How to measure power supply voltage and battery voltagewith CB86-PLUS charger when you have no multi-meter?The voltage of CB86-PLUS charger needs to be re-calibrated afterupgrading the firmware from Version 2.4 to Version 2.5 and above. If youdon't have a multi-meter, you can measure the power supply voltage andbattery voltage with CB86-PLUS charger under the condition that thecurrent voltage display of CB86-PLUS is correct. The steps are asfollows:1. Before upgrading the firmware, plug the battery into the rightmostinterface of port 1. Wait for 30 seconds and then check the voltage ofeach cell in port 1. Record the voltage value on the second row of the firstbox, as shown in the picture below. The battery voltage can be recordedas 4.200V in the picture (make sure that the cell voltage is between3.8-4.4V). The power supply voltage can be recorded as 12.003V, shownin the upper left corner of the charger screen.