So I know the BLX185 is rated for 4s-6s, and so is the HobbyWing Quickrun. However, I have also seen a lot of people talking about running their 4s ESC's on 2s to slow the RC down for kids...
Has anyone tried to run the BLX185 on 2s? I am thinking I would like to get a Senton, but I would want to run it on 2s, with a proper SCT motor.
If you give me enough time, I'll test it for you. However that said based on my understanding of ESCs and technology there is no 'harm' driving on reduced cell counts. Ultimately the motor's top RPMs are highly dependent upon the pack's voltage, so a lower voltage pack means less top-RPMs.
The main items I am unsure about would be:
The ESC's LVC may not adapt to a low cell count. If the ESC expects only 4S-6S, and sets the LVC based on the starting voltage (i.e. it sees 16.8v so it sets LVC for 4S at 12.8v), it may not be able/willing/capable of seeing a 8.4v 2S starting pack and setting the appropriate 6.2v LVC, instead simply being unwilling to run possibly under the assumption you've installed a way under-charged 4S pack.
I believe the BLX185 ESC provides BEC via a switching mode regulator, which controls voltage used by the Rx and Servos, in which case I would have no concerns. If however an ESC provided BEC via a linear voltage regulator (typically older or cheaper ESCs), I would be worried about high-current draws dropping the working voltage so low the servo is 'useless' or worse, the Rx cuts out.