Batteries or Charger fault?

[Sith Zombie]

Hi all!
Need a bit of advice please on my battery/charger situation.

When charging my 2 batteries [40d], the charger goes through all the light blinking i.e. 1 blink, 2 blinks, 3 blinks then continuous.
It does this in about 20mins which seems a bit quick and then when I put them in the camera they display as full for a minute then drop to 'low'.
I'm wondering if anybody knows what is happening? I'm thinking it's the charger not charging properly since this is happening on both batteries but they are the same age and getting on bit [6 years], maybe they lost their charge?
I can't test them out on anyone else's gear because they have different batteries for their bodies.

Anyway thanks in advance

 

[Mt Spokane Photography]

As batteries get older, they die by having less capacity. This means they charge faster and discharge faster. If you have third party batteries, they commonly die in a month or two.
In any event, try a new battery.

 

[Sith Zombie]

Ok thanks
They're Canon batteries but like I said, they're getting on a bit. Must be at least 5 years old. I'll replace them with a new Canon one.

 

[SwissBear]

wikipedia tells me that the 40D uses lithium ion batteries - and these babies go downhill after 2 years/500 cycles (rule of thumb )

So a new one might not really solve the problem as this two year limit begins when it leaves the factory.
Try to find out the production date...