Accuracy: +/-0.01V; Voltage measuring range: 2.8~25.2V; Function: 1. 3-digit will display in turns at first when power on battery unit 2. LOGO display is completed then display "ALL" indicating next display the total battery voltage of six batteries then displays measured total battery voltage (for example shows "23.2" means that the total voltage is 23.2V). 3. Then display "No1" the following will display a first voltage and then displays the actual measured voltage of the first battery. For example the display "3.12" indicates that the first voltage is measured 3.12V. 4. Next Similarly display "No2" and the corresponding voltage "No3" and the corresponding voltage "No4" and the corresponding voltage "No5" and the corresponding voltage "No6" and the corresponding voltage namely second three four five six battery's voltage. Note: If a section above the voltage shows "ERR" it means that this group of battery voltage is error which may be the root of the tap line is bad or broken or the battery is disconnected