In off-grid construction sites, temporary power projects, and microgrid deployments, choosing the wrong hybrid energy series is often more costly than choosing the wrong power rating.
Across Australia, the Middle East, and other remote or fuel-sensitive regions, we are frequently asked the same question:
“P150 and M150 have the same number — what’s the real difference?”
The answer is not found in a specification table.
It lies in how your loads actually behave on site.
This guide is written from real project experience to help you quickly determine:
● When to choose the P Series (High-Power)
● When the M Series (Long-Duration) is the better fit
Executive Summary (For Busy Engineers)
● P Series is designed for high peak power and surge loads
● M Series is designed for long-duration, stable power supply
If your generator sizing is driven by short, high-current start-ups, choose P Series.
If your priority is reducing generator runtime, fuel consumption, and maintenance, choose M Series.
What Is the P Series (High-Power Series)?
The P Series is a high-power hybrid energy storage system engineered to handle demanding, transient loads commonly found on construction and industrial sites.
Its key strengths include:
● Very high peak power output
● Optimised inverter and battery discharge capability
● Control logic designed specifically for surge-heavy applications
Typical Applications
The P Series is best suited for sites with:
● Tower cranes
● Hoists and lifting equipment
● Pumps and compressors
● Electric motors with frequent start/stop cycles
● Multiple machines starting simultaneously
These load profiles are common across construction projects in Australia and large-scale infrastructure and hotel developments throughout the Middle East.
Core Objective of the P Series
● Absorb peak demand with battery power
● Avoid oversizing diesel generators purely for starting current
● Enable effective peak shaving
In many real-world projects, the P Series allows contractors to replace large gensets that would otherwise run inefficiently at low average load.
Typical Models
P150 / P300 / P500 / P600
What Is the M Series (Long-Duration Series)?
The M Series follows a fundamentally different design philosophy.
Rather than maximising instantaneous power, it prioritises:
● Larger energy capacity
● Longer standalone runtime
● Highly efficient coordination with diesel generators
Typical Applications
The M Series is ideal for:
● Site offices and administration buildings
● Worker accommodation camps
● Lighting, communications, and security systems
● Stable auxiliary loads requiring 24/7 operation
These scenarios are especially common in remote Australian sites and Middle Eastern projects where fuel logistics and noise restrictions are major concerns.
Core Objective of the M Series
● Reduce generator operating hours
● Lower fuel consumption and servicing frequency
● Enable valley filling and energy shifting
For steady loads, the M Series often delivers a lower total cost of ownership than simply deploying a larger generator.
Typical Models
M60 / M100 / M150 / M300 / M600 / M900
P150 vs M150: Same Number, Very Different Outcomes
Using P150 and M150 as an example:
Comparison Aspect | P150 | M150 |
Design Focus | Peak power | Runtime & energy |
Battery Capacity | Medium | Larger |
Best For | Surge-heavy loads | Stable, continuous loads |
Primary Value | Replace oversized gensets | Reduce genset runtime |
Although the model number is the same, the problems they solve are entirely different.
A Simple 3-Question Selection Method
In practice, we rely on three key questions to guide system selection:
1️⃣ Does your maximum load occur only for short periods?
● Yes → P Series
● No → Proceed to the next question
2️⃣ Is your generator sized mainly to avoid voltage drop during equipment start-up?
● Yes → P Series
● No → Proceed to the next question
3️⃣ Is fuel cost and generator runtime your primary operational concern?
● Yes → M Series
Final Thoughts: You Are Choosing an Energy Strategy, Not Just Equipment
In hybrid power systems, capacity alone is never the answer — load behaviour is.
There is no universally “better” choice between the P Series and M Series. The right solution depends on:
● Your site’s load characteristics
● Your operational priorities
● Your fuel, noise, and maintenance constraints
If you are uncertain which series best suits your project, the most effective next step is not adding capacity —
it is understanding your load profile first.
📩 For application-specific advice or detailed case studies, contact the Foxtheon technical team.