The universal charger implements the possibility to calibrate the voltage and ampere readings with a few common components (a charged battery and a tester). The reasons for the implementation of this new features are the following:

• The management of LiPo and SLA batteries needs a more accurate voltage reading in order to meet the stringent requirements in fact of maximum voltage and cutoff.
• Avoid the need of the PC for the Universal Charger usage: the Advanced Charger needs to change some parameters in the source code and to recompile the program for calibration. The Universal Charger performs the same operation quickly and easily with only the charger and a tester.

The voltage calibration is performed using a charged (charged and with stable voltage) battery, and a tester capable to read the voltage of the battery. With more accurate tester the resulting calibration will be more accurate. To perform the voltage calibration use the following steps:

• Connect the battery to the charger
• Connect the tester to the battery to read the voltage (see figure)
• Wait for a stable reading on the tester
• Select "Volt Calibration" on the charger
• If the charger reading is below the tester reading, press the "+ or UP" key on the charger and hold it pressed until the two readings are equal.
• If the charger reading is above the tester reading, press the "- or DOWN" key on the charger and hold it pressed until the two readings are equal.
• At the end press "OK" on the charger and disconnect the battery and the tester.

The current calibration is performed using the charger and a tester capable to read a current of at least 2 Ampere. With more accurate tester the resulting calibration will be more accurate. To perform the current calibration use the following steps:

• Connect the tester to the charger using the "ampere" input (see figure)
• At this point the tester reads a 0.00 Ampere current
• Select "Ampere Calibration" on the charger
• At this point the charger will source a 2.00 Ampere current into the tester.
• If the charger reading is below the tester reading, press the "+ or UP" key on the charger and hold it pressed until the two readings are equal.
• If the charger reading is above the tester reading, press the "- or DOWN" key on the charger and hold it pressed until the two readings are equal.
• At the end press "OK" on the charger and disconnect the tester.