The yellow cased Maxx sold by Wal-Mart is made by Johnson Controls.
http://www.johnsoncontrols.com/annualreports/2000/pg10.htm
You folks need to read the Renntech.org link if you have not done so already and need a replacement battery.
Johnson Controls is a very big company and sells stuff under many different names and at many different retail locations.
Now I'm going to have to go to Wal-Mart with my camera...