Portable mobile charger

[ayush soni]

guyz i was thinking to make a portable mobile charger

& i have something
which i think i can use in this


its a battery charger
we have to plugin it somewhere & there is that light green thing which have a chipper (or mouth) we have to attach out battery there & it will recharge it

i was thinking about using a 9V battery as power source


so can i use it in any way ???

& if not how else i can make a portable mobile battery charger ??

in this we have to remove battery from mobile & attach it with this
i was also thinking to connect a wire which we can plug in is to mobile as we do normally


PS my english is bad sorry about it & if u didnt get me i will explain again

 

[ayush soni]

here i found something

but in this circuit there is no resistance
it can burn my mobile battery

but the good thing is its soo simple

is making a portable charger is this much easy ??

& is it useful by adding some resistors ????

 

[(*steve*)]

You should use a voltage regulator of some sort or you might damage your phone.

A resistor will not work.

 

[ayush soni]

You should use a voltage regulator of some sort or you might damage your phone.

A resistor will not work.

ohk thxx
how to connect it with voltage regulator then ??

& i want to make it simple

& can i use that charger ??
i posted some of its image above please check them

 

[ayush soni]

& i dont have voltage regulator now
so can i use transistor ??

i have BC547

 

[(*steve*)]

Well, you could, but a BC547 would probably not handle the power dissipation, and you'd still need a zener diode and a resistor to set the output voltage (a 5.6V zener and maybe a 470 ohm resistor)

 

[ayush soni]

i have a diode & i think i also have 470 ohm resister
so how to connect them ??


& did u see my first post ??
that little green thing ??
can i use it ????

 

[(*steve*)]

I have no idea what the green thing is.

But this is one way to get 5V from a 9V battery, a 5.6V zener a 470 ohm resistor and a BC547.

It's not efficient and it will probably make the transistor get really hot.

 

[ayush soni]

see this

http://www.knowcrazy.com/2011/05/usb-universal-mobile-cell-phone-battery.html

http://www.amazon.com/SODIAL-TOOGOO-Universal-Battery-Charger/dp/B002XY5F6A

it is called
Universal Battery Charger

 

[Gryd3]

Google LM7805. It's a 1A capable constant voltage source with 3 pins.
Voltage IN (From your 9V batter)
Ground (Connect negative on battery and USB socket to this pin)
Voltage Out(Connect power for USB socket to this pin.)

This part cat get hot, so you may need a heatsink, but I used this method as a last minute home-made camping charger. There are better options.

. One more thing Ayushi .
You need to stop PMing me when you have a thread with a question that is not answered right away.
We are all volunteers that choose to be on here. I joined to offer a hand to others but to also be able to learn things myself and there are many threads I'm sure I can answer that I choose not to read. This is either because it appears to be handled, or I am not willing to invest additional time into another thread.

 

[ayush soni]

. One more thing Ayushi .
You need to stop PMing me when you have a thread with a question that is not answered right away.
We are all volunteers that choose to be on here. I joined to offer a hand to others but to also be able to learn things myself and there are many threads I'm sure I can answer that I choose not to read. This is either because it appears to be handled, or I am not willing to invest additional time into another thread.

sorry about that
last time u helped me
thxx y i sent it
anyways
guyz
here one more question

i think the red one is for positive& black for negative
what about other 2 ?? white & green ??

& i tried directly connecting my phone port (in which i plug charger pin) to 9V battery
its working fine the phone is charging
but i dont know
maybe it can also damage it
what u guys say ??

 

[Gryd3]

sorry about that
last time u helped me
thxx y i sent it
anyways
guyz
here one more question

i think the red one is for positive& black for negative
what about other 2 ?? white & green ??

& i tried directly connecting my phone port (in which i plug charger pin) to 9V battery
its working fine the phone is charging
but i dont know
maybe it can also damage it
what u guys say ??

http://image.pinout.net/pinout_USB_files/usb-pinout-diagram.gif
Very bad idea to put anything other than 5V on USB.
Your phone now has to work harder to reduce the 9V, and I'm surprised it did not cook it already.

White and Green are data wires, and there are different ways of dealing with them. You can leave them disconnected, connect them to resistors, or connect them together. Depending on what you do with them, the charging device will try to pull more or less current to charge itself.

I do not know what the combinations are to get specific results though. Leaving them tied together will let almost any device charge.

 

[ayush soni]

Your phone now has to work harder to reduce the 9V, and I'm surprised it did not cook it already.

i connect it just for some seconds & also the battery is not new
so because of being used it didnt burnt my battery
& i connected those white & green wire with eachother
& dude can u tell me something about that universal charger ???



according to me when we plug it in with socket (i think which is AC) it convert it in DC filter current & charge battery
but when i tried using my 9V battery as power source it didnt worked

 

[Gryd3]

I can't give you a definate answer, because I don't know exactly how the circuit inside is bult.
I can make guesses though:

Those universal chargers are built to receive a specific input voltage, if the input voltage is too low, it may not turn on, and if the voltage is too high, you could damage it.
Devices that are meant to be powered from higher voltages like 110V or 220V will not work with a 9V battery. This could be due to the transformer in the power supply, which only works with AC, or it could be due to other protection mechanisms inside.

That amazon link shows 3 different models in the pictures... looks shadey.

Also, it is a good idea to note that directly charging a battery in the way that those devices do, requires that those devices are built properly and stop charging the battery when it is full. Cheap chargers will keep pumping power in until you remove the battery, or something pops.
Using a USB socket and a 5V regulated voltage supply (Like the LM7805) will allow your phone or other device to take care of it's own battery and is highly recommended over using 3rd party chargers.

 

[ayush soni]

Also, it is a good idea to note that directly charging a battery in the way that those devices do, requires that those devices are built properly and stop charging the battery when it is full. Cheap chargers will keep pumping power in until you remove the battery, or something pops.
Using a USB socket and a 5V regulated voltage supply (Like the LM7805) will allow your phone or other device to take care of it's own battery and is highly recommended over using 3rd party chargers.

i didnt get u properly

 

[Gryd3]

i didnt get u properly

Sorry if you did not understand.

What I said is that using a different charger may be risky. If the charger is not built properly it can damage the battery.
If the device (Cell Phone, GameBoy, Laptop, etc.) has it's own built-in charger, then it would be much safer to power the device and let it charge it's own battery.

In the case of cell phones, provide a stable 5V from something like an LM7805 to a USB socket. Then you can plug your phone into that to charge the battery. The LM7805 is a much better choice than a resistor or transistor. Never provide anything other than 5V to a USB socket, or cable, or you could cause some damage!

 

[ayush soni]

ohk thxx
i will go to market & will but LM7805

& u said "What I said is that using a different charger may be risky. If the charger is not built properly it can damage the battery."

i know
but i want to make a portable charger

 

[Gryd3]

ohk thxx
i will go to market & will but LM7805

& u said "What I said is that using a different charger may be risky. If the charger is not built properly it can damage the battery."

i know
but i want to make a portable charger

You can make a portable charger, but it is safer to NOT connect it directly to the battery.
When you use that LM7805, you can power a cell phone with a USB cable, and the cell phone will charge it's own battery.

 

[ayush soni]

ohk
will buy LM7805

& will you please guide me how to connect things ?

 

[KrisBlueNZ]

This data sheet has some good guidelines: http://www.st.com/web/en/resource/technical/document/datasheet/CD00000444.pdf

http://www.google.com/search?q=how+to+use+7805+regulator