Finished the festival battery this past weekend. Big Ray, yours is in the mail today at lunch, I will PM you here in a sec to verify info.
Here is the finished product, minus a carrying case, which I'm still hunting...
I got the battery on EBAY, $20 delivered, but Rat Shack has them on sale right now for $20. 4pin XLRs from MarkerTek, wire from Lowe's and the Car Adpater from Creative. That was the most expensive part - $40. I couldn't find one ont he site yesterday, not could I find batteries or remotes for the JB3.
Anyways, total cost, with the $40 adapter rather than the $15 WallyWorld model was $90:
Battery = 20
adapter = 40
XLRs = 10
etc. = 5
Charger = 15
Maybe I should have bought an Eco-Charge, but whatever... It was fun making...
Here is all the stuff minus the charger: