Its been a long time coming but they are finally hitting the streets. 3rd party batteries are available for the M3, T6i/s and any camera using the LP-E17 battery pack. They are on ebay for $17 with a charger.
Before celebrating not having to spend $50-60 for a Canon battery you need to be aware of two things. These 3rd party batteries do not communicate with the camera body so no battery level displayed on the camera and a 3rd party battery will not charge in the OEM Canon charger. You will need a non Canon charger so make sure to order one with the battery. The aftermarket charger will also charge the OEM Canon battery as well. Perhaps these issues will be resolved later. Its just nice to have a few spares for the M3 that don't cost a third of the camera body.
I do not keep up with all cameras that use the LP-E17. This is a list of compatible cameras from an ebay auction:
Canon EOS M3
Canon EOS 750D
Canon EOS 760D
Canon EOS 8000D
Canon EOS Kiss X8i
Canon EOS Rebel T6i
Canon EOS Rebel T6s
