A65 battery life/drain

Been a long time since I posted here; July 2006 according to my profile.

I have 'upgraded' my 'vintage' Sony DSC F717 to an A65 with twin lens kit two weeks ago.

I bought two extra NP-FM500H batteries (Sony brand) to go with the one that comes with the camera.

I fully charged all three before using the camera.

I was expecting to get the performance (number of images taken before a recharge) similar to the F717 batterirs and as mentioned in the A65 manual on page 80, approximately 500 images per charge.

However, the first battery I tried, the one that came with the camera, was down to 22% from a full charge after I had taken 112 images (full size 24mp)

I thought it might be just because of it's 'first use' and it will get better after a few recharge cycles.

I put the second battery in the camera a week ago, made sure it was turned off, and put the camera away and didn't use it until today.

When I turned the camera on today, I checked the battery and was shocked to find that it was down to 80% charge (from the full charge when it was put in the camera a week ago) when it hadn't been turned on or used.

I am using Sandisk 32GB SD cards rather that memory sticks, and following the settings on page 80 of the manual, I should be able to take something like 500 images before the battery needs to be recharged. This isn't happening, I seems I'll get just over 100 photos per battery charge.

If so I'm going to need more than three batteries...

My questions:

Could this be because the batteries are new and need to go through several recharge cycles to get better perfomance?

What would be draining 20% of a battery charge for the camera that is not turned on or being used in 6 days?

Compared to the batteries for my Sony DSC F717 these batteries are not performing very well at all.

The three NP-FM50 batteries I have for the F717 are still fully charging and giving 200 minutes continuous (400 - 500 photos) use after 9 years of regular use and being charged monthly...

Other than that the camera is great...

--

A hundredth of a second here, a hundredth of a second there—even if you put them end to end, they still only add up to one, two, perhaps three seconds, snatched from eternity.
Robert Doisneau, French Photographer.