I have used the 42%. They worked fine for me, but now I use the RcExcell see photo below. My favorite by far of late is to hook up the choke with remote negating the need for an opto kill. As for regulator's I don't use them. As far as I know they don't make one that does not burn off the excess power to regulate what goes thru. Don't make much sence using a larger battery just to regulate/ burn off the excess putting it to the smaller batteryoutputwithout the regulator.