DS4 back button attachment. Thats why DS4 drains battery so fast even when off with this snapped.
When I bought back button attachments (2 pcs) and snapped it on my DS4 (also 2 pcs) I saw that battery starts drains so fast when controller is turned off.
I tried to search something in the net, but there is nothing about it. Everyone tells you that it drains battery faster when you play with it, thats normal, but noone that id drains battery when ds4 is turned off.
So i tried to measure currents consumed by this attachment.
When DS4 is turned off without backbutton attachment it consumes 0.14mA.
But when backbutton attachment is snapped in, but DS4 is still off it consumes 1.20mA. So it's almost 10x more.
This is why our controllers drains battery so fast (about 2 weeks) even when off.
I tested it on two controllers and two attachments so it's confirmed. #games source