As you all probably know, the Lion battery for the Zodiac has a limited shelf life. In fact, my zod was only good for 20 minutes before a recharge was needed. However...
I found an eBay dealer in new Lion batteries. The wait time was some 3 weeks (comes from the Far East).
Swapping batteries was simple. Using a small eyeclass screw-driver (the installed screws are the torvex type, but too small for my torvex screw-driver), I was able to remove the screws & back and easily swap the batteries. In fact, the same tiny screwdriver allowed me to separate the back & unplug the the old battery. Putting it altogether was a snap!
So, if'n you want to extend the charge on your zod, get the battery!
Have a look in the forums at tapland.com in the General Discussion and Unofficial Tech Support sections--lots of recommendations there. I bought two LG 2000 mAh batteries recently from a seller there and it now takes well over 5 hours of heavy use to bring the battery down to 30%. The original battery was, like Terry's, down to about 20 minutes' useful life.
I think my batteries took around a week and a half (mailed from Macau).