth of the ripples by using JK-flip flop clocked by T-flip flop as a counter.
  • The armature reaction due to the flow of current can be minimized by using brushless generator with halls sensors.Due to this arrangement ,self induced emf is removed using halls effect.
  • The efficiency of solar panel can be increased by using concave lenses and byallowing only a high frequency radiation from sun rays to excite all the electrons equally to high level.It can be done by using prism diffraction.Owing to problems in prism installation,we can implement them by using violet transparent sheet.

By using the above methodologies, we have constructed a portable power source utilizing renewable energies. The output of this MPEG is highly dependent on wind power, light intensity and battery power. By our field examinations, the following result were observed,

In wind generator mode:

At 35Kmph speed ,It produces 4.7volt and it reaches to stable 5volt at 45kmph.

In solar mode:

It produces a stable 5volt in the complete exposure of sun light.

In battery mode:

A 1.5 volt 1500mAH battery can be used to supply 5Volt for 1 hour.

The MPEG we have created can be availed by people at all places to charge their mobile phones, cameras, torch lights, headsets, to power microcontrollers, run servos, etc. This can be carried to anywhere and used at anytime during trekking, travel journey ,forestry visit, and also during emergency period wherever you are in need of a power source. By making some changes in switch, the can be able to supply light energy / battery power to the mini-fan or you can convert a wind energy (at night time) to light obtained by powerful green LED. Thus it is not only a solar powered mobile charger,wind powered mobile charger, it can also be used as a multi purpose pocket generator.The PCB implementation of his model greatly reduces the size to fit in your pocket.

Cerifications: This project has got first position in project presentation conducted by
EEE association ,Madras Institute of Technology,Anna University Campus,Chennai.

This post was written by:

S.Pragadeesan, Now doing his BE-Electrical & Electronics Engineering at A.C.Govt.College of Engineering and Tech,Karaikudi.

Contact Me @ Pragadeesan Homepage


Author & Editor

I'm Tittu Thomas, An Electronics and Communication Engineer from India, Kerala. I love doing hobby electronics circuits, blogging, programming, etc. Started this blog while doing my B-Tech degree under CUSAT university.

4 comments so far:

  1. Hi S.Pragadeesan...
    it is good and an impressive work however i can't find MAX756/MAX757 IC.can you suggest me an alternative IC to use please????????????

  2. i cant find max 756/757 any where
    can u suggest me an another one plsss..........

  3. Please sir, i made inverter of 100w sir and i realy love it but pls can i be using it with a solar panel of 5w 12v without using battery for it backup? I want to be using it for charging phones and lamp at day time (8am to 6pm). Please sir i will be very happy to hear from u sir! Thank you sir

  4. Can i get the maximum and minimum outputs of the components used in this "Portable battery charger " project.....asap
    its really very urgent


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