Simple DC Cellphone Charger Circuit

It is estimated that there are probably more cell phones in India than the number of toilets present here. Astonishing, but true. A simple DC cell phone charger circuit is one of those mates of cell phone that cannot be ignored because a cell phone would be dead without a charger.

Normally a DC cell phone charger circuit come as an integral part of a cell phone package and we use it in conjunction with our AC mains supply.

But what happens if your cell phone gasps for power in the middle of a journey, probably when you are driving or biking away on a middle of a highway?

A very simple yet reasonably effective DC to DC cell phone charger circuit is discussed in this article, which can be easily built at home even by a layman.

Though the proposed charger circuit won’t charge your cell phone at the rate equal to a normal AC to DC charger, nevertheless it will complete the function without fail and won’t betray you for sure.

The proposed DC cellphone charger circuit can be understood with the following points:

We all know the general specs of a cell phone battery, it’s around 3.7 volts and 800 mAH.

It means the cell phone would require at around 4.5 volts for initiating the charging process.

However a Li-Ion battery which is employed inside cell phones are pretty sensitive to bad voltages and may just blow off causing serious life and property issues.

Keeping this in mind the cell phone internal circuitry is specifically dimensioned very strictly.

The parameters just won’t permit any voltage which may be even slightly out of the range of the battery specifications.

The use of the versatile IC 7805 in the circuit answers the above issue just perfectly, such that the charging voltage at its output becomes ideally suitable for charging the cell phone battery.

A high wattage resistor connected at the output of the IC makes sure that the current to the cell phone stays well within the specified range, though this might have not been a problem anyway, the cell phone would just refuse to charge if the resistor was not included.

Simple DC Cellphone Charger Circuit

Pictorial Diagram

You can use this DC cellphone charger circuit for charging you cell phone during emergencies when there’s no mains AC outlets, the circuit may be powered from any 12 volt lead acid battery or similar DC power source

Parts List

R1 = 5 Ohm, 2 Watt,
C1, C2 = 10uF/ 25V,
D1 = 1N4007,
IC1 = 7805, mounted on a heatsink,
Battery, any 12 volt automobile battery

342 Replies to “Simple DC Cellphone Charger Circuit”

  1. Rajagilse

    Dear sir. Please tell me
    that what alterations
    should i do, to charge two
    mobiles at a time from
    this circuit.
    Could i give the parallel connection with the existing mobile charging pin. As ic 7805 is capable of giving 1A out put. Please guide me

    Reply
  2. Rajagilse

    Dear sir, i read the article in your link. But the writer says about current more than 2A . In my case if i put two mobiles to charge, it may be less than 1A. Therefore i think , what happens if i put another 5 ohm resistor and 10uf capacitor in parallel to the existing output of ic 7805

    Reply
    1. Swagatam Post author

      Hi Raja,

      2Amp is the max current rating, that doesn't mean that the cell phone will draw the whole current, it will use only the required amount.

      You will need to increase the wattage of the resistor, not the value, one capacitor is enough at the output.

      Reply
    2. Anonymous

      Dear Sir, I have a 2.5w Solar Battery Charger and its charging current is 180mA, power 2.5w max. Do I need a converter to charge my phone with it, or can I use it on my phone? Sir please guid me with what to do.

      Reply
  3. Anonymous

    Dear sir , an electrician told me that "In about 80% of the cases the reason for decreased battery performance is a sulphate buildup on the plates . And pulse or equalization charging can stop Sulphation . What does its mean ?do you have any circuit about it ? and please also give me an idea that what will the effect of "daily use and charge process " on inverter battery .
    Thanks
    Pankaj Pandey

    Reply
    1. Swagatam Post author

      Hi Pankaj,

      That's quite true, use of PWM controlled battery charging is recommended for tackling this problem with lead acid batteries.

      I will surely publish one article soon, discussing this issue elaborately.

      Thanks

      Reply
  4. Pradeep Raj

    Dear sir, Can I give the Input of 12v 50 amps to it. Its an inverter battery.. Will the circuit work fine or it burns out… Also tell me What is the maximum current and voltage that 7805 can hold..
    ~~~~~~THANK YOU SIR~~~~~~~~~

    Reply
    1. Anonymous

      Mr. Swagatam-

      If the voltage was less than 5V, for example a small, single cell, hobby grade LiFePo4 battery, which puts out less than 4V… could I just hook the battery directly to the cell phone as a small "emergency" charger?

      Thanks for any information and have a great week.

      Sincerely,
      Jim Kennedy

      Reply
    2. Swagatam Post author

      If it's 4V then it would charge your cell phone when hooked directly, anything less than 4V would make the charging inefficient and sluggish.

      You are welcome!

      Reply
  5. ashish

    dose the capacitors terminals matter here??
    if it matters can u tell me which terminal is to be connected to the ic

    Reply
    1. Swagatam Post author

      capacitors that are marked with (+) or (-) sign for their leads are polarized and ones that are without this are non-polarized….for example all ceramic capacitors are non-polar while all electrolytic caps are polar, unless specified

      Reply
    1. Anonymous

      is there no difference on output either to uses 12v or 6v 4.5AH bettery?
      what changes are required to use 6v 4.5AH bettery
      waiting for ur reply

      Reply
    1. Anonymous

      Ravinder Kumar Here
      Dear sir can you please tell me the circuit component value for 6 VOLT ,i have planned to prepare mobile charging circuit run with 6 volt lead acid battery ….

      R1 = ?
      C1, C2 = ?
      D1 = ?
      IC1 = ?
      Battery = 6volt lead acid .
      waiting for your reply..

      Reply
    2. Ravinder Kumar

      Ravinder Kumar from Indigenous Home made Tech is here -Dear sir i used u r given circuit (with C1,C2= 10uF/25V )BUT by using diode and resistance does not work ,so i have removed diode and resistance now its charge but not 100% it charges the cell phone only to 70% by using 6volt 4.5Ah Battery ,
      Request you please suggest to increase charging efficiency limit to 100% .

      Reply
  6. Anonymous

    can i connect the output terminals to a socket and then connect it to a battery charger??

    and is there any other way by which i can test the circuit before connecting it to cell phone chager??

    sir sir is there any specification for the wire that is to be used to connect the 6v battery to my circuit??

    Reply
    1. Swagatam

      This circuit has been tested by me, and it works.

      Just connect the output of the circuit to a suitable pin so that you can insert the pin into the cellphone charging input.

      You can use any type of wire, as long as it conducts electricity it'll be fine.

      Reply
    1. Anonymous

      no sir
      i was saying about the output current .it iwas 4.3 amp

      my output voltage is around 3.2 volts
      by using a 6 volt battery

      Reply
    2. Swagatam

      No there's something wrong with your circuit, the output voltage should be 5V even with 6V input.

      The current is not important here as long it is able to provide above 500mA, the cell phone will get charged.

      Reply
  7. Anonymous

    why can we continue to connect about x6 of the same lithium ion cell(i mean the collapsed one) in parrallel and in series to get a good output then your circuit sir

    Reply
  8. cedar

    Swagatam,
    All your circuits are simple and clear, it's great!

    Your circuit uses R1 = 5 Ohm, 2 Watt, and C1, C2 = 10uF/ 25V, does it need to be exactly 5 Ohm, 2 Watt, and 10uF/ 25V or we can also use other values suppose if it is not available ?

    Reply
    1. Swagatam

      Hi Cedar,

      Nothing is critical here except the IC number.

      You can use any value for the resistor from 5 to 20 Ohms, however increasing the value will slow-up the charging process.

      You can use any value above 1uF for the caps too….

      Reply
  9. kataga salita

    tnx sir it works fine,,sir can i know what is the difference in using all parts that u give and using only 78m05 and a 5 ohm resistor (2 parts),, again sir thank you so much,, you re our macgyver of today,,

    Reply
    1. kataga salita

      thank you so much for the info.. god bless you always,,,
      sir can i ask you again,, how to adjust ( increase ) ampere of a battery? iam 24 y/old i have a son 4y/o i gave him a battery operated toy car,, 6volts 4.5 ampere.. he can only play it for only 1 hour,, can i adjust its ampere so he can play it longer?.hope that im not bothering you…thank you so much…

      Reply
    2. Swagatam

      Hi Kataga,

      If you reduce the ampere of the battery the car will not work properly, you can add one more 6V/4ah battery in parallel to the existing one for increasing its operating time.

      Reply
    1. Swagatam Post author

      Normally the pin which is shown in the diagram has its outer metal connected to the negative and inner metal to the positive of the voltage source.

      Reply
  10. Anonymous

    Thnxx
    I know that but in android chargers its a bit different its a flat pin charger and i tried checking with a multimeter
    Thnx in advance

    Reply
    1. Swagatam Post author

      You will need to find out the positive and the negative outputs of the socket and connect them to the above charger appropriately, you may take the help of a phone technician.

      Reply
  11. Anonymous

    hi sir. Can i connect 12volt solar cell? If yes what should be the current rating of the solar cell . My battery is 3.7 volt @1020mah

    Reply
    1. Swagatam Post author

      You cannot connect the Li-Ion cell directly to this circuit, the above circuit is for charging cell phones, not the battery directly.

      You may connect a 15V, solar panel at the input, current can be anything that's above 1amp.

      Charge the battery by putting it inside a cell phone.

      Reply
  12. Anonymous

    Hi

    Just want to know whether the AC-3N Nokia Charger with 5V 350mA can be used on a device that requires AC 6V 300mA ?

    Thanks in Advance.

    Regards

    Reply
  13. abbas shaikh

    hi. sir.. ye ckt mere meri herohonda HUNK bike me lagani hai.. to kya lagegi.? isse mere nokia 5230, apple 4s charge hoga.?? agar bike running hai to koi problem to nahi hogina..?? ya bike off kar k cells charge karne padenge.??? plz.. help me.. ans me..

    Reply
    1. Swagatam Post author

      Hi Abbas,

      you can connect its input to the battery, you can charge your phones even while riding.

      I am not sure whether it would charge all your phone, you will have to check it out.

      Reply
  14. Anonymous

    Greetings!!

    Sir it is safe if i put the unit somewhere safe under the saddle and permanently attach inputs to the battery?.

    How about inline fuse, it is safe without it Sir? Thank you!

    Reply
    1. Swagatam Post author

      Greetings!

      According to me it's a very safe circuit, a fuse is not required. Permanent connection to battery is OK. A heatsink is essential for the 7808 IC

      Reply
    2. Anonymous

      Thank you very much Sir, some other query… what size of heatsink it should be? can you explain it by inches Sir, what i've got is just 1inch square with a half inch thick from the rib.

      Another thing Sir, your diagram says 1uf/25v cap while partlist is 10uf/25v cap. what is the difference using either value Sir. Thanks

      Jane

      Reply
  15. Anonymous

    Hi Sir,
    I want my motorcycle to have two set of horn tone, one lower or just the stock horn tone and the other is louder or even loudest if possible, without sacrificing the battery charge.

    Do you have a circuit for this Sir? or any other suggestion to obtain a more louder horn but maintaining the stock horn, maybe using a toggle switch for the purpose of having a dual horn tone.

    Thank you very much Sir, I hope i could do it with your assistance Sir.

    Regards,
    Jane

    Reply
    1. Swagatam Post author

      you can use the above circuit, but you will have to monitor the charge manually, the moment it reaches 3.7V you will need to switch off the charger.

      Reply
  16. Anonymous

    Hi Sir
    I am trying to charge my cellphone (Nokia) with lead acid 4.5 volts small battery ( which comes fitted in the emergency LED lights). For this purpose I connected the said battery directly to the phone but it did not respond. I you have any circuit diagram for this purpose, please send on the following address. My phone need 4.9 volts to 5.3 volts and 500 MA for charging.
    Thanks,
    My address: adnan_nagra@yahoo.com

    Reply
    1. Swagatam Post author

      Hi Adnan,

      if your cell phone uses a 3.7V li-ion cell it should accept charge from a 4.5V battery.

      try putting a 5 Ohm 1 watt resistor in series with the battery positive,it might start charging.

      Reply
    1. Swagatam Post author

      Hi Sanket, no it's not possible because the source voltage must be at least 0.6 volts higher than the battery voltage which is being charged, here both will have identical levels, so not feasible.

      Reply
  17. Anonymous

    Sir, I have 9 volt dc battery.. i wants to make a DC to DC charger for this 9 volt battery.. i wants to make a charger in such a way that it will get charge while in use.. like batteries in Mobile phone so on.. Please tell me how to make one

    Reply
    1. Anonymous

      hi sir,, actually i am visualizer.. i do not have any knowledge about electronics or electricity.. I just see things, read things, tries to understand and creates the possibilities not practically but in my thoughts.. so please help me..

      Can we make a charger(Circuit) for any rechargeable DC battery… which can charge himself??? like take 9volt dc rechargeable battery..

      Please do let me know on atulkamble99@gmail.com

      Reply
    2. Anonymous

      Sir,

      i am trying to visualize something plz help me to get it possible.
      i will ask you some questions.. plz try to figure it out whether it is possible or not

      (if have 1.2 volt with 2400mA dc battery)
      upto what voltage you can amplify? current should be minimum 500mA.

      sir there will be a lot more questions i will be asking you… plz try to contact through mails. atulkamble99@gmail.com.. this will be lot more easy..

      Reply
  18. Anonymous

    dear sir,
    can i use alkaline battery of 1.5V instead of lead battery.(pencil cell)
    and using total 4 cells will make it to 6V.
    and if it is so then please inform me is there any other change in circuit due to it

    Reply
  19. Mrs.Yaman

    please, i sent you before if i can use only resistor to make simpler version of this charger.
    i'm supervising a group of kids in science clup and they want to make mobile charger.. and i want to be as simple as possible
    waiting for your respond

    Reply
    1. Swagatam Post author

      you may use a resistor only when the source voltage is 5V or less, if it's more than 5V then first it will need to be dropped to 5V and only then a resistor may be used as shown in the above article.

      Reply
  20. Seetha

    hi swagatam sir,
    i work with this circuit but it slowly charging i want improve the chargering levels (means fast charging) tel suggetions sir and hw can i measure current flowing through this ckt sir. i think small currents are flowing. and how can i improve the current in this circuit sir.
    plz rly me sir.

    Reply
    1. Swagatam Post author

      Hi Seetha,

      The current can be increased by appropriately decreasing the value of the output resistor. try smaller resistor values for charging the cell phone faster.

      Reply
  21. Seetha

    using above circuit only some phones charged my ph nt chh arging ph specifications r 3.7v 880ma bt above circuit gives 890ma if load will connect to the circuit current drops na sir

    Reply
  22. Seetha

    i changed 5 ohm resistor and place 1 ohm and checked bt charging levels are nt inceased. nokia phones r charging properly sir i maen those specifications r 350ma. from the circuit i am connect one usb for samsung and apple phones and also connect nokia charger teminals for charging bt samsung phones charging slowly sir those phs require 880ma. how can i solve this problem rly me.

    Reply
    1. ABDUL BASIT

      sir in the first diagram,in which there is input of 12 dc battery,will there also need diode ??
      or if i want charge from automobile then i se diode??
      thankss

      Reply
    2. Swagatam Post author

      diode is placed only for safeguarding the circuit from accidental reverse input connection. You can remove it but be sure you connect the input polarity correctly then.

      Reply
  23. ABDUL BASIT

    thanks sir
    sir can you tell me how much time required for charging a mobile???
    & sir i have project about bicycle dynamo. sir if you don't mind can you send me an easy diagram to make bicycle dynamo/bicycle generator??

    Reply
    1. Swagatam Post author

      2 to 3 hours will be required.

      you can connect the dynamo output to the above circuit via a bridge rectifier stage and start charging the cell phone as explained above.

      Reply
  24. ABDUL BASIT

    sir can i connect this circuit with motorbike battery and car battery??
    if yes ,so will there any problem of input & outout current because automobile battery's current is very high??
    i know voltage is not a problem.. what about current.
    THANKS FOR YOUR ALL PREVIOUS HELP SIR…..

    Reply
  25. ABDUL BASIT

    sir please tell me if you have any knowledge about any softwere about circuit designing in which bicycle dynamo ,d.c motor or other mechanical equipments present????

    Reply
  26. Anonymous

    assalam o alaikum i am omar respected sir i want charge my cellphone and also a battery that is connected to this circuit… also my cellphone battery have 1300 ma current requirment. . . suggest me the possible design. . .
    thanks

    Reply
    1. Siva Murugan

      sir,this condition ok…the 12v continuously going at 7805 and step down to 3v…normally example you take mobile charger,u have charging mobile, charging and the battery is full….and automatically disconnect the charger….

      in this project,only charging the battery not getting the charge is full condition automatically disconnect condition..how to get automatically disconnect after the batter full..plz give me the circuit and information………

      Reply
    2. Swagatam Post author

      mobile chargers do not have auto shut off feature, rather cell phones have auto cut off feature in-built, therefore it's safe because the cell phone in-built circuit would cut off as soon as its battery gets fully charged.

      Reply
  27. ABDUL BASIT

    HELLO SIR..
    SIR MJHE UNI PROJECT K LIA AK CIRCUIT CHAHEA JISME 2 IC lm714 US HO..SIR PLEASE KOE HOMEMADE PJOJECT KA LINK SEND KR DIJEA..
    I WILL BE THANKFUL TO YOUU…………….

    Reply
    1. ABDUL BASIT

      thanks sir.
      but I m student of 3rd semester. this schemetic is little bit complex
      for me.so sir please send me an easy schematic. so I can make it .
      thank u sir for helping me a lot… …

      Reply
    2. ABDUL BASIT

      HELLO SIR……..
      SIR APNE JO SEND KIA THA LINK ME WOHE BNA RHA HUU..
      MENE APKE BLOGES ME RELAY CONNECTION PARHA . KCH SMJH AYA SIRF YH BTA DE AP K JO RELAY KI 5 PINS HA WO KHA KHA CONNECT HA???
      N/C & N/O KHA CONNECTED HA:COIL TERMNALS KHA CONNECTED HA??
      AUR JO PICTURE ME 12 VOLT K UPAR BLUE LINE HA WO KHA CONNECT HORAE HA.
      SIR I HAVE ONLY 3 DAYS TO MAKE IT .
      THANKSS…..

      Reply
    3. Swagatam Post author

      The square box named 'relay" is the coil of the relay, among the contacts the upper circle is the N/C and the lower circle is the N/O, the central link is the moving pole of the relay.

      Reply
    4. ABDUL BASIT

      THANKS SIR.. YOU CLEARED MY CONCEPTS.
      BS MJHE YH BTADE N N/O, N/C & MOVING POLE OF THE RELEY CIRCUIT ME KHA CONNECTED HAIN????AK TO YH RELAY ME CONNECTED HA LEKIN YH CIRCUIT ME KHA CONNECTED HA YH NAE PTA CHAL RAHA..

      Reply
    5. Swagatam Post author

      N/O, N/C and the pole are not connected to the circuit, they are connected to the load or an alarm via AC mains, there's no connection with the circuit.

      If you are using a DC alarm then you may connect it with the circuit 12v supply.

      Reply
    6. ABDUL BASIT

      ok sirr
      sir jo 12 volt dc alarm ha iska koe link send krde. mjhe zehan me idea nae arha..
      project bhht acha lga ha mjhe iSlia yhe bnana cha hu.complex ha but i will try my level best.
      aur relay ki 3 wire jo alarm se connect HA uska be lnk btade
      THANKS SIR…….

      Reply
    7. Swagatam Post author

      don't make the aarm, buy it from the market, you can use a car musical horn or a 12v musical door bell.

      relay connection:

      pole to 12V(+), N/O to alarm (+) wire and (-) of alarm to circuit ground or supply negative.

      Reply
    8. ABDUL BASIT

      THANKS SIR..
      sir yh jo diagram me A1 HA ISKI Pin 1 to led k sth aur pin aur pin 2 potentiometer k sth ha but confusing pont is k pin 1 & pin 2 k bech me se ak point upar 12 volt aur resister k sth node bna rha ha. yh ks pin se nkal k upar ja rha ha.aur sirf A1 KI 3 PIN CONNECTED ha bki kia ground krni ha???
      and same question for A2 .usme be pin 5 & 7 connected ha aur bech mese ak wire jake grounded ha.yh knsi wire ha???

      Reply
    9. ABDUL BASIT

      SIR IS THERE ANY WAY TO CONNECT WITH YOU & YOUR KNOWLEDGE DIRECTLY????
      BECAUSE SOMETIMES I WANT QUICK ANSWERS AND FROM BLOGS, I HAVE TO WAIT 1 DAY. KINDLY TELL ME ANOTHER WAY SO THAT I CONNECT WITH YOU DIRECTLY ..
      THAKNS SIR..

      Reply
    10. ABDUL BASIT

      Sir please tell me connection of relay with dc alarm . I am using dc alarm for output.
      Secondly, if I want to check the circuit that it is working or not without an alarm, how I check it???
      Actually mjhe teacher ko check krwana ha without alarm.

      Reply
    11. Swagatam Post author

      relay connection:

      pole to 12V(+), N/O to alarm (+) wire and (-) of alarm to circuit ground or supply negative.

      The red leds will be shut off after setting up, and when a motion is detected across any of the LDRs the relevant red LED will light up indicating a motion.

      Reply
    12. ABDUL BASIT

      This means sir that N/0 does not use in this circuit.??
      And pole se phir 12 volt p connect krna ha?? I can't understand. Please send any diagram from which I understand.
      THANKS….

      Reply
    13. Swagatam Post author

      pls read the connections again, N/O is connected to (+) of alarm circuit, N/C is blank, not connected anywhere.

      (-) of alarm circuit is connected to supply negative

      relay pole is connected to supply positive

      Reply
    14. ABDUL BASIT

      I UNDERSTAN SIR..
      SIR IN MY CIRCUIT,ONLY ONE LDR IS WORKING ,WHEN I DISCONNECT ONE LDR,OTHER LDR WORK AND OTHER PROBLEN IS THAT IT WORKS IN OPPOSITE FORM MEANS WHEN IT DETECTS ANY MOTION,LED OFF OTHERWISW IT ON ALL THE TIME.
      AND SIR TELL ME HOW I SET P1 & P2???
      THANKSS….

      Reply
    15. Swagatam Post author

      you may have connected the pinouts wrongly, i have tested this circuit it works superbly.
      when correctly set both LEDs will switch off completely and illuminate only when a shadow is detected across any of the LDRs.
      I have explained the set up procedures in the article.

      Reply
    16. ABDUL BASIT

      sir kindly tell me the connection of potentiometer?? like it's first leg is connected to 10k resister ,i m confused about second & third pin connection.tell me the connections for both , P1 AND P2.
      THANKS FOR HELPING ME ALOT..

      Reply
    17. Swagatam Post author

      use the center pin and any one of the other pins, that's all…
      center pin is compulsory, the other one can be any of the remaining two.

      I have made some changes in the diagram, please do it in your circuit also, it will give better results, and pls comment on motion sensor article, not on this page.

      Reply
  28. Anonymous

    Hi Swagatam,
    I came here just to say Thanks. I've been following your blog for some time and I quite like it. People ask all sorts of questions, some silly though, but you responded nicely every time. Keep it up. I'll keep reading every publication of yours and may be I too will seek help sometime… Pukhrambam

    Reply
  29. faizan khan

    hello sir
    sir mujhy 12v bike ki battery sy mujhy 15v out chahey or internet device chalane hai
    or woh bhe atomatic yane k lite jae to auto battery per ajae plz plz plz plz plz sir help me…………plz plzp plz.

    Reply
  30. Alealu

    Heloo Dear sir
    I like your response and advise and bless you!!
    My question is is it good to use 5v,1w solar panel for the above circuit application with out 7805??What about 6v ,1w solar panel with 7805????

    Reply
    1. Swagatam Post author

      Hello Alealu

      Thanks!

      with a 5V solar panel you don't have to use any IC at the output, you can connect your cell phone directly with the panel via a 5 OHM/ 1 watt resistor….it will start charging.

      Reply
    1. Swagatam Post author

      when you say it's a 5V panel it signifies the peak value at peak sunshine, so technically it cannot exceed this level.

      But anyway you can use the above circuit in conjunction with it for better safety.

      Reply
    2. Alealu

      I mean, even if it is 5v peak this voltage do not exceed 5v but may goth below 5V ,so the voltage may be 5,4,3,2…..v depending up on sunshine,As a resale,is such low voltage is safe for mobile battery life????

      Thank you

      Reply
    1. Swagatam Post author

      You can use a 7809 IC at the output, it will give you a 9V/1amp output from your 12V battery.

      The connections will be same as in the above 7805 design

      Reply
    2. Swagatam Post author

      Hi Jhud, you can do it, but use two 7805 ICs in parallel for getting a better current gain and quicker charging rate. Make sure that both the ICs are mounted on a common heatsink. also reduce R1 to 3 ohms/5 watts

      Reply
  31. charles Odtohan

    good day sir… i did loved your blog.. bcoz its very usefull here in our place this time becauze we have no electricity… so i did make your circuit but i got an error in my cellphone.., bad contact of charger… i did use 2 10uf, and 5ohms 2 watt.. pls help.. thnx..

    Reply
    1. charles Odtohan

      tnx sir… i'll try as soon as i can buy 10 ohms or higher…
      —–
      sir, i have here a 9v dc solar panel.. i only get around 5.5v-8v dc (not stable) if its not so sunny… can i still use this circuit?

      Reply
  32. ABDUL BASIT

    Hello sir.
    Sir I want some help from your side. Sir I have project regarding computers logic design. Topic is:
    DESIGN AND IMPLEMENT A CIRCUIT THAT COULD GLOW A LED WHEN 3 OF THE AVAILABLE 7 TANKS NEED A REFILL.
    Sir I want circuits or if u have idea, so tell me.
    THANKS SIR………

    Reply
    1. Swagatam Post author

      Hello Abdul,

      You will have to provide me with full details regarding the application need, only then I would be able to come up with something suitable

      Reply
  33. ABDUL BASIT

    sir using different gates,i have to make circuit . there are 7 tanks available,when 3 0f them are empty so led which is connected at output is glow. A combination of gates is using here.what logic is using sir??

    Reply
  34. marque torres

    Hi Sir..

    Your blog gives a lot of knowledge about charger circuit… thanks for this ideas as will as the circuit you shared to us… i would like to make a 48 v 1+ amp supply, can i use the above circuit with IC??? or what should be the value of R=?,C=? and the IC number=? … thanks a lot Sir…. God Blesses you always…

    Reply
  35. jacob arul

    Sir normally mobile phone charger have lot of components so mobile battery life is well.but in this circuit have simple few components how to trust this and what about mobile battery life after charged this circuit?plz ans me sir.

    Reply
    1. Swagatam Post author

      Jacob, the above circuit also has many many components all hidden or embedded inside the 7805 IC, so it's also sophisticated and absolutely safe, moreover your cell phone has a built-in overcharge cut-off protection so there's no danger of the battery getting over charged.

      Reply
  36. Yoshin

    Hi sir. Im thinking about using piezoelectric sensor to be used as the input supply for the mobile charger. Do you think it is possible?

    Reply
    1. Swagatam Post author

      Hi Yoshin,

      you would require a 1000 piezos in series/parallel and a lot of sound pressure to create a valid charging voltage for the cell phone.

      Reply
  37. Yoshin

    Oh i see..sir i also would like to ask you about hardware implementation for speed control of DC drive by mobile phone. The mobile key in the amount of duty cycle and send the signal to the chopper, connected to the dc motor. Speed changes by duty cycle. Do you have any idea on how to make the circuit since no software is needed. I mean how we key in the amount of duty cycle in the mobile phone? Thanks..

    Reply
  38. Utkarsha 1992

    Hello sir, i am utkarsh . Sir, i am try to make cell phone charger by lm 7805 resiser diode and the capacitor . All the components are same as you mention except capacitor(it is 63v 1micro f) .
    But sir i have a proble my phone shows charging but it take more than 10 hours to charge and then i replace all componet then charge it by only ic but i did not get any gain. I also try to vary resistor value but no effect . Please help me soon to make charging fast and also the above circuit could not able to charge nokia 1600 and 2626 … Thank you sir… Please reply soon at my mail (rudresht2@gmail.com) thankyou…

    Reply
  39. siddu

    Hi sir,

    Above mobile charging ckt is working fine but charging time taking more with battery 12V/7Ah I mean its not charging normally using charger as my Samsung Mobile charger specs out put is 12V/0.7A so kindly suggest me how to reduce long charging time.
    From Siddhalingesh

    Reply
    1. Swagatam Post author

      Hi Siddu,

      the above circuit will not charge your phone quickly, if we try to increase current the phone may refuse to take the charge…..however you can try decreasing the 5ohm resistor to 3 ohm or 2 ohm and check the difference.

      Reply
    1. Swagatam Post author

      dear Dev, such big value caps are not required for the above 7805 circuit, you can use smaller caps, I am not sure about ctc13651 circuit because i have not seen it

      Reply
  40. Dev Aarya

    Hello Sir,
    I made that charger and its working but theres slow charging rate for Samsung mobiles, it takes many hours. can i fix it by modifying the circuit? and i want to put an LED indicator light in that circuit, where do i fix it?
    THANX!

    Reply
    1. Swagatam Post author

      Hello Dev, try reducing the 5 ohm resistor to 2 ohm and check the response….for getting an LED indication connect a LED with a series 1 k resistor across the 2 ohm or the 5 ohm resistor

      Reply
  41. Muhammad Fahad

    Hi sir
    i made this circuit. but when i am connecting diode IT DOESN'T WORK. BUT WHEN I DISCONNECT DIODE IT'S WORK. KINDLY SIR PLEASE TELL ME IS THERE ANY PROBLEM IF I NOT CONNECT DIODE IN THIS CIRCUIT?

    Reply
    1. Muhammad Fahad

      Hi Swagatam!
      I did it but i am facing one more problem. it is outputting 4.5v dc i need 5vdc proper voltage for charging my android phone. and run my usb portable speaker i removed resistor . but it's not working. by this circuit my phone is charging just 4% in hour. it is too slow,

      Reply
  42. Vivekanand Prasad

    helllo sir, i am using a 18650 battery hat i have extracted from my laptop cell. NOw please provide me a circuit that can provide an ouput of 5v 2amp, while im giving an input of 4.1 volts.

    Reply
  43. raymond gablines

    Good Day Sir,
    I follow the circuit that you given sir, but i use other value of components sir. D1= 1n4007, C1= 100uF/16v, R1= (Brown, Block, Brown, Gold= 10 x 1= 10 ohms [5%]), C2= 100uF/25v. Is it ok sir?

    Reply
  44. Ahamed Anaz

    Sir can u plz tell us how u chose the specs of parameters. And help us to know the purpose of each and every components used in the circuit plz. And finally Shall we use 50v capacitors instead of 25 V capacitors? Thank u.

    Reply
    1. Swagatam Post author

      Ahmad, since a cell phone normally requires around 4.5 to 5V as the charging input therefore I selected 7805 IC for regulating the input to 5V. The capacitors are just for filtering any residual noise in the DC and are not so crucial, the limiting resistor acts like a buffer so that the all types of cell phones become compatible to the output from the charger, and the current gets adjusted accordingly through the resistor.

      Reply
    2. Ahamed Anaz

      Thank u very much sir. I thought this post was outdated so u may not reply. Happy to see ur reply. And does the value of output current differs wen we use differently rated batteries. If it so then different current values don't affect th mobile phone battery?

      Reply
    3. Swagatam Post author

      You are welcome Ahamad,…..nothing is outdated in my site, everything's LIVE and updated regularly with my expertise.

      output current does not matter because the voltage is constant, so you can use any mobile with this circuit which uses 3.7V cell, it will start charging immediately….but bigger cellphones will take much longer time to get charged than smaller phones

      Reply
    1. Swagatam Post author

      Sudhee, yes all cell phones have an in-built highly accurate over charge cut off circuitry, so there's never a danger of an over charge to the connected cell phone even if it remains permanently connected with a switched ON charger……

      Reply
    1. Swagatam Post author

      Ajay, can you provide more details about the shoe charger, regarding its concept and voltage?

      if the output from it is above 5V in that case you can employ the above shown circuits.

      Reply
  45. Jhud Ador

    Hi.. sir I have Samsung Galaxy duos Gt I9082
    Battery 3.8V Li-ion
    2100mAh

    can i charge it in my motorcycle battery using the above Circuit?

    thanks in advanced.

    Reply
    1. Swagatam Post author

      Hi Jhud, you can do it, but use two 7805 ICs in parallel for getting a better current gain and quicker charging rate. Make sure that both the ICs are mounted on a common heatsink. also reduce R1 to 3 ohms/5 watts

      Reply
    2. Swagatam Post author

      …also add one 1N5408 diode in series with the output positive line, this will cut down the output to 4.3V approx…making it perfectly suitable for charging the 3.7V Li-ion cell.
      However please remember that the circuit does not include an over charge protector so make sure to monitor it manually and remove it as soon as it gets fully charged.

      Reply
    3. Swagatam Post author

      Hi Jhud, you can use it with a 1 ohm 2 watt resistor instead of the shown 5 ohm….but still the the charging time could be much prolonged with this IC.

      Reply
    1. Swagatam Post author

      Hi Ravin, with a 6V input, a 7805 can be avoided….just use two 1N5408 diodes in series with the positive…that will do the job.

      but if you prefer a 7805 you can try it as a 5V regulator.

      Reply
    2. Swagatam Post author

      after connecting the mobile should indicate "charging"…if this not happening that means your mobile is not accepting the input charge.

      Reply
  46. Ravin Kumar

    Hi sir this is Ravin Kumar.
    what we have discussed about 7805, I was used 7805 as a Voltage regulator for mobile battery charger using 6V battery.
    what is the problem I was facing is mobile in display showing charging symbol and connect sound ….!
    But its charging % indication looks like decreasing condition…
    I dont know what is the problem in that….!

    Reply
    1. Swagatam Post author

      Hi Ravin, when you connect the charging input to your mobile it should immediately acknowledge by showing the "charging" indication….the battery symbol should start showing a sequencing response….if this not happening then you can be sure that your mobile is not accepting the charge input.

      do not use the mobile while it's being charged,, otherwise the charging level will start decreasing.

      Reply
    1. Swagatam Post author

      Rehan, no that's not recommended because old batteries may have different voltage and health conditions so they cannot be put in parallel for implementing the power bank.

      Reply
  47. mohammad dani

    sir mene ye circuit 12v 7amp dry battery me connect kiya but it does not work,,
    just charging hoti rehti hy jese hi pin remove karo cell se to charging wohi ki wohi hoti hy:(
    will u help me?????

    Reply
  48. Unknown

    Hello sir,
    If we will used this ckt for long time then it will occur damage in the mobile battery and mobile components. Waiting for your answer sir ,thank you sir

    Reply
  49. Jignesh Parmar

    Hello sir,
    My question is if we will used this ckt for long periods then it will occur damage in the mobile battery and mobile components pls give me the answer , thank you sir

    Reply
    1. Swagatam Post author

      Hello Jignesh,

      No, there will not be any problem even if you connect the charger permanently with the cell phone because the cell phone internally has an over charge protector…which will instantly cut off the current as soon as the battery gets fully charged…however it's always a good practice to disconnect the charger through a visual monitoring….

      Reply
  50. Salman Ahmad

    Sir in the diagram you show C1 and C2=1uF But in parts list you write 10uF.which is right.You also write 5 ohm =1 watt but in parts list you write 2 watt pllzz guide me which is right..

    Reply
    1. Swagatam Post author

      Salman, C1, C2 values are not critical, you may use any capacitor in that place, the resistor could be 1 watt…. but 2 watt will provide even better cooling…so it's up to you to choose

      Reply
  51. kaushik wavhal

    Can this circuit charge a phone with a 3000mAH battery?
    My phone's charger outputs 5V , 2.1A . Though this will output max current till 1.5A and the charging will be a tad slower.

    Reply
    1. Swagatam Post author

      If you are having a 5V charger then I don't think the above circuit would be required…you can use the 5V charger directly to charge the cellphone.

      Reply
  52. siddu

    about cell phone charger

    Dear sir. Please tell me what alterations should i do, to charge two mobiles at a time from this circuit.Could i give the parallel connection with the existing mobile charging pin. As ic 7805 is capable of giving 1A out put. Please let me know

    Reply
  53. siddu

    hi swagatam,
    thanks for all ur valuable comments.
    as u said cell phone will accept 5V only but how its possible may if we gave >5Volts also accepting because i have seen practically example motorola cell phone battery buldge or bad condition if you use long period using with compatible charger ERD charger. if i use original charger branded one then battery become good condition this thing i have observed long time by comparing both things so can u clarify me why my cell battery become buldge or bad what are reason ?

    Reply
    1. Swagatam Post author

      Hi Siddu,

      all cell phones have internal overcharge protection and sophisticated voltage regulator circuitry, so what you are saying can NEVER happen unless you have used a duplicate battery inside the phone…..so the problem may be not in the charger but the battery used in the phone….or may be the cellphone itself could be a duplicate MOTOROLA, not an original motorola. 5V input is well handled by any cellphone, and if at all it anticipates a incompatibility the phone will simply stop charging.

      Reply
  54. SOBHAN MAJUMDAR

    sir . i have 4 1.2 v ,1800amh battery, i want to make a power bank.I make it,but it charge only my nokia,samsung(old verson phone).it can not charge my redmi2 phone. redmi2 input voltage is 5v 1A. how can i make it.please help mw to solve it out.

    Reply
  55. Umair Anwar

    Sir I have made this circuit.my out put voltage is 5.20.but my cell phone charges only 2% or 3%.then it stays connected(charging) but percentage of charging not increases…like it shows very very slow charging.what is the problem and how I can solve this

    Reply
  56. Umair Anwar

    Sir I have made this circuit…Output voltages are 5.45V..charging speed is so high,10% in just about 10 minutes…but when disconnected..same case that discharging was so high…then steady at the same where from I start charging…

    Reply
    1. Swagatam Post author

      Umair, you must keep it connected until the cell phone indicates "battery full", if you remove it in the middle then it could drop quickly.

      Reply
  57. Umair Anwar

    Ok..but sorry…this circuit just charge few percent(5-10%) very fast in first time connection..then stops and keep stops for many hours until I remove connection…no exceeding further…I check the voltages in USB port..these are good in between 475-520…but charging not increase.i have changed many input 12V batteries…what will be the problem…?

    Reply
  58. Umair Anwar

    I mean ….can I use 9v,3w solar panel as input in this circuit?..I m using this..but output voltages are exact 4.50volts and ampereges are 1.70A…my cell phone charges few percent only..then stops charging but connection keeps there(charging)…

    Reply
    1. Swagatam Post author

      without load the output from a 7805 should be around 4.9 to 5.1V with a 9V input….if it's showing 4.5V then the IC could be duplicate or bad in quality.

      and make sure the IC is not hot while charging the phone…use a large heatsink to avoid this

      Reply
  59. Arindam

    Hi
    Can I use 4pcs 1.2v 2000mah rechargeable batteries in series to charge the cell phone battery directly, if yes then how the rechargeable batteries to be charged

    Reply
  60. Muhammad Arslan

    Sir I want to make a mobile phone charger using transformer, bridge retifiers and capacitors as well as zener diode restriction is that there is no use of IC can u plz help me in finding the circuit and components I shall be very thanksful to you ..

    Reply
    1. Swagatam Post author

      Muhammad, you can do it by using 0-3V/500mA or a 0-4.5V/500mA transformer and rectifying its output with bridge/capacitor network. A zener diode will not be required for this, but make sure to add a current limiting resistor such as a 2ohm or 3 ohm 1 watt resistor.otherwise the cellphone might just refuse to accept the supply

      Reply
  61. Anonymous

    Sir,I need 5 v-500ma output. Can this circuit give DAT or I have to change d value of d resistor….pl.reply…

    Reply
  62. Govinda Raju Kolla

    Dear sir
    im using below circuit but im not using 5ohm R im using 4.7ohm resistance but my mobile was silly charging but not changing charging levels its constant please help me sir whats problem in my circuit

    Reply
  63. Bibin Joseph

    Hi sir..hi do tho circuit..sOme mobiles can charge..my Lumia 720 couldn't get charged..how I modify the circuit?.. It's battery spec. is BP-4GW 20mah 3.7v 7.4WH Lithium polymer max 4.2

    Reply
  64. sandeep sundaresan

    Hai sir,
    I made this circuit and my phone is charging, but its very slow and my phone battery is drawing around 250 mA.Is it working properly and what is the importance of 5ohm 1watt resistor. Also regulator ic is getting hot i am using a heat sink also i connected a cooler fan ( 12v) at the input pin of 7805. I am using an old 12v 7 AH battery. Plz guide me sir

    Reply
    1. Swagatam Post author

      Hi Sandeep,

      you can try reducing the 5 ohm to some lower value for increasing the current and improve the efficiency….this resistor acts like a buffer and limits the current to an acceptable level, otherwise the phone circuit might refuse to accept the charge….

      If you attach a large heatsink, then I don't think a fan cooling would be required.

      Reply
  65. Anonymous

    Dear Sir is it safe to charge a cell phone with this circuit, coz Li-on Batteries are very sensitive.
    I dont know much about electronics but found this one as interesting was trying to build one, before building wanted to enquire and also can we connect this to a car battery and charge the phone.
    looking forward to your reply.

    Reply
  66. lima toshi

    hi firstly one if the best learning electronics sites ever, thank you sir for sharing your knowledge with us appreciated. Sir i was wondering can i use lm7806 to make a power bank for charging a cell phone, because when i check a cell phone's charger with a multimeter the DC voltage is 6volts and not 5volts, i am new to electronics so i don't want to cook my cell phone, so any help will be greatly appreciated. Thank you.

    Reply
    1. Swagatam Post author

      Hi Lima, even with 10V your cell-phone will not fry because it has an internal voltage control protection.

      however 5V is the correct recommended voltage for charging a cell phone. the 6V which you are seeing is due to the absence of load, as soon as you connect the cell phone, you will find it dropping significantly….so I would recommend you to use 5V and not 6V for the operations.

      Reply
  67. lima toshi

    Hi, i am new to electronics, i was wondering, can i use a lm7806 not lm7805, because when i check the DC output with a multimeter of a cell phone's charger, the DC voltage is not a 5volts its 6volts, i don't want to cook my cell phone, so any help will be greatly appreciated. Thank you.

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *