cell phone battery + Creative Muvo 256mb

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Joined: Jan 19 2005 - 23:30
cell phone battery + Creative Muvo 256mb

I had an old nokia 3.7v lithium ion battery kickin around doin nothing so i decided to take it apart. inside is a small charging circuit with a cell. i found out the polarity of the terminals with a multimeter and found it at a voltage of 3.9v after not even being used for over a year! this is well within the limits of lithium ion batteries tolerance of 3v to 4.2v.

I also had this MP3 player kickin around that i had lost the external battery pack to, because this also doubles as a jump drive. i pluged this into a usb extension cable with 5v going to it and sure enough it powered right up! since the original battery was only a single "AAA" battery, this Must have some type of voltage regulator inside of it.

I took my usb extension cable and cut about 2" off the female end so i could solder this to the battery and i soldered the other end to a 5v power source. with the charging circuit on the battery already it keeps it within limits of voltage and heat, and runs the MP3 player WAAAAY longer then a single "AAA" battery. i insulated everything as best i could so i have a battery with a female USB plug on it and and a charger with a male USB end on it.

I made this because my job is very fast paced and my mini-disc player is a little too big and lunky to be running around with in a pocket.

i only thought of doing all of this an hour ago, so i fired of the soldering iron and let it rip. pretty cool eh?

to all would be experimental people, keep in mind, not all lithium batteries have a charging circuit on them and they can go up in flames in a heartbeat if mis-charged or discharged!!!! Point here is if your going to experiment, make sure you know how lithium batteries work and do all in a controlled environment to be safe in case of failure.

TheUltimateMacUser's picture
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Last seen: 6 months 1 week ago
Joined: Jan 28 2004 - 12:14
hmmm

I do have 2 batterys laying around from my now disposed of samsung cell phone.
i wonder if i can do anything usefull w/ them. downside is, i have no charger (the phone was the charger, and the phone died and was disposed of)

even if i cant do something usefull w. them, i wonder if i can do something cool (read: possibly dangerous, but really really awesome) with them!

DrBunsen's picture
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Last seen: 4 years 1 month ago
Joined: Dec 20 2003 - 10:38
Sweet! submit it to hackaday

Sweet! submit it to hackaday with some photos.

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