Little mini-teardown: Air Mattress DC PUMP

[RJSV]

   Just so that you don't have to;  I've got the pictures, insides of a 3.7 Volt DC air pump, for camping mattress.
   On the left is a lithium battery; at
2000 mA-hrs.  Switch is on right of photo.  With a small control board with medium sized pwr transistor, that handles the charging over USB mini 5 volts.  Sorry, that's likely not the exact term, for doing charging off of a wall wart.
   Spec. is saying takes about 4 hours to charge.
Also, the fan-air pump motor should only be run for 6 minutes at a time, due to heating.