Building own charger for e680i

[deswong]

Hi everyone.

I have attempted to build my own charger using a regulated power supply delivering 5V @ about 550mAh like that of the original Motorola charger.

Is there something I am missing as when I plug it in, the phone does not seem to charge. Seems to detect something plugged in with the "chirp" sound, then doesn't seem to acknowledge or charge.

I have wired it so that +5 and GND are being connected to the right connection, but is there any part inbetween that it may be looking for to recognise that it is attached to a charger?

Des.

[rhizod]

Well, something "special" is up with the charger; since my phone tells the difference between an ordinary USB and the charger USB connectors... (refuses to charge an empty battery on ordinary USB; no idea why, appears to be stupid to me).

[alebm]

You will have to check the pins of the original charger to see if other pin than +5v and ground is activated. Kernel needs to get a interrupt in the usb client controller to start the emu charger thing. May be the charger exchange some information too(but I don't think this is happening...).

[pinnacle]

E680i won't charge if we just connect +5V and GND to the phone. Here is a diagram from CCmove showing a USB cable pin assignment for E680i battery charging. Hope this helps.

Refer to the diagram (it shows the modification on mini-USB connector of a USB cable):
Pin 1 -> GND
Pin 1 - [200k resister] - Pin 2 (Put a 200k resister between Pin 1 & 2)
Pin 3 -- Pin 4 (Short circuit)
Pin 5 -> +5V

With this cable, I can charge the phone with even my PC is shutted down (use the USB standby voltage on PC USB port).

[admin]

wow. they have real hackers there man. they hack everything out

[arzme]

hmmm, i'm not so electrical.... so i'm curious as to why u guys wan to build ur own charger? didn't the phone come with a charger?

or u wan to charge using higher current? didn't tht will just make charging faster but not increase the battery power... right? heard tht faster charging can actually shorten the life span of the battery... izzit?

[deswong]

I personally was looking to build one so that I could use a solar panel (very small of course) to charge it whilst out and about.

Also because I don't want to have a bulky transformer as well, I have a small AC 5V adaptor that I could use as I don't have the 240V version of the charger available cheaply (They quoted me around $60 for a charger that "may be suitable") and have plenty of 5V supplies around (as any electrical nut does )

Thanks for the diagram, makes more sense. Maybe shorting the pins 3+4 tell the phone a charger is connected. The 200k resistor seems to be there to regulate current being delivered to the phone.

Des.

[alebm]

If my charger blow up or I lose it, I will have to spend about to 80$ in transport to import another one hahaha and moto original chargers cost more than it really worth. I prefer to build my own.

[maxx_730]

I have no idea in which country you live, but for people who have the phone where it isnt sold (eg europe), you can just buy a razr v3 one, which are sold in most (all?) countries.

[alebm]

I live in Brazil, and yeah... the razor v3 is about US$15, but I still can build one for 1/5 of this hehehe just for fun. Anyway, I already have a desk charger that I modified from an old phone and work fine for any lithium ion battery until now.

Modding these things are one of my favorite tasks hehe, take a look on what my old cellphone lcd display transformed