72V battery expansion for the Symphony 3kVA online UPS

Designed by Uniti Power for the Symphony SPY3000RMi2U, the EBM7218RT2U is a 72V external battery module that extends how long the 3kVA UPS can support its load during a power cut. Each 2U rack/tower module contains maintenance-free sealed lead-acid batteries. Up to four can be connected, giving a typical 67.4 minutes at the full 3000W load and 155.0 minutes at 1500W.

The SPY3000RMi2U's internal 72V battery string gives a typical 3.5 minutes at full load, enough for short interruptions but not for every continuity plan. IT networks, communications racks and healthcare systems often need to stay online for longer. Adding EBM7218RT2U modules provides that extra autonomy while keeping the same UPS power module, so runtime can be specified to the requirement rather than limited by the internal batteries.

EBM7218RT2U specifications

Runtime with one to four modules

Typical runtimes for the SPY3000RMi2U at half and full load:

Runtimes are typical values for new, fully charged batteries at 25°C, provided as a guide only. Actual runtime depends on battery age, temperature and the type of load.

Mounting and connection

The EBM7218RT2U follows the same rack/tower approach as the UPS it supports. Rack ears and tower feet come with every module, along with the EBM cable used to connect it, and a rail kit is optional. At 600mm deep, check that the cabinet has enough depth before installation. Uniti Power's Symphony Range Brochure describes these external battery packs as hot-swappable.

Battery life is best when the module runs at 20-25°C; operating outside that range may reduce battery life and performance. For help with system design and fitting, see installation and commissioning.

Warranty and support

Each EBM7218RT2U is covered by a 2-year warranty. Full terms are on the warranty information page, and Uniti Power technical support can advise on the right number of modules for a given load.

What's in the box

EBM7218RT2U battery module, EBM cable, rack ears, tower feet and user manual. A rail kit is available as an option.

EBM7218RT2U questions answered

Is the EBM7218RT2U compatible with the Symphony 1.5kVA UPS?
No. The EBM7218RT2U is a 72V module for the Symphony 3kVA SPY3000RMi2U. The 1.5kVA SPY1500RMi2U uses the 36V EBM3618RT2U.

What is the maximum number of EBM7218RT2U modules per UPS?
Four EBM7218RT2U modules can be connected to one SPY3000RMi2U.

What runtime does the SPY3000RMi2U give with two EBM7218RT2U modules?
A typical 31.4 minutes at 3000W and 75.9 minutes at 1500W.

How are the batteries in an EBM7218RT2U replaced?
The EBM7218RT2U uses two URBK2 replacement battery kits. Replacement should be carried out by competent personnel following the user manual.

How do I buy the EBM7218RT2U?
Request a quote on this page, call 0845 561 0560, or find a Uniti Power partner near you.

Specifications are taken from the Symphony External Battery Modules Datasheet (PDF). Runtime figures are taken from the Symphony Range Brochure (V1.2025, PDF).