Let's Make Robots!

why won't my phone charge?



Just kidding. This is scraping the bottom of relevancy though.

Could you perhaps point me to a good documentation source for charging a 3.6 V battery in an old Nokia? Or could you solve my problem directly for me?

My dad is about to go walkabout in the south of Europe. He bought a 12 V photovoltaic power source that folds like a wallet. He seeks my help on the simple stuff, like mechanical compatibility of connectors and pinouts. And soldering.

That's the easy stuff. I managed to hook up V+ and GND correctly to the phone. But it still won't charge. It obviously knows what I am trying to do, but teases me with one liners like "please reconnect the charger". Like that would do any good.

So, unless you already linked me the right pdf or DIY phone community, let's make Nokia charging robots!

I noticed the original charger uses three wires in its cable. Red, Black and Brown. The charger puts out V+ (6.2 V nominal) onto red and brown when not plugged into the phone. Any ideas what the function is for this extra wire?

I am also concerned with the varying output voltage of my source. Depending on light exposure it will produce anywhere between 0 and 15V. It is rated as 12 V and some 433 mA. Would the Nokia protect itself against anything higher than 6.2 V? Is this the reason I am failing here? Should I put in a regulator? Should it be 6.2 V or 3.6 V ?

And first off: would that convince my phone to accept the charge?
And way after that: what about efficiency?

Any help appreciated.

Update: found the model in image search: it's in the 3300 family. Probably a 3310.

Nokia 3310

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The model number is under the battery. Your picture looks just like the 3310 that I use every day.

Thanks for the tip about the hidden label.

You recognising a picture I plucked from the nets isn't gonna identify the phone in my dad's pocket. I don't have it with me, never photographed it. Just recognised this photo as probably being the same model. Same family (3300's) anyway.



How bizzare, why woukd they have that do you think?  

I also learned that these batteries have a termometer onboard. One of the pins can be read as an thermistor. Maybe the phone can throttle the charger if it gets too hot?

Question remains: how do I fool it? Do I need to?

Check http://pinouts.ru/CellularPhones-Nokia/nokia_5110_6110_pinout.shtml .

Could it really be the case that a Nokia uses some PWM signal over the third (brown) wire? What for?


full DLR-3 pinout. applicable to 51xx, 61xx, 62xx, 63xx series?

Pin Description
3 XMIC MIC INPUT 60mV - 1V (also Device Selector)
5 XEAR EAR OUTPUT 80mV - 1V (also DLR-3 RTS)
6 MBUS 9600 B/S
7 FBUS_RX 9.6 - 230.4 KB/S
8 FBUS_TX 9.6 - 230.4 KB/S


The "base plate" of a 3310 - if that's what your dad has - doesn't look like that. I can't take the charger apart - it requires some wierd three legged screwdrived - but the plug looks to be a simple two wire - inner and outer. The data plate says "3.7V=/355mA", and its model number is "ACP-7X", which generates loads of Google hits

Thanks for the detail. That should help me google indeed. The base plate I showed before is from a 6310i which I am using as a substitute. In hindsight: I should've given my dad the 6310i and keep hacking on the really old 3310.

Chances are however, he will never make the reverse swap after I'm done. And I get stuck with an antique. Hmmm, roborik might like that....

Found this for a car charger circuit, just a well filtered 7805.

Looking for someone's DIY circuit that's reported to work. That will help. Even if the maker describes flaws. It's descriptions like that I'm after.

For example, this taught me that a 8210 will accept regular two wire 5 V supply. That might be true for my phone, even if it's a different model. And it is hinting at the efficiency issue. He suggests burning off a few Watts before heating up the poor little 7805.

Once I prove that my model (still need to find its number) will also accept 5 V straight up (so far no good), I'll dive into oddbot's tutorial on power conversion done right.