Ta - fitted now with connection mounted nr fans Just one small bit that wouldn't stick down onto the sump but hopefully won't become an issue although it did overheat there.
Good guess then. Fantastic amount of heat - actually glad I didn't do this to the can when it was cold (ie -19) a couple of weeks back. Good old Canadian truckers...
I used an outside christmas light extension cord as it's weather proof, routing it to the side of the battery where my jumplead and trickle points are.