If you could measure the battery during the very first tens of milliseconds of the injection, you would see that the on-load measurement of the voltage would be much lower. However, fully charged worn batteries can give high voltages when measured with no-load. Do never start an acquisition with Tx battery voltage too low (e.g. The voltage can be measured with a voltmeter directly plugged on the two terminals of the battery (no-load measurement). The state of a battery can partially be given by its voltage. The state of the Tx battery used during an acquisition in multi-electrode mode is of paramount importance for the quality of the measurement, and to keep your battery and Syscal in a good shape.

On the importance to use batteries in good state