I checked the bit at the back of the Standard (General guidance and rationale) and discussed it with Justin. The bit at the back seems to indicate that TRANSPORTABLE EXTERNAL ELECTRICAL POWER SOURCE is not a typo, it's just not defined anywhere. It most probably applies to the dc supply from an ambulance/helicopter or from any battery supply that can be attached to the incubator.
The specific device in question (which I'm not going to name at this point until I've brought it up with the manufacturer) does have additional battery packs available to last up to 2hrs, and it has been passed by a Notified Body (and a very nice certificate it is too). The 15mins is definitely not a typo in the manual as it's repeated elsewhere. (Personally I can think of many things that I would do with a chocolate teapot - and most of them don't inclue tea! OK, maybe only one thing.) The Standard seems to imply that the integral battery supply only has to support the external source for 90min, not run it alone.
However, we've agreed that it's not clear and I'm going to bring it up with BSI.
Sue
