Just to add another thought to the flatulence issue, I stopped and locked mine recently and was leaning on it talking to someone when I felt it go down about half an inch accompanied by a slight hiss. I assumed this was part of a process to relieve a bit of pressure in the system. Had no issues with battery charge before or since. Robin
2008 Range Rover Sport TDV8
Gone:
Jaguar S-Type V8 4.2 Sport
MGZTT 190 2.5

Yes Eaters, i do agree with you. letting out a bit of air seems to be normal. been doing some reading and just seems to be normal.

just a quick update, the battery that i replaced last week, the lead acid one, was gassing. i know it sounds funny, farts and gas, i could not make this stuff up if i tried. back to the battery shop, they were deeply apologetic. they offered me an AGM battery as an upgrade for a mere $50 from my pocket. i thought that was very fair considering the actual price difference is more than $120. drove it all day and all seems to be fine.
Cheers Neil