CMJ Solar Apollo vs Ares: Which All-in-One ESS Series Is Right for Your Market?

Distributors evaluating an all-in-one ESS line for their market often face a false choice: modular flexibility versus integrated simplicity. CMJ Solar builds both platforms—the Apollo and Ares series—because different customers, housing stock, and grid conditions demand different form factors. Stocking the wrong mix ties up capital in slow-moving SKUs and leaves revenue on the table when a project requires the architecture you do not carry.

Two Platforms, Two Philosophies

The Apollo series is a modular, stackable tower system. Each battery module measures 60×40.5×19.5cm and stacks vertically beneath or beside a shared inverter head. Capacity scales from 5kWh to 30kWh by adding modules, and installers can choose between a 6KW or 12KW inverter depending on the customer's load profile. The architecture is designed for customers who may start small and expand later—a common scenario in markets where rooftop solar is added in phases.

The Ares series takes the opposite approach: a single integrated cabinet that houses the battery, inverter, MPPT controller, and BMS in one enclosure. It is available in 7.5kWh, 10kWh, and 15kWh configurations with inverter outputs from 5KW to 12KW. There are no external module connections to manage, no stacking hardware, and no field-expansion option. Ares ships as a complete, pre-wired unit that an installer can mount and commission in a single visit.

The distinction extends beyond physical form. Apollo's modularity means a distributor can stock a common inverter head and separate battery modules, reducing inventory complexity because one SKU (the 5.12kWh module) serves every capacity point from 5 to 30kWh. Ares requires stocking three distinct finished-goods SKUs, but each unit is ready to ship as a complete system with no assembly or module pairing required.

Apollo A: Modular and Stackable

Apollo A Specifications and Options

The Apollo A line spans six capacity points at 51.2V: 5kWh (100Ah), 10kWh (200Ah), 15kWh (300Ah), 20kWh (400Ah), and 30kWh (600Ah). Each module adds 5.12kWh, and the discharge current scales proportionally—100A for the 5kWh unit, 200A for 10kWh, 300A for 15kWh, and so on. This matters because larger battery banks with higher discharge current can sustain heavier continuous loads without hitting BMS limits.

For the 10kWh and 20kWh capacities, CMJ Solar offers both a standard 6KW inverter variant and a P-suffix 12KW variant. The Apollo A 10kWh with 6KW inverter handles single-MPPT installations with up to 9000W of PV input and a 120A charge current. The Apollo A 12KW 10kWh upgrades to dual MPPT (2×7500W PV) and 160A charge current for roofs with mixed orientations or higher power demands. At the 20kWh tier, the Apollo A 20kWh 6KW provides 20480Wh (400Ah) for customers who need long runtime without the extra inverter headroom.

All Apollo A units operate at 51.2V with a 230V inverter output, an 80–500V PV input range, and LiFePO4 chemistry. The modular design means a customer can purchase a 5kWh system today and add modules as budget allows—an important selling point for installers who want to close the initial sale without pricing the customer out of a full 15kWh system. The vertical tower also minimizes floor footprint: even the 30kWh configuration occupies the same 60×40.5cm base area as the 5kWh unit, growing only in height.

Ares: Integrated Single-Cabinet Simplicity

Ares Specifications and Options

The Ares line offers three models. The Ares 7.5kWh with 5KW inverter is the only unit in the CMJ Solar ESS lineup that operates at 25.6V rather than 51.2V. It delivers 7680Wh (300Ah) through a 5KW inverter with a wide 60–450V MPPT range and a 160A charge current, supporting up to 9000W of PV. The 25.6V platform makes this unit particularly cost-effective for budget-sensitive markets where essential loads are modest.

The Ares 10kWh with 6KW inverter moves to 51.2V with 10240Wh (200Ah), a 5500W PV input, and a 120–500V MPPT range. It is the volume model in the Ares range—compact at 84×48×30cm and straightforward to install. At the top end, the Ares 15kWh with 12KW inverter delivers 15360Wh (300Ah) at 51.2V through a 12KW inverter with dual MPPT (2×7500W PV, 160A charge current). It is a high-power, high-capacity unit in a single 78.2×57×40cm cabinet—no stacking required.

The Ares form factor is especially attractive for new construction and retrofit installations where the homeowner wants a clean, appliance-like appearance. Because all wiring and connections are contained within the cabinet, there are no exposed module-to-module power cables, and the unit can be placed against a wall with minimal clearance. For rental properties and multi-unit developments where installation speed and consistency matter, Ares reduces per-unit labor time compared to assembling a multi-module Apollo tower on site.

Head-to-Head: Apollo vs Ares

When comparing equal capacities, the most direct matchup is the Apollo A 10kWh versus the Ares 10kWh. Both deliver 10240Wh at 51.2V with a 6KW inverter. The Apollo uses a 9000W single MPPT with an 80–500V window, while the Ares uses a 5500W PV input with a 120–500V window. The Apollo can absorb more solar power in a single string and offers field expandability; the Ares arrives as a single cabinet with simpler wiring and lower installation labor. The Apollo is a vertical tower of stacked modules; the Ares is a floor-standing cabinet. The Apollo starts at 5kWh and scales to 30kWh; the Ares maxes at 15kWh.

At the high end, the Ares 15kWh 12KW competes directly with the Apollo A 15kWh—but only the Apollo offers a 12KW inverter at that capacity (via the P-suffix path at 10kWh or 20kWh). The Ares 15kWh includes the 12KW inverter as standard, making it a straightforward pick for customers who want maximum power and capacity in one unit without planning for future expansion.

For the budget entry segment, the Ares 7.5kWh at 25.6V has no direct Apollo equivalent. It is purpose-built for markets where a 51.2V system is overkill, either because the inverter loads are small or because the existing solar infrastructure is 24V-based. This makes Ares the more versatile line for distributors serving diverse regional markets with varying voltage standards.

Matching Series to Customer Profile

Large Homes and European Markets

European customers in Germany, Italy, Spain, and the UK typically demand higher capacity, 51.2V architecture, and the ability to expand as their solar array grows. They often have higher per-capita electricity consumption, larger homes with air conditioning or heat pumps, and favorable net-metering or feed-in policies that make larger batteries financially attractive. For these buyers, the Apollo A series is the stronger fit. Start with a 10kWh or 15kWh unit and add modules as needed. The 12KW P-suffix variants handle heat pump and EV charging loads. The vertical tower form factor suits utility rooms and garages where depth is available but floor footprint must be minimized.

Budget Homes and African Markets

Across much of sub-Saharan Africa, parts of South Asia, and price-sensitive markets in the Middle East, customers prioritize affordability, reliability, and ease of installation over modular expandability. Grid outages are frequent and often prolonged, but the essential-load list is shorter—lights, phone charging, a TV, a fan, and perhaps a fridge. The Ares series aligns well with this profile. The 25.6V Ares 7.5kWh offers a lower entry price point while still delivering 7680Wh and a 5KW inverter. The Ares 10kWh at 51.2V is the step-up for customers who want more runtime. The single-cabinet design reduces installation complexity for local technicians who may have limited training on modular battery systems. For larger homes or small businesses in these markets that do need 12KW and 15kWh, the Ares 15kWh covers that segment without requiring the Apollo's modular architecture.

Distributors should also consider after-sales service models. Apollo's modular design allows individual battery modules to be swapped under warranty without replacing the entire system, reducing field service cost for large deployments. Ares units, while simpler to install, require replacing the whole cabinet if a major component fails. For markets with strong local service networks, Apollo's modular serviceability is an advantage; for markets where customers prefer a simple swap-and-replace warranty, Ares may be more practical.

Common Mistakes When Choosing Between Series

The first mistake is assuming modular is always better. A customer who will never expand beyond 10kWh pays a premium for the Apollo's stacking hardware and module connectors they will never use. The Ares is the more cost-effective choice for a fixed-capacity installation. The second mistake is assuming integrated is always simpler. If a customer buys the Ares 10kWh and later wants 20kWh, they cannot add modules—they must purchase a second complete unit, which costs more than adding two Apollo modules. The third mistake is mismatching the PV input: the Ares 10kWh's 5500W PV limit may bottleneck installers who want to pair it with a 6–8kW array. The Apollo's 9000W PV input offers more headroom. The fourth is ignoring physical dimensions: the Apollo tower grows taller with each added module (each 19.5cm), while the Ares remains a fixed cabinet. Verify ceiling height and wall clearance before specifying either platform.

A fifth mistake is not accounting for shipping and warehousing. Apollo modules are flat and uniform, optimizing container loading and allowing distributors to stock a single module SKU plus inverter heads. Ares cabinets are larger and vary in size across the three models, which can reduce container density and increase per-unit freight cost. For high-volume distributors focused on logistics efficiency, Apollo's modular packaging offers real advantages.

Final Recommendations

Distributors should carry both series to cover the full range of customer profiles, but lead with the platform that matches your primary market. For European, Australian, and high-consumption markets, the Apollo A 10kWh and 12KW variant are the core SKUs, with the 20kWh model for larger homes. For African, South Asian, and budget-focused markets, the Ares 7.5kWh at 25.6V, Ares 10kWh, and Ares 15kWh 12KW cover entry-level through high-power needs. Browse the full CMJ Solar energy storage catalog and contact our team to build a product mix tailored to your region.