For previous discussions see:

Just in case anyone was wondering, the ECB on a Model 2200 StorageWorks
controller shelf use the same cells and configuration. You can buy
individual cells from Portable Power Systems (here: ) or a
built-up replacement from MDS (here: )

Note this is not a recommendation for either of these two companies as
I have not yet purchsed from either, but I will be soon. This is just
a bit of additional information.

Many thanks to the original poster, Duncan Brown, for being the first
to cut one of these open and post the information.