I just found this interesting article. I didn't know about this and if this is OFN, I'm sorry.
Check it out...
Here's a snippet for those too lazy to click...
With the news that Sony's controllers would feature built-in, nonremovable batteries, many were upset about buying what amounts to a disposable peripheral. Would it be a matter of going through controllers as the batteries died, and would we have to worry about the memory effect of rechargeable batteries?