I want to hack my portable device, so that it does not use lipo battery anymore. I want to have it using just external power supply (don't ask for reasons).
Unfortunately after disassembling the device and removing lipo battery, the device does not work anymore. When connected to 5V DC the red led flashes, as if it was to inform me that lipo battery is dead.
No other functionality of the device is working.
That bring me to the question: What is the best way of fooling device that lipo battery is connected? The device obviously wants to charge the battery if it has low voltage.
My ideas so far are:
connect 4.2V DC directly to the place where battery was connected (how to get 4.2V, having 5V (USB) as input voltage)
be brave and connect 5V and hope that internal voltage regulator will not blow up and that none of the red-flashing-diode fail safe will not kick in.