Try the battery reset...lifted from Nick T's:
"Here's how to reset an H battery if it is not holding a charge or not lasting as long as it should.
Note this works with the newer 7.2 volt batteries and not the older (9.6 v from memory) ones.
First Charge the battery fully, preferably overnight.
Then grab an H body with no battery on it and press and hold the "menu" and "flash" buttons, and while holding them down push the battery up onto the handgrip. You should then here a rapid series of beeps indicating the PMU on the battery has been reset. Now put the battery back on charge and it should improve performance.
On a side note new batteries will have a low initial capacity, cycle them through charge discharge (on the camera) a few times to get full capacity."
Not sure about 5d2 batteries, but the H batteries last no where as long as the 1D3 batteries I had.