Old but good thread.

Found these Imac B6 and Imac B6AC of ebay. This may be a good alternative to consider given that the Multiplex charger mentioned about is now apparently discontinued (I believe). The B6 model only runs off 12V, the B6 AC runs on either 115vac or 12v. It looks like Imax came out with the new plastic enclosure so the previous models are going for $35...

http://www.ebay.com/itm/iMAX-B6-AC-B...ht_2631wt_1206

In addition to charging multiple type of batteries (including Pb), the charge can be used to run a discharge test.