Expansion Batteries

Expansion Batteries for Longer Backup

Increase the battery capacity of compatible portable power systems for longer home backup, travel and off-grid use.

  • Longer runtime
  • Modular capacity
  • Compatible systems
  • Home and travel
Choose Your Expansion Path

Scale your backup setup the right way

Start with a lighter battery extension for compact systems, step up to a stronger mid-tier option for longer runtime, or build toward a larger high-capacity setup when your backup needs are more demanding.

Unsure which route fits your setup? Use the Power Calculator
Compact Extension

Lighter runtime boost for smaller setups

Best if you want a more compact expansion route for supported systems where portability and simpler runtime extension matter most.

  • Smaller supported systems
  • Portable, easier-to-handle module
  • Ideal for lighter runtime extension

Best fit: B80P

Shop B80P
Best for Most Setups

The strongest all-round step up in runtime

The clearest middle-ground choice for buyers who want a meaningful increase in stored energy without jumping straight to the biggest system tier.

  • More stored energy for longer use
  • Balanced step up in capacity
  • Cleaner route to a more capable setup

Best fit: B210P

Shop B210P
High-Capacity Build

For larger scalable backup systems

Best if you are building toward a more demanding expandable setup and want significantly more stored energy for larger backup requirements.

  • Large expandable backup builds
  • Longer runtime across heavier use
  • Premium step-up in total capacity

Best fit: B500

Explore B500

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Expansion batteries and compatible modules give you a practical way to increase runtime, raise overall system capacity and build a more capable backup setup without replacing your existing power solution.

At VoltReady, this collection is designed for customers who want a more scalable setup for home backup, off-grid use, travel and flexible everyday power where longer runtime and system growth matter most.

These products are ideal for extending supported systems across longer outages, heavier daily use, mobile working, garden offices and wider backup planning, with options ranging from compact battery expansion to larger high-capacity modules for more demanding setups.

If you are planning a wider system, use our UK Power Calculator. You can also browse compatible Portable Power Stations, explore ready-made Portable Power Kits, or add system support with selected Accessories.