I massive box of wireless security system modules came in for recycling and they ALL use the same 3.6v cells that Apple used for their PRAM batteries. In total I was able to harvest 38 cells that were still holding a voltage above 3.5V which is good enough.

Currently using some of them as a form of currency to pay people to do jobs for me. All my macs though are happy now that they don't need to hassle with my CR2032 adapters.