Maintenance and Calibration


The following maintenance suggestions for neware battery testing systems are listed.

  • To achieve the best performance and testing accuracy, the battery testing system should be calibrated annually.
  • The surrounding space must be clean, with proper temperature and humidity levels to avoid influence on the equipment accuracy, damage to the inner circuit or even safety issues.
  • Also do not storage battery testing system in a space with large temperature differences, as this will cause inner circuit corrosion.
  • Do not use any chemical detergent to clean the inside of the battery testing system. Some unknown chemicals may corrode inner components.
  • Use battery testing system and accessories from Neware only.
  • Always backup your important data to avoid unexpected errors or failures.

Proper use and maintenance of the battery testing system will help you get the best performance. Our data from many years of investigation and after sales service indicates that battery testing system failures usually were the result of improper use or lack of maintenance. If you are experiencing any issues of our equipment, please do not hesitate to contact us.

Calibration and Its Methodology

Calibration may be required:

  • After battery testing system has been repaired or modified.
  • When a specified time period has elapsed.
  • When a specified usage (operating hours) has elapsed.
  • Before and/or after a critical battery testing activity.
  • After an event, for example
    1. After the battery testing system has had a shock, vibration, or has been exposed to an adverse condition which potentially may have put it out of calibration or damage it.
    2. Sudden changes in weather.
    3. Improper use of software to cause the loss of the calibration data.
  • Whenever observations appear questionable or battery testing system indications do not match the output of surrogate instruments.
  • As specified by a requirement, e.g., customer specification.


Calibration, in general use, is often regarded as including the process of adjusting or aligning the output of or indication on the equipment to agree with value of the applied standard, within a specified accuracy.

Neware battery testing system generally outputs and measures current and voltage. And it has different circuits for charge and discharge. So we need to calibrate a). Charge Current; b). Discharge Current; c). Charge Voltage; d). Discharge Voltage.

  • Charge Current / Discharge Current (If negative power supply installed)

Since standard current meters generally cannot support large current, a DC shunt should be introduced for large current calibration. The current value given by the battery testing system should be compared to the measured current through the shunt.

current calibration connection diagram

Figure 78 : Current Calibration Connection Diagram

  • Discharge Current (No negative power supply installed)

If there is no negative power supply installed, the battery testing system cannot discharge unless you connect a battery which functions as a power supply and the battery testing system functions as a load. You can calibrate discharge current at this situation just string a battery in the circuit as above diagram in Charge Current / Discharge Current (If negative power supply installed) section .  You need to consider the discharge capability of the battery connected.

  • Charge Voltage

Now string a resistor in the circuit as below diagram, set constant voltage charge, this will create a voltage at the ends of the resistor. Neware battery testing system will read a voltage value, the external meter will also read a voltage value.  These values will be used for the calibration.

voltage calibration connection diagram

Figure 79 : Voltage Calibration Connection Diagram

  • Discharge Voltage

For the equipment with negative power supply and empowered with Constant Voltage Discharge, you can use the same logic as above or calibration of the charge voltage. If this is not possible, a digital voltage signal source needs to be introduced for the calibration.

Manual Calibration

  • This calibration tool is an old version. Our latest BTS Client now has integrated calibration function. They have similar usage. Since NwCal.exe is largely used before. Below steps indicate how to calibrate neware battery testing sytem using this software.
  • NwCal uses RS232 or RS485 to communicate. So before you conduct the calibration work, you need to release the connection from bottom machine to middle machine, connect an RS232 cable directly from the middle machine to the host computer. If the RS232/RS485 port on the battery tester is 9-pin male port, use a 9-pin RS232/RS485 wire to connect computer to the computer’s COM port. If the RS232 / RS485 on the battery tester is RJ45 jack, use an adapter wire – one end is RJ45 and the other is COM port, or use an RJ45 straight through cable to black Port Adapter(if purchased) which uses USB or COM port to be connected with the computer.
  • Since models of different current ranges have different default segments for the calibration, you need to match the calibration segment ranges to the correct the battery tester you are going to calibrate. If your model has a current lower than or equal to 6A, use 1 segment. Use 3 segments if the current range larger than 6A. Voltage and current will have the same number of segments.

calibration segments settings

Figure 80 : Calibration Segments Settings

  • Click OK and exit the program. After you connect the bottom machine to the host computer with RS232 cable, you can re-launch this program. The program will search for the units automatically. Click Yes to load the calibration data for the connected unit.

load calibration data

Figure 81 : Load Calibration Data

  • In the right area, there are channels listed, type of accuracy test and calibration mode for your choice, and if this unit is a main channel, there will be 4 items needed to calibrate – CC (Charge Current), CV (Charge Voltage), DV (Discharge Voltage) and DC (Discharge Current). If you are calibrating current and the circuit uses a shunt, you need to select Shunt choice from the Digital Multi-Meter field, and input an accurate value for resistance.

calibration overview

Figure 82 : Calibration Overview

  • Clicking Run will measure the battery testing system response to the calibration. You will also obtain a value from the meter you connected – current or voltage based on the item you selected and the circuit you connected. If you choose current calibration and your circuit has a shunt, you can only input the voltage readings into the Meter Value box– the program will calculate the equivalent current based on the voltage and the resistance.
  • Now Click Run again, program will measure the battery testing system response at another point of the segment. Input the meter value as performed in the above procedure. If all points for this item of the channel have been finished, the program will jump to the next channel for calibration. Now you can move onto next item like CC (Charge Current).
  • If you do not have battery testing system powered with negative power supply and no available battery function as an external power source, you may choose Copy KB Value on the right click menu after you have finished CC (Charge Current) calibration. Similarly, when you do not have a digital voltage signal source, you may choose Copy KB Value after you have finished CV (Charge Voltage) calibration.

copy kb value

Figure 83 : Copy KB Value

When all items of all channels have been calibrated, you now click Write KB(W) to save all the calibration data. Restart to enable changes.

Auto Calibration

Our automated calibration system is an auxiliary piece of neware battery testing system hardware integrated with all the necessary parts mentioned above as well as software with all calibration related functions.

diagram of auto calibration system for neware battery testing system

Figure 84 : Auto Calibration System Diagram


auto calibration processing

Figure 85 : Auto Calibration Processing


You can choose to generate calibration reports after the completion of the calibration for neware battery testing system.

calibration report

Figure 86 : Calibration Report