V-Amp 3 Loses Edited Patches

Hello. I tracked down a V-Amp 3 a few years ago after seeing it in a video or talked about on a podcast. I love it. Hands down it's better than the Line 6 POD, Zoom 3000 and other vintage processors that I have or played through.  


Anyway, I am losing my custom edits. In fact, when I power it on, it doesn't even have the factory presets. I have to restore it to default factory settings when I turn it on. I can edit the patches and save it to a bank while the unit is on. However when I turn it off, every edited setting is gone when I turn it back on. 


I've left the unit on for a few hours to see if there was some kind of internal battery that needed to be charged but that did not resolve the problem. Is there an internal battery that needs to be replaced ? I haven't been able to find any information regarding this problem.