A single 1s Lipo cell is sufficient for most of the new RC receivers. You can easily make it on your own.
All you need is
- a 1s lipo
- a receiver battery cable
- soldering iron
- soldering tin
Step 1: Soldering
- solder the receiver battery cable to - and + of the 1s lipo
- Be careful not to overheat the lipo when soldering!