The need to turn on a mobile phone without a battery arises when using it as part of an alarm system. Such a system can operate in extreme temperatures that are detrimental to the battery.
Instructions
Step 1
The standard charger is designed to work in conjunction with a battery that can deliver significant current for a short time. You cannot directly power the phone from it - the voltage will drop to almost zero the first time you try to turn on the transmitter. Make or purchase a stabilized power supply that generates a voltage of 3.7 V at a load current range from 0 to 2 A. This voltage should under no circumstances exceed the specified value, including during turn-on and turn-off transients, and also in case of loss of load. The unit must be equipped with protection against short circuit, as well as overvoltage in case of malfunctions in it.
Step 2
Turn off the phone, disconnect the standard charger from it, and then remove the battery. Using a voltmeter, find two contacts near the battery that have a voltage of 3, 2 to 3, 7 V. Determine the polarity of this voltage.
Step 3
Apply voltage from the power supply, observing the polarity, to the corresponding contact springs of the phone battery compartment. Use soldering only if the device is never again planned to be used outside the security system. Connect with de-energized power supply.
Step 4
Turn on the power supply and then try turning on the phone. If this succeeds, it means that it is not equipped with a system for reading data from a chip built into the battery, which means that it is suitable for use as part of a security system. Please note that if the mains voltage is lost, the device will turn off instantly. To prevent this from happening, equip the alarm with an uninterruptible power supply located in a heated room. Having connected the device via a USB port to the security unit, the common wire of which is untied from the common wire of the device's power supply, check the operability of the system you have made.
