Camera unjustly says battery is low (red flashing led) at power up

Camera takes good pictures but since the start it complaints about 'low batt'.
I.e. at power up or taking a picture the red led flashes and the camera turns off.

Re-inserting the same batteries helps sometimes, but since the cover is not very robust, don't do that too often!

I notices that the rejected batteries still work fine in my electrical shaver. (I.e. it run at the same pace as with fully loaded batteries.)

My experience is that cleaning the contacts of the battery cover and inside the camera helps much better, at least for a longer while.
(on holiday I used a small dot of tooth paste on a cotton swab since tooth paste contains a polisher)

With just 2.4 Volts and high current consumption a bad contact can cause a relative high voltage drop. Apparently the power detection circuit is very picky about any voltage drops due to bad contacts. I hoped a firmware upgrade would help, but also CX6330 version 106 gave no improvement..

My best advice: Use a Q-tip with some contact spray and clean all contacts, incl. those of the batteries themselves.