Is your battery bank truly capable of providing the backup you need?

 It’s a simple question but one too many electrical professionals leave unanswered until it’s too late.

When did you last audit your DC battery system?

The battery bank is the last line of defence in any critical electrical system—whether it’s a substation, industrial control system, telecom site, hospital, or process plant. And yet, many are designed on assumptions rather than solid, real-world data. The result? Unreliable backup, accelerated degradation, and systems that may not hold up when you need them most.

Let’s ask some hard questions

• Was the battery sized correctly?
  Was a detailed load profile used, accounting for the actual connected loads and load drop-off logic? Or was it a best guess, recycled from a similar project?
  If your system wasn't built using real-time measured data or an accurate forecast of load demands, there’s a good chance it’s either undersized or overengineered in the wrong areas.

• Were the right design contingencies applied?
  You can’t just look at nominal capacity. Temperature corrections, expected aging over 10–15 years, float charging behaviour, and maximum expected ambient conditions must all be considered.
  Many failures occur not due to battery faults, but due to poor thermal planning or inadequate aging margin.

• Is the battery type fit for purpose?
  It’s not just about lead-acid vs. lithium. It’s about:

  • Maintenance access

  • Ventilation and gassing considerations

  • Frequency of cycling

  • Environment (indoor vs outdoor, hot vs cold, clean vs corrosive)

  • Expected lifespan and serviceability

Too often, battery decisions are based on budget constraints or rough sizing estimates. But the cheapest option upfront often becomes the most expensive mistake down the line especially when critical operations are disrupted due to battery failure or backup insufficiency.

The reality of DC system neglect

At Josty, we regularly conduct audits across a wide range of industries from utilities to infrastructure and industrial applications. One common pattern? The DC system is often overlooked once commissioned. It’s assumed to be “set and forget.” But that’s a dangerous assumption.

We’ve seen sites where:

• Battery banks were still operating years beyond their rated life

• Load profiles had changed dramatically since the original installation

• Autonomy requirements increased but weren’t reassessed

• Ventilation and room conditions had degraded over time

• There was no clear maintenance schedule or test data history

And when problems strike during an outage or load shed it’s always the battery that gets blamed. But the problem almost always starts earlier… in the design, selection, and maintenance of the system.

How Josty can help

We specialise in helping businesses audit and optimise their DC systems and battery backup. Our process includes:

• Reviewing the original design, spec, and as-built installation

• Verifying site conditions, environment, and current load behaviour

• Testing and inspecting the battery health and performance

• Identifying risks, gaps, and opportunities for lifecycle improvement

• Delivering clear, actionable recommendations for compliance and performance

You’ll receive a detailed report tailored to your site’s conditions and business needs whether that’s ensuring redundancy, extending service life, or planning for future load expansions.

Visit Backup Power Solutions for Business | Josty NZ to learn more about our engineering services and battery audits.

Ready to take the guesswork out of your critical backup systems?

👉 Book an audit of your battery bank and DC system today via Contact Josty | Business Consulting NZ or send us a message directly.