Thanks for all your replies, lots to look into regarding the above suggestions (all of which at first glance seem to be a better set up than mine!). I'll have a go at all of these, many thanks.
The pad draws approx. 700mA of current according to a Sparkfun tutorial I watched. That was from a power supply at 5v rather than a battery.
Appreciate your time and comments guys.
Best wishes
Phil