The battery for the Philips HeartStartXL defib is a standard one with a small indentation in the end. I think a standard one without this dent operates a microswitch so the defib knows you are using the "wrong" battery.
The official reason for this is that the batteries are checked to a higher standard......and sold at a higher price of course.
Is a similar thing occuring here either electronically or mechanically.
Robert
PS carefull use of a drill can replicate the indentation according to a sales rep for a Philips distributor when I commented on the price of batteries.
