Originally Posted by KeithLuneau
It probably was stored at full charge...
I usually do a store charge on my R/C lipos, just never put much thought into this little camera one.
For anyone else wondering, the #3 lipo looks identical to the one in my #11, even the number on it was the same. The broken #3 has been sitting around over a year, the pack measured 3.8V. I soldered it in, and recorded about 5 minutes with it like it was, and it wasn't dead yet, so that's a good sign. I'm charging it now, will test later and report!
The #3 cells are the same size, but are supposedly not as much mAh capacity. It will work, but probably not as long as a healthy stock battery. I used a good high C-rated Hyperion G3 cell in mine while waiting for a replacement. it was 180 mAH and would record for only 25 min.
BTW, it is pointless to store the camera at a specific charge level because even when it is turned off the cell is still powering the internal clock. So it will eventually run down the battery no matter what. Best protection is to periodically plug in the camera to the USB port for a brief period to keep it from fully draining. The battery has an LVC/high voltage protection circuit board on it, so it should stop powering the clock before the cell is over-discharged. But the stock cells are not very high quality, and they seem to plate up and lose capacity and amp delivery much quicker that our RC hobby power lipos. And who knows how accurate the protection circuits are?