I'm having this strange problem with my old T610.
While the phone is off, When i plug in the charger the "charging battery" indicator and the "Red light" on joystick appear, but within few milliseconds the display goes off (red light remains on) and the charging process restarts. This happens continuously until I unplug the charger.
When the charger is plugged while the phone is turned on "Optimized charging" message appears but the "charging indicator" stays on current battery level.
Why is this?