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Replacing polymer 3.7V battery with Mobile phone's battery, is it possible?

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Newbie level 3
Apr 12, 2015
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I have an old Cowon A3 mp3 player. I would like to replace the nearly dead 3.7V polymer battery (that the device can recharge) with a new one.
I found one in **broken link removed**but it seems to be too long for the player.

can I use something like **broken link removed**
any other ideas if not?


No. I'll have to fix it somehow but they are simple wires...

is there anything I should know when switching batteries? I mean, in addition to making sure that the voltage is the same on both??

If the battery voltage is the same it will probably be OK.

Things to watch for are whether the Cowon uses additional contacts to the battery. If you look at most mobile phone batteries you will see they have more than two contacts, one is positive, one is negative and the others are for data communication so the battery can report it's charge level. If the Cowon uses the communication contacts it will almost certainly not be compatible. If it just uses + and - you will be OK.

I suggest you buy a new charger for the phone battery rather than use one built into the Cowon, just in case the charge characteristics are different. You can do a lot of damage with a wrongly charged LiPo battery! Lots of sellers include a charger with the phone batteries.


Thanks a lot!

but the Cowon is charging as long as it is connected to AC.
even if I fully charge the new battery with different charger, the cowon will try to recharge it again as it connected.

should I try it or it's too risky?

It is probably OK but I accept no responsibility if something goes wrong!

Overcharging a LiPo can make it explode, that's why they have a circuit board inside a phone battery pack that monitors voltage and temperature. The Cowon may have no circuit to read the battery anyway and even if it did, it would probably talk a different language than the phone battery. If the Cowon only has two wires to it's old battery, it is probably safe to assume it charges the battery at a very slow rate to avoid damage and that slow rate should prevent damage ocurring to a new battery too.


I would expect it to work well, unless you also replaced your MP3 charger with a rapid high power charger and create more thermal losses. Otherwise, no worries.

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