OLED display--Swapping out 3.7v, 240mAh for 330mAh battery

[magnusson_r]

I have a MP4 watch with continuous-on Organic LED display which I bought on that famous auction site (search "OLED watch"). It has a 2GB capacity, and plays MP3's as well as video, in addition, so the main component is very similar to an iPod Nano.

Which brings me to my question: Can I replace the 3.7v, 240mAh battery with a 330mAh iPod Nano battery? The voltage is the same, and it is the same battery chemistry type (Li-Ion polymer) and the dimensions are the same. The battery looks identical, with same step-down component attached.

All I have to do is snip the wires (the battery is soldered directly to board) and patch the leads together and voila !! -- I get an extra 2 hours or so of runtime (right now it averages 8 hrs, with the time display continuously lit).

Any comments or cautions?

[redled]

Yes, if it's the same (physical) size and same chemistry it will work. But when you say 'step-down component' I think you're mistaken. It's most likely a thermocouple that monitors the temperature of the battery to determine amount of charge. Lithium battery's are very volatile and must be charged carefully, so heat monitoring is usually incorporated into the charging circuitry, via a thermocouple next to the battery. When you repace the cell, make sure that component is in the same place as the original and in firm contact with the surface of the cell.