At a quick guess:
P- Power negative (both)
TH - Thermistor
SCL - Serial clock
SDA - Serial data
P+ Power positive
NC - no connection
Not USB -
Try I2C (batteries often are).
And most likely, referenced to P- (negative ground system).
Also -
Check out geekmaster's posts on battery teardown and replacement with non-Amazon batteries.
If you had a jail broken Oasis to plug it into -
There are standard cli tools for reading the I2C devices installed in the system.