2.5V Lithium "AA" sized batteries: Where to find?

[This post involves a hand held lab computer, of which this particular model was made/purchased about 15 years ago. Similar models have since been made, but without the problem I describe below.] I have a hand held lab computer (manufactured & purchased in 1990) which takes quite an unusual battery. The battery is the size of a regular "AA", but is 2.5V Lithium. The company who used to manufacture them (SAFT) no longer does so. The SAFT battery model # is "LCP 6". Picture of battery (and a regular "AA" for comparison): http://home.san.rr.com/instep/saft-lcp6.jpg (~42KB) Picture of lab computer: http://home.san.rr.com/instep/labpartner-front.jpg (~58KB) http://home.san.rr.com/instep/labpartner-back.jpg (~44KB) The company who made the lab computer still offers to refurbish the unit for a new (more readily available) lithium battery pack, but I want to avoid doing that if at all possible. They also don't have any suggestions as to where to find a 2.5V Lithium "AA" sized battery. AND -- I've Google'd high & low for an equivalent, but nothing pops up. So I've come here to ask: does anyone know if an equivalent battery exists? (And what's with the designer(s) decision to use such an obscure battery type?)