ECO-WORTHY Cubix100
#1 in Server rackFull review
A low-cost, UL-listed 5 kWh rack module for permitted indoor home backup. Pick a heated or low-temp model if it lives in an unheated space.
Amazon $889.99 ECO-WORTHY $889.99$889.99
The ECO-WORTHY Cubix100 rates 4.7 among server rack 48V solar batterys; the Fortress Power eFlex MAX 5.4 rates 4.2 among wall and floor mount ones. The ECO-WORTHY Cubix100 costs $559.01 less ($889.99 vs $1,449).
Fortress Power eFlex MAX 5.4
A tough 5 kWh module for off-grid cabins, boats and small systems that need an outdoor-rated case. Larger inverters need three or more to run at full power.
Current Connected $1,449$1,449
Prices were last checked October 24, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Scores side by side
These two sit in different case classes (server rack and wall and floor mount), and each is scored against the reference points for its own class, so a rating says how well each does among its own case peers. How we rank explains each factor.
| Factor weight | ECO-WORTHY Cubix100 | Fortress Power eFlex MAX 5.4 |
|---|---|---|
| Overall rating | 4.7/5 | 4.2/5 |
| Value 35% | 95 $174 per rated kWh | 73 $270 per rated kWh |
| Output 15% | 100 100 A continuous (about 5.1 kW) | 39 60 A continuous (about 3.1 kW) |
| Warranty 15% | 100 10-year warranty | 100 10-year warranty |
| Safety listing 15% | 100 UL 1973, UL 9540 listed | 100 UL 1973, UL 9540 listed |
| Cycle life 10% | 60 6,000 cycles at 80% depth, maker rating | 100 8,000 cycles at 80% depth, maker rating |
| Features 10% | 70 inverter communication, app; no self-heating | 70 inverter communication, app; no self-heating |
Specifications
| ECO-WORTHY Cubix100 | Fortress Power eFlex MAX 5.4 | |
|---|---|---|
| Capacity | ||
| Case | Server rack (19-inch) | Wall or floor mount |
| Nominal voltage | 51.2 V | 51.2 V |
| Capacity | 100 Ah | 105 Ah |
| Energy | 5.1 kWh | 5.4 kWh |
| Usable energy | 5.1 kWh | - |
| Chemistry | LiFePO4 | LiFePO4 |
| Cycle life | 6,000 at 80% depth | 8,000 at 80% depth |
| Power | ||
| Continuous discharge | 100 A | 60 A |
| Peak discharge | 120 A | 130 A |
| Max charge current | 100 A | 100 A |
| Modules in parallel | Up to 32 | Up to 16 |
| Safety and communication | ||
| UL 1973 | Yes | Yes |
| UL 9540A | Yes | Yes |
| UL 9540 | Yes | Yes |
| Communication | CAN, RS485, RS232 | CAN, Modbus, Wi-Fi |
| Works with inverters | Victron, Deye, Growatt, Lux Power, Sol-Ark, GoodWe, EG4, SRNE | Fortress Envy, Schneider, Sol-Ark, Midnite Solar, OutBack, Morningstar, Phocos, Victron, Growatt |
| Self-heating | No | No |
| App | Yes | Yes |
| Build | ||
| Display | No | No |
| Built-in breaker | Yes | - |
| Enclosure | - | IP65 |
| Dimensions | 22.09 x 19.02 x 5.63 in | 17.5 x 7.2 x 24.2 in (446 x 184 x 616 mm) |
| Weight | 103 lb | 112 lb |
| Warranty | 10 years | 10 years |
| Released | 2026-03 | 2024-05 |