Batteries have a "shelf life" and if rarely used ie. left uncharged, that could have knackered them.
Are they normal ones (eg. AA) or special ones that only fit that camera ?
Either way, it's possible that the charger is knackered (LOL people don't use that word enough).
The charger works, well the light comes on. They're special rechargeable batteries for the camera. I think a knacker is a person who clears sick horses, that's who I threaten to call when the OH complains of a bad back.
How strong are the batteries? They come in different strengths and you need quite high powered ones for cameras. When my usual ones ran out I stuck some ordinary batteries in and they lasted about 5 minutes!
Rechargeable batteries thrive on being used - if you've left them unused for several months, they probably need replacement ( either more high capacity rechargeables or throw-away lithium ions).
I've found either 2500mah or 2700mah work best in digital cameras. Ni-MH last well and don't seem to have a "memory" so can be recharged when partially flat unlike NiCad which must be fully discharged before charging and don't last as long.