Grid-Scale Energy Storage

JAM Max

500kWh and beyond. When the scale of the project demands more — more power, more duration, more resilience — the JAM Max is the answer.

Grid-Scale Output LiFePO₄ Chemistry IP55 Rated Bespoke Configuration

Discuss Your Requirements View Specs

500kWh+

Base Capacity

70%

Fuel Saving vs Diesel

4,000+

Charge Cycles

0dB

Silent Operation

250 kW+ Continuous Output

1,228.8V DC Nominal Voltage

IP55 Weather Protection

Unlimited Scalable via Parallel

Bespoke Configuration

The JAM Max isn’t an off-the-shelf product — it’s a power infrastructure solution. We work with your engineering team to specify, configure and deploy a system sized precisely to your project’s load profile and duration.

The Unit

When the project demands grid-scale power

The JAM Max is our flagship containerised BESS — a 20ft shipping container format packed with LiFePO₄ cells, a dual-channel smart BMS, active thermal management, and a full suite of grid-interface electronics. It’s designed to sit at the heart of a site’s power infrastructure, not at the edge of it.

Multiple units can be paralleled to deliver megawatt-hour scale storage. Pair with grid connection, generators, or a solar array. The Max supports islanded, grid-tied and hybrid operating modes — configured by our engineers to match your exact requirements before delivery.

Capability Overview

500kWh

Base unit capacity

Single-unit deployment. Expandable via additional units in parallel with no upper theoretical limit.

250kW

Continuous AC output

Per unit. Stack units to scale output linearly — two Max units deliver 500kW continuous.

3 modes

Operating configurations

Islanded off-grid, grid-tied export/import, and hybrid with generator or solar integration.

>92%

Round-trip efficiency

Measured AC-AC across full charge/discharge cycle. Higher than any diesel-only alternative.

Zero Thermal Runaway

LiFePO₄ at grid scale. The same inherently stable chemistry — no compromise on safety regardless of system size.

Dual-Channel BMS

Redundant battery management across two independent channels. If one path fails, the system continues operating on the other.

Grid Interface Electronics

Full grid-tied capability with power factor correction, reactive power support and frequency response. DNO-ready documentation supplied.

Unlimited Parallel Scaling

No theoretical upper limit on system size. Three units delivers 1.5MWh. Our engineers handle system integration at any scale.

Active Thermal Management

Forced-air and optional liquid cooling maintains cell temperature within ±2°C of optimal across the entire cell array.

Dedicated Project Engineer

Every Max deployment is assigned a named JAM engineer for the duration of the hire. On call 24/7, familiar with your system configuration.

Full Specifications

Capacity (base unit)	500 kWh
Scalability	Unlimited (parallel)
Nominal Voltage	1,228.8V DC
Max Continuous Output	250 kW per unit
Peak Output	300 kW (30 min)
AC Output	125A 3-phase CEE
Grid Connection	415V / 11kV (via tx)
Charge Input	125A 3-ph / Solar MPPT
Operating Modes	Islanded / Grid-tied / Hybrid
Cell Chemistry	LiFePO₄ (LFP)
Cycle Life	4,000+ @ 80% DoD
Round-Trip Efficiency	>92%
BMS	Dual-channel smart BMS
Thermal Management	Active forced-air + optional liquid
Operating Temperature	–20°C to +55°C
IP Rating	IP55
Enclosure Format	20ft container
Dimensions (L×W×H)	6,058 × 2,438 × 2,591 mm
Weight	~8,500 kg
Transport	Flatbed / HIAB / crane lift
Display & Monitoring	SCADA / HMI touchscreen
Connectivity	4G / fibre / SCADA integration
Grid Compliance	G99 / G100 / EREC S34
Compliance	UKCA / CE / IEC 62619
Thermal Runaway Risk	Zero
Noise Output	0 dB (silent)
Support	Dedicated project engineer, 24/7

Discuss Your Project

How It Works

From enquiry to live system

Load Assessment

Share your site load profile, duration and access constraints. Our engineers analyse your requirements and specify the right system configuration.

System Design

We produce a full single-line diagram, protection coordination study and grid connection documentation. Provided at no extra cost on Max hires.

Delivery & Commissioning

HIAB delivery to site. Our engineers commission the system, configure the BMS and SCADA to your parameters, and hand over a fully live system.

Ongoing Support

Your dedicated JAM engineer remains on call for the duration of the hire. Remote monitoring via SCADA with on-site response within 4 hours.

Ideal For

Where the Max is deployed

Major Infrastructure

Motorway schemes, rail upgrades, utility installations and large civil engineering projects requiring reliable megawatt-hour scale power for extended durations.

Large-Scale Events

Major festivals, international sporting events and large public gatherings. Power main stages, arenas and entire site infrastructure without a single diesel generator in earshot.

Grid Resilience

Temporary grid reinforcement during peak demand periods, planned outages or network upgrades. DNO-compliant and grid-interface ready as standard.

Film & TV Production

Powering entire studio complexes, large-scale location shoots and multi-unit productions. When the Pro isn’t enough, the Max handles the full site load.

Emergency & Defence

Field hospital power, disaster response infrastructure and MOD exercise support. Rapid deployment with certified resilience and 24/7 engineer availability.

Remote & Off-Grid Sites

Long-term power for sites without grid access. Pair with solar for a fully renewable off-grid power plant — no fuel logistics, no emissions, no noise.

Product Range

Compare the JAM range

JAM Lite

20 – 50 kWh

Compact and portable. Ideal for smaller sites, short-duration events and locations where access is tight.

View JAM Lite →

Tell us about your project

The Max is specified per project. Get in touch with your load requirements and we’ll come back with a full system proposal — usually within 24 hours.

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