Battery Capacity Testing

Uninterruptible power supply (UPS) and DC Power Systems are used to provide emergency power to loads when AC mains power experience sudden interruptions/failures. The equipment to which they are connected may range from computers, servers to control systems critical to the company or plant’s continued operations. How do you know when the UPS will have sufficient reserve battery power to sustain operation until your back up generator kicks in? The printed rating in your battery nameplate may provide the system’s capacity but this is not the true capacity. Over time, the cells in the battery degrade whether they are used or not and lead to loss in capacity.




Routine maintenance procedures like cell or intercell connector voltage and internal resistance measurements can predict some problems but the only way to confirm a battery’s performance is to do a “Capacity testing”, otherwise known as “Load testing”. This is performed by discharging the battery and verifying that the battery voltage will remain above a minimum voltage in the specified period of time. A battery rated 12V/100Ah/C10 must be able to discharge a constant 10A every hour for 10 hours and final terminal voltage must not be lower than 10.8V to be considered 100% capacity.

Capacity testing should be performed on all critical battery applications, as its failure to supply full capacity can lead to unintended disruption to company operations.


Benefits of Battery Capacity Testing:

  1. Maximum reliability of back up power supplies as capacity testing guarantees critical battery performance.
  2. Avoid loss of opportunities and downtime for companies relying on battery power for their operations.
  3. Replace the batteries only when they are less than 80% of their capacity. Extending the use of a viable battery instead of relying on routine replacement schedules can lead to significant savings.


Please contact us to learn more about this.   


Contact Us.