My Magic TrackPad 2 Lithium Ion Polymer battery swelled to the point where it detached the bottom polymer (styrene?) plate of the unit!
Before the battery bag slits and the battery possibly catches fire I decide to remove it form the unit. I detached the plug unit from the circuit board and the bottom plate was free A little glue softener allowed the three patches of double stick tap holding the battery to a black aluminized heat sink on the bottom plate to detach and the battery is free.
I discovered an interesting thing about the trackpad2 when I put the bottom plate back on (without a battery) and plugged it in to my keyboard. It works perfectly with the exception that I am getting a low battery symbol beside the Bluetooth rune on dashboard.
This means that if you are willing to "carefully" remove the lithium ion polymer ion Battery (time bomb) from your Magic Trackpad 2 you can go on using it as a plugin device just not as a stand alone wireless device. Why Apple saw the need to do away with the 2 AA batteries in the old Trackpad for the lithium ion polymer battery is beyond me (except perhaps that the engineers though it was cool).
Anybody got a source for a replacement for a TIS 2217-2548 3.78Vdc 2024mAh Apple Japan battery in the USA or at least short of the PRC gray market?