Lets understand the Sony T90 first.
It uses a rechargeable Lithium battery.
The battery is rated (by Sony) for 220 images per charge.
One of the leading reviewers said they only got 90 images per charge.
Most of the "T" model Sony cameras have a very thin battery.
Those thin batteries are not looking too good.
NiMH batteries:
Your old batteries have probably lived past their prime and they should be replaced.
I suggest you get one of the "precharged" sets of NiMH AA batteries.
They are better at not losing their charge when setting idle for long periods.
Kodak sells their "precharged" at WalMart and other chain stores.
If it were me, I would replace the charger too.
Alkaline AA batteries will only last about 40 images.
But they should not lose any charge just sitting in the camera.
If they do, you likely have a camera problem.
..
I have an old Sony Cyber-Shot DSC-P72: bought it back in '05. Worked fine for 2 or three years. Then I started to notice that my NiMH
batteries weren't lasting as long as they should. If I had an afternoon of shooting pics, the
batteries would die out much earlier than in the past. Figured the batteries' life had been eroded,
so I bought new ones.
There was no improvement. The new batteries would still run out of life much sooner than they
should have. This would put me in a
position of having to use regular batteries, because in the middle of an event
like a birthday party you don't have the time or ability to recharge batteries. This is where the story gets weird.
Even regular batteries don't last as long as they should:
they die out very quickly also. Thus, it
becomes very expensive to use my camera now, because I have to carry several
batteries with me as backups - which I invariably need - and then have to
replace them with new batteries. I don't
use my camera too often, which is why I have put off buying a new one.
One final but important point: leaving the batteries in the
camera causes them to die out after a day or two. HIS NEVER USED TO HAPPEN. Furthermore, I have come across very similar
complaints about newer Cyber-Shot models such as the T-90. What is going on here?

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