When looking for a discharge like that a really easy way to check is a pigtail socket and 1156 light bulb between a battery terminal (whichever is most convenient to get to) and the battery cable.
If there is something drawing power the bulb will light up, the brighter it lights, the bigger the draw.
Then to find the culprit start taking fuses out until the light goes out, the draw is then in that circuit.
If you're working alone, a noise-maker like a back up alarm, instead of a light bulb will tell you when there's power or not.
If it's taking several days, it's not a big draw though.
Ted 'n' Laurie, plus Jackson (aka Deputy Dog, the Parson Russell Terrier 'fur kid') and, Rylie (who crossed the Rainbow Bridge June 14, 2012).