I saw a post about these batteries on the EVDL and did some digging:
They are nice, compact, 9 pound units rated at 9Ah/24V. Each cell is being quoted around $250 for the cell alone and about $275 with a regulator. Just to follow my prior indexing idea:
INDEX $3.47/Ah @ 3V.These cells are reportedly rated for 2,000 cycles and you can run them down to high DOD levels without wrecking them.
http://www.nilar.com/index.php?pageID=33&languageID=1