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Showing results 1 to 25 of 26 @ 0.67 seconds. Search: Posts Made By: foxOnTheRun
Forum: Accessories 2013-08-21, 09:54
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

Nope, the somewhat integrated charging algorithm would refuse or badly/wrongly charge the batteries. I remember the charge in the XM5800 shows a pulsed profile when checked at the battery terminals....
Forum: Accessories 2013-08-21, 09:45
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

Still alive and kicking ;)

Safety: yes, electricity and chemical reactions involved mmmhhhh sweeet! Sure, leaving the *test* charger on a cardboard box over the sintetic rug on the wooden floor.....
Forum: Accessories 2013-01-15, 17:39
Replies: 18
Views: 24,275
Posted By foxOnTheRun
Re: Nokia external battery charger?

If still interested, I'm having some interesting results, see last post of http://talk.maemo.org/showthread.php?t=73600 ;)
Forum: Accessories 2013-01-15, 17:05
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

So, long time no see :o

Here (link to google sheet) (https://docs.google.com/spreadsheet/ccc?key=0Av1szz1chF85dHNwZTZMcDZzWTRQUGFtNUNaYU04MVE) you can take a look at the performances of different...
Forum: Accessories 2011-09-24, 14:10
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

Thanks!

Ooppss! Sorry! the summer was good enough to scramble all my habits ;) - but I kept working on it in a steady manner ;)

The charger has reached a decent working stage! Hardware hasn't...
Forum: Accessories 2011-07-30, 11:47
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

Uhmm.. the answer to your question would be: copy the chinese charger :) - it has just 2 transistors and the voltage reference IC, it works only looking at the voltage, the finalizing charge current...
Forum: Accessories 2011-07-22, 15:07
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

98% ready!

Here's the pic of it charging a standard cell, on the left, the grey thingh.

http://img692.imageshack.us/img692/893/22072011154.jpg...
Forum: Accessories 2011-07-19, 12:25
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

Charger il 97% done, I've lost some time with a differential amp with a soul on it's own, voltage trimming here and there and some issue with an old Lithium cell with an higher than expected...
Forum: Accessories 2011-06-17, 17:50
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

To get back in the topic, about the charger.

I put an objctive: NO fancy ICs. The one I mentioned at the beginning, the Maxim one, fully integrated, automatic cycles, 5 pin to solder.. puah! too...
Forum: Accessories 2011-06-17, 17:44
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

Gosh! :D

And it's a portable-battery-powered one!!

In my room!! that would be the nerdiest thing ever happened!! I can forget the story of the talking frog so ;)

P.S. That was an engineering...
Forum: Accessories 2011-06-17, 17:41
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

At first you could read the voltage applyed on the battery, just make contact with the internal pins of the battery - Nokia charger at the end of charge is applying a pulse charge profile.

Not yet...
Forum: Accessories 2011-06-17, 17:39
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

Ok, I'm assembling a quick and dirty temp sensor with an LM35, a PIC and a display, this would solve the mistery.

But, I can *triple* assure you that, among 7-8 batteries I have, when they are...
Forum: Accessories 2011-06-16, 15:52
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

Some updates!

I just bought 6 different BL-5J batteries :D So I have "meat" to feed my developing charger without blowing up the good original battery.

BUT, I'm having soma strange behaviour...
Forum: Accessories 2011-06-04, 23:04
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

A smart one!! the smartest-never-seen-before... :D

I've read some suggestion here and there, nothing of professional but:

_there are several IC that would already do the job, one over all the...
Forum: Accessories 2011-06-04, 15:27
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

Some other updates.

Before starting the design of a new charger (just for phun) I found a nice trick to pimp this charger.

I was stuck in increasing the efficiency of the circuit given fixed...
Forum: Accessories 2011-06-04, 11:47
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

True! I was reading that when charge current drops below 3% of C-rated, the battery is full - where C is the amp/hour capacity of the battery.

So 3% of 1320mAh is 39mAh.. but this ""charger""...
Forum: Accessories 2011-06-03, 20:03
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

The other thread is over 70 pages long! gosh :eek:

Did you post some schema/circuits? I've read the first posts, nice work with those batteries :D - I was thinking that the 5800 was subdimensioned...
Forum: Accessories 2011-06-02, 22:53
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

Well, I'll post the final trace of the circuit in a short time (aka.. when I can finish it), even if some details does seem to not match (starting current, final current) - I think my multimeter is...
Forum: Accessories 2011-06-02, 22:32
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

The major problems with my unit was the total lack of quality into the assembly: defective wires, less than perfect solders were the main problems.

I'm working now in refining the circuit traces...
Forum: Accessories 2011-06-02, 09:30
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Cheap (chinese) external BL-5J (and other models) battery charger: reverse engineering

Howdy!

New update: revised and corrected schema, 98% sure it's right.. for now ;)

http://img830.imageshack.us/img830/9210/schemax.th.png (http://img830.imageshack.us/i/schemax.png/)

Full...
Forum: Accessories 2011-06-01, 12:27
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Chap external BL-5J (and other) battery charger: reverse engineering

Ops, you are perfectly right! (http://en.wikipedia.org/wiki/Electronic_color_code) - when I googled I wrongly took the first page that showed that strange value "180pF"..

I'm finding an incredible...
Forum: Accessories 2011-05-31, 20:02
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Chap external BL-5J (and other) battery charger: reverse engineering

Yep, mine got both, a variation of a mini usb + the cable in the picture.

Are you sure about the cap value? where you referring to yours or mine?
Forum: Accessories 2011-05-31, 20:00
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Chap external BL-5J (and other) battery charger: reverse engineering

All right, here are the latest news:

The latest circuit is this:

http://img38.imageshack.us/img38/1665/circuit11.png (http://imageshack.us/photo/my-images/38/circuit11.png/)

Full size:...
Forum: Accessories 2011-05-31, 09:07
Replies: 45
Views: 50,989
Posted By foxOnTheRun
Re: Chap external BL-5J (and other) battery charger: reverse engineering

UPDATE I'm finding some errors in the circuit tracing, I'm working on the new schema, meanwhile I'm posting a new image of the back of the PCB without the pen marking.
...
Forum: Accessories 2011-05-31, 07:48
Replies: 18
Views: 24,275
Posted By foxOnTheRun
Re: Nokia external battery charger?

Talk about cheap external chragers:

http://talk.maemo.org/showthread.php?p=1018788#post1018788

Bought off ebay for 1.99 GBP (shipping included), right now I'm trying to trace, simulate and...
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