Never have replaced a battery in them. I have seen people do it, but no word on the life time of the replacement.
getting a replacement can be a hassle. not all PS3 controllers have the same battery in them. and the ones you can get range from ok-ish to outright not working - if they fit (different physical sizes)
My brother finally tried his custom Xbox one s controller and I was ready to setup the Bluetooth only to realize he still have Windows 8.1. I still tried to connect it via Bluetooth, and strangely it works (even if in the Bluetooth manager it's shown as the drivers are still being install) and with a little fiddling around in Dolphin there is no problem.
Well, as it is, i've got my PS3 controller working. Installing GTA 5 atm, and it's a pain... wish i started hours earlier. SHIT SUCKS!
BUT, if it comes to that, i'll probably get a Steam Controller. Seems like the way to go. I only wish Valve would release a revision of it already.
And please, guys. If you can, help me out in my GTA thread. I've got sort of a situation with GTA 5. I feel like doing something for someone, and i hope my idea works.
Didn't read it all but, well ... I'm using the PS4 controller.
Works over bluetooth with basically any bt-adapter, has a good battery, is robust and dual shocks are my preferred layout anyway.
As far as what good gaming controllers to use on the PC, I currently use my DS3 controller by way of Mayflash adapter and it was the best decision. I hate having to deal w/ any drivers/software compatibility BS and it rid me of that headache. Hell, I went ahead and bought 2. Also, I've been using the XBox 1 controller lately and it's quite a beast... way better than Xbox 360 version in every way.