Another Camry Stalling Problem

[Skipraider]

The Battery on my dads Camry died the other week, and was left for a few days until another Battery was sourced. We have now changed the Battery but now stalls when idling - the revs are just too low. It will keep runing if you have the AC on as this raises the revs slightly. I read somewhere that the ECU has to 'learn' to idle again but we tried letting it idle from cold, but started stalling when it got warmer.

Any ideas what this could be?

Cheers!