Anticipating how your facility’s backup power needs will evolve over time is extremely difficult. As operational demands grow and new equipment is introduced, the expectations for your battery backup system will likely increase as well.
To prevent the expense of having to purchase a completely new system down the line, two questions are frequently asked:
“Is it normal for generator runtime to degrade over time?”
and
“Can I add more batteries to my battery backup system?”
The straightforward answer to both is: Yes.
Let’s break this down in more detail below.
Does System Runtime Decline with Age?
Just like all rechargeable batteries, the ones in your backup system experience gradual capacity loss each time they’re fully charged and then discharged. This deterioration happens because of unavoidable chemical changes inside the batteries—even with excellent maintenance.

To ensure your system continues to deliver the runtime it was designed for, we recommend replacing the batteries every four years.
Regular upkeep is essential to prolong battery life and performance. We advise conducting routine tests—both weekly and monthly—to discharge the batteries partially and to detect any faults early. This practice helps maintain the system’s efficiency and health.
Adding More Batteries to an Indoor Backup System
EverSafe systems follow a modular design approach that prioritizes expandability. Thanks to their vertically-stacked cabinet structure, you can simply attach additional cabinets to the existing unit and integrate more batteries and wiring to extend runtime.

Planning Ahead
Because your requirements may evolve, it’s best to mention your potential need for expansion when placing your initial order. EverSafe can then supply a cabinet equipped with extra empty slots—making future battery additions quick and hassle-free.
EverSafe’s Retrofit Kit
If you didn’t include expansion provisions in your original order, retrofitting is still possible, though a bit more involved. Cabinets already affixed to a wall might need to be temporarily removed to accommodate the retrofit components.
EverSafe’s Retrofit Kit includes everything required to expand your system:
- Additional cabinets
- More batteries
- All necessary hardware and cabling
How to Order an EverSafe Retrofit Kit
The fastest path to expanding your system is to reach out to EverSafe directly.
Contact our product specialists, engineers, or sales team for:
- Quotes on retrofit kits or new systems
- Assistance in integrating alarm systems or other accessories
Phone: 1.800.765.3237
Hours: Monday–Friday, 8:30 am – 5:00 pm EST