Finally converted my bat files, analysed them and compared to the files that came with the software, and .... I think they were Pipistrelles. I've attached the scan below, and the rapid regular signals with the frequency around 45Khz I think is typical. Its fun to hear and see the sound of them hunting and then the bat give a blast of ultrasound to get the prey. Here's the sample from the scan software with my comments on top.
Anyone with more (ie any) experience who can comment pls pitch in.