Phone charger from 9 V battery

This tutorial will show you how you can get 5V USB from a 9V battery and use it to charge your mobile phone.
The photo shows the assembled circuit in action, but this is not the final version, since I will also make a housing for it at the end.
So let's start making it.

Materials

The photo shows the components necessary to assemble the charger, including one empty case from an old battery, in which the device will be built.
Components and materials:

Old battery for the case.
USB port.
Regulator chip 7805.
One green Light-emitting diode.
Resistors 220R - 3 pcs.
Solder.
Wires.

Scheme

The diagram shows the pinout of the 7805 regulator, the USB connector and the actual circuit of the simple converter.

Assembling the charger according to the diagram

After disassembling the old battery, parts can be soldered to the base with the connector. Everything is assembled in five minutes, and I think that nothing needs explanation, except for the resistors connected to the middle USB contacts - Data+ and Data-. And they are needed so that the cell phone itself understands that it is connected to a charger, and not to a computer for data transfer.
The circuit does not require any settings and starts working immediately.
Light-emitting diode indicates the presence of charging current flowing. If it is not lit, it means the battery is completely discharged or the phone is fully charged.

Ready converter

The picture shows a view of the finished device in its housing. The mini-charger is convenient to carry in your pocket since it is very small, and together with the battery.
Original article in English

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Comments (13)

#1 Victor Guests 14 February 2018 09:15
6

Let the battery cost about 100 rubles. This is the price of one charge. It’s easier to buy a lithium-ion 18650. They are becoming more affordable in price. I didn’t understand about the LED, a current passing through it is greater than its operating current.
- Answer
#2 Punch9 Guests February 16, 2018 09:58
7

Is it okay that the charge current of this device will be 20mA? That's exactly how much he'll let through. Light-emitting diode.
- Answer
#3 Alesey Guests 16 February 2018 18:12
2

How much power do you want to squeeze out of this battery?
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#4 Isn't it Guests 18 February 2018 07:18
4

The author is clearly inadequate. Don't even try to sculpt something like that. To charge the phone once you need about 15 batteries. And 40 hours of charging time.Since the current in the crown is very small, and I’m generally silent about ampere hours..
- Answer
#5 Guest Oleg Guests 14 March 2018 14:00
1

Really some kind of canoe. The thing that takes us back to the Stone Age. It would be better if they showed charging from the WI-FI signal.
- Answer
#6 Guest Oleg Guests 14 March 2018 14:05
1

A 12 volt circuit is better. So at least you can get a charge from the car. Although there are plenty of ready-made devices on sale. What's the topic?
- Answer
#7 Audio Man Guests March 12, 2019 01:41
3

The circuit will charge normally if you do not use those resistors that are connected to pins 2 and 3 of the USB plug. From the crown, the charging current is 480mA. The author is not inadequate - the scheme is simply unfinished.
- Answer
#8 Alexei Guests 10 April 2019 22:27
3

I have a 4000mA phone and how many batteries do I need??? There aren’t that many in the store, why two resistors on the date bus??? the phone will understand without them that there is only a leak while charging, and everything is through Light-emitting diode this is actually an epicrisis
- Answer
#9 Guest Vitaly Guests June 30, 2019 01:01
2

I understood the idea - an analogy with a transformer: high voltage at low current is converted to low voltage at high current. Let's say. You just need to take into account that the Krenka 7805 has a maximum output current of 0.5 A. Only push-button phones can be charged this way.
- Answer
1. #10 Acelot Guests 18 November 2019 23:33
  1
  
  Maybe the current is 1.5 Amps? Bo I know that it is not 0.5 Ampere
  
  Answer
#11 Guest Alexey Guests 24 August 2019 22:30
0

And how much more energy in the form of dissipation on the bank itself will go to waste? It would be better to use a pulse stabilizer rather than a linear one. Even in this case, charging a modern smartphone requires almost fifty crowns. Expensive. Power bank is cheaper.
- Answer