Mobile phone changed to landline

Based on several purposes

1, battery is not good, mobile phone parts intact.

2. Long-time navigation required

3. No SIM card required

Turn the obsolete phone into a portable navigation machine.

Basic ideas:

Disassemble the battery, obtain the circuit protection Board, reduce the voltage to 4.2v, the current 1 A, plus the capacitor to regulate the role of the switch, can do the battery (external) and external power supply synchronous use, external power is compatible with 18650 and on-board power, consider portability.

-----------------Circuit Design----------------------

(In preparation)

------------------Tool Preparation---------------------

Multimeter, soldering iron, Hot melt Adhesive, 5k resistor, capacitance, etc.

-----------------Process Steps----------------------

Waiting to be prepared

Mobile phone changed to landline