Powersupply for phone without normal charging-option.

Hi edaboard! I have a question for you, which i suppose you will find quite easy. Since i have no expertise, but my high-school physics i hope you will be understanding

The goal of this topic is to bring back life to my old sony ericsson k700i and transfer my old pictures etc. to my new nokia. The problem is that the charger-plug on the ericsson is broken (therefore the new phone) and the battery completely empty.
So i thought that it must be possible to mix some resistors with an old power supply from my drawer and get the right voltage for my phone - but how?

I never really got the idea of ohms law in school. Of course i'm familiar with the basics of the formular, but i'm not sure how to use it. I have quite a few resistors from my granddad and i've been trying to figure it out from this app: voltage divider, but went dead in the resistance of the phone itself.

So what i've got is:

Phone battery voltage: 3,6 V
DC supply: 5 V, 2 A

What to do?

Bjørn Wiegell
(Denmark)

If you want to drop from 5 to 3.6 Volts, just add two Si diodes in series, with the correct diode polarity.

Each Si diode will drop around 0.7 volts

Don't use resistors since the phone is a dynamic load (Current consumption changing by the time).

Regards.

Thanks alot! Will i need any specifications on thoose diodes, when visiting the local electronic-pusher, or are they common standard?

Just any 1A Si diode will work, or 2A but those are more expensive.

Something like 1N4001 or equivalent

Se the following

https://pinouts.ru/CellularPhonesCables/sony_ericsson_dcu60_pinout.shtml

The above schematic means, you can use 5V directly. The current rating of your power supply is not a problem. You should not charge your battery directly. Its a Lithium Ion type battery. It needs precision control. So give the 5V using a cable to the phones data port as shown in the schematic.

eXnol said:

Se the following

https://pinouts.ru/CellularPhonesCables/sony_ericsson_dcu60_pinout.shtml

The above schematic means, you can use 5V directly. The current rating of your power supply is not a problem. You should not charge your battery directly. Its a Lithium Ion type battery. It needs precision control. So give the 5V using a cable to the phones data port as shown in the schematic.

Click to expand...

My phone is not listed in the models of this pinout. I'm not going to charge the battery, but supply the phone directly from the powersupply. Thanks anyways!

daviddlc said:

Just any 1A Si diode will work, or 2A but those are more expensive.

Something like 1N4001 or equivalent

Click to expand...

Thanks a lot! Case sealed.

Why u want to do all these?try charge the battery by putting it in any of your friends sony ericsson mobile.