My bro uses Mobil 1, but gear box oil should work. My mate even used that Wynn’s Friction Proofing stuff (good shit,really works). I dont think it matters really, as long as its not like home brand oil or something, and it should be pretty thin too. If you crack the chrager open the oil is only there to lubricate the 2 gears, and not the rotor which are teflon coated anyway (acts as a lubricant????). I could be wrong.
If im pulling shit out my arse like Troyboy and my theroy blows the thing up, theres a spare charger in the shed