My horse is due to foal any day now, so I bought a wireless CCTV system so I
could keep an eye on her. I specifically needed one that could run off a
battery as there is no power in the stable.

I set it all up and it worked fine for a few minutes, then it stopped, and
it looks as though the camera battery has run out. It was also supplied
with an adaptor, which says Output 8V - 500mA. Well as the rechargeable
batteries I have are 160mAh, would I be right in thinking that these
batteries will last all of about 20 minutes?? If so, I'm absolutely
seething, that's no good at all. I'm waiting for a response off the company
that sold me the kit (they know exactly what it was being used for...)

Is there any way I can get the camera to run off a 12v leisure battery
instead?

Cheers.