I have a 2011
JCW and I get a spark when I re-connect the battery terminal if I need to remove it for anything. I think this must be normal as I dont have any problems with mine. I wonder if its the amp for the HK stereo as this does stay on for a few min after the car is switched off I think. So I wonder if it comes on when the battery is connected then goes off again when it times out possibly.
May I ask whats the problem is your battery going flat ? When you say 10v of draw i dont understand what you mean as draw is current and this is calculated in amps not volts.
How old is your battery could it just be an exhausted battery . Could you need a new battery?