Back to the original thread -
When you change batteries, what prevents you from accidently putting the crocodile clips on the wrong terminals - anything?
The controller thread within the original thread.
Winproclean is set in his ways on this one. Peter is talking sense. (and yes I go back far enough to remember using Peter's "useless" on off remote with my trolley system

)
I dropped a flow controller years ago - waste of time and money. I use a tap on my belt between the end of the reel hose and where the pole hose clips in.
So I've tried a remote; a controller; a tap on the belt.