So I got this little Syma S107 RC Heli 2 years ago for Christmas, and a couple months back I picked it up and turned it on to see if it still worked. It turned on, lights flashed, but I noticed there was no lift, even when I would charge the battery for a few hours. I suspected there was battery trouble and decided to do some quick fixing.
I did a little research and found that it is a simple battery replacement on these toy RC Heli’s. Ebay is full of batteries for this toy, so just go there and order 2 batteries (like I did) for about ~3 dollars from China.
Today I got my 2 batteries, and decided to apply the fix, here are some photos:
Undo the two screws holding the plastic cockpit
In my case when I removed the cover, I could see right away the puffed up bad battery, I added the new 180mwh as a comparison.
The fix for this is to simply pull out the old battery, cut the cables as close to the battery as possible (for easy access). Just twist the new battery wires together with the old ones attached to the board. Some people online advocate soldering this, but I didn’t want to waste the time on this and just used simple electrical tape to hold the wires.
Make sure to use any remaining tape (from original battery) to hold the new one in its place. You may need to re-balance the helicopter if you find it flies uneven. Close up the cover (2 screws) and you will be all set. My battery came pre-charged and I got to fly the copter for a minute or so. Below is the final working photo.