Dad asked me to solder a cable to the broken microUSB connector, but it's totally broken and it's really hard to solder it that way, so I want to solder a cable directly to the battery connector and completely remove the battery from the tablet since the battery won't be in use. Will the circuit take those 5V from the USB or should I find like a 4V power supply?
Electronic – solder 5V USB to a tablet battery connector
batteriespower supplyusb
Best Answer
In the past while debugging power management on portable SOCs, I have removed the lithium ion battery, connected a power supply with logging capability, and then connected the battery thermistor so that the PMIC still thinks the battery is present. You do need to provide the correct voltage, or else the PMIC may think the battery is catastrophically over voltage and turn off. Without knowledge of your specific device, I cannot tell you definitively if this will work for you, but it is plausible.
It may still be better to use the USB connector however. You can ignore the data pins, so it is often very simple to desolder the existing broken connector, and then find somewhere under it where the +5 and GND traces are accessible even if the traces have lifted off the board.