Proven Under Pressure: Delivering Innovation & the Most Reliable UPS Batteries

APRIL 15, 2025

by J.J. Hocken, Product Manager Batteries & DC Technologies

Today’s lithium-ion and alternative battery systems require attention to detail, repetitive cycling, and an in-depth understanding of management systems that protect the safety and reliability of the system.  

Don’t be fooled by hasty or cursory testing that treats a battery as a commodity and glosses over important aspects of battery testing. 

The battery is a vital part of the UPS system, which is why Mitsubishi Electric has a rigorous approach to UPS battery testing—focusing on safety, reliability, and tuning the battery system for Uninterruptible Power Supply (UPS) applications and service. 

Not all batteries or battery test scripts are created equal! Let’s discuss why. 

The Problem

Forcing today’s high power battery systems through a quick verification and testing process can create critical concerns on site, such as: 

• Long delays if serviceability, startup, commissioning, storage requirements, and other aspects of product review were not considered 
• Serious safety problems, such as thermal runaway propagation or electrical faults 
• Catastrophic downtime  

Rushed product testing cannot verify that the battery can and will respond as specified in catastrophic situations (i.e., when you need it most). The battery supporting the critical operations of your business needs to be thoroughly tested or it will cost you and your customers millions of dollars. 

The Mitsubishi Electric Testing Difference

Mission critical facilities depend on Mitsubishi Electric’s critical power solutions to keep their businesses from going dark. Our 99.9995% uptime and reliability start with extensive research followed by rigorous UPS battery testing.   

The Research

Battery testing at Mitsubishi Electric starts well before we receive battery product samples. We conduct a thorough and detailed information gathering process which includes, but is not limited to: 

• Safety listing and testing documentation review 
• Protection settings and system behavior analysis 
• Preliminary testing data (Cell, Module, Rack, Parallel Rack Level) 
• Up front review of system input/output (I/O) and integration requirements 
• Determination of product strengths and weakness  
• Constructive feedback to vendors to shape how they design a battery, determine its chemistry, and manage it 
• Treating a new DC product like our own; we want to know everything about it   

If the product can’t meet our stringent requirements, Mitsubishi Electric will not test it! 

The Battery Testing

Mitsubishi Electric’s testing and battery verification plan focuses on: 

• UPS system integration, including I/O signals  
• Validation of runtimes 
• Cycling operation characteristics 
• Management system analysis and protection settings 
• System noise immunity 
• Quality and serviceability  
• Measurement accuracies and system behavior 
• Simulation of system failure modes 
• Evaluation of proper load sharing 
• Cycling and charging times 
• Cool down periods and recharge characteristics 
• Transportation and storage requirements 

Other manufacturers approving technologies without following this level of discovery does not influence or change our approval process.

Insights from Our UPS Battery Testing

Our battery testing team’s systematic and detailed test plan has uncovered a variety of areas for concern or improvement, such as:

• Discharge run times do not meet expectations and are not repeatable.
• System management readings are inaccurate or unverifiable.
• Improper or ineffective noise filter on management/monitoring system.
• Charge and discharge characteristics / conditions are erratic or inconsistent.
• Cooldown time periods or immediate recharge requirements and verifications don’t meet specifications.
• Performance in parallel string configurations do not load share correctly.
• Impedance matching is not in specification tolerance for proper load sharing.
• Heat and thermal issues on DC bus connections.
• Erratic heat dissipation between monoblocs and inconsistent heat patterns in cabinets/racks.
• Power connection terminals and sizing do not meet UL/NEC codes.

Building Credibility Through Reliability

While we may not always be the first to launch a product in the industry due to our process, we will always prioritize delivering the most reliable and safe products that meet our customers’ goals. 

The Mitsubishi Electric Approach to testing DC technologies ensures your system – and your business – don’t go dark:

• Detailed root cause analysis and expert troubleshooting results in reduced service time for our customers and lower operational costs.
• Stronger partnerships with battery vendors and suppliers mean our team can provide better customer support and find a resolution more quickly.
• Our DC technology solutions meet UPS industry standards so our customers know their systems can be easily installed, passing all tests for compliance, and are the safest for their application.
• The batteries we accept integrate well with our UPS systems to maintain our high standards for reliability and performance.

Mitsubishi Electric’s Battery Testing Team