Originally Posted by DaleDe
How old is this unit? Generally it needs to be run down a time or two to calibrate the gauge. It may be that you will not have any further problem once it knows where zero is.
Actually, I would have hoped that the detection of a battery too low to allow turn on would be independent of the battery gauge. The electronics in the reader will have an absolute minimum voltage specification, and protection against operation below that voltage should against a known voltage reference (not some vague 'calibration' against a partially charged battery). It's an easy, simple, and cheap electronic circuit.