Rich Solar ALPHA 5 PRO
5120 Wh, 5120 W
Fortress Power eFlex MAX 5.4
Home battery · eFlex MAX. Specs from the manufacturer page (checked ).
The Fortress Power eFlex MAX 5.4 is a 5.374 kWh LiFePO4 lithium battery with a 51.2 V nominal voltage and 105 Ah nominal capacity. Its recommended continuous discharge rate is 3 kW DC, with a maximum surge of 6.6 kW for 5 seconds. The page lists 8,000 cycles at 80% depth of discharge and a 10-year warranty.
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Capacity
5374Wh
Continuous
3000W
Peak / surge
6600W
Chemistry
LiFePO4
Cycles
8000
Expandable
Yes
Weight
51kg
Warranty
10yr
Key features
- Rated capacity 5.374 kWh at 0.5C (50 A); nominal 51.2 V, 105 Ah
- Recommended continuous discharge 60 A (3 kW DC); peak continuous 100 A (5 kW for 60 min); maximum surge 130 A (6.6 kW for 5 s)
- Up to 16 modules in parallel (86.4 kWh)
- Enclosure rated IP65 dust- and water-resistant; discharge temperature -20°C to 55°C
- Mounting options: wall mount, floor stand, or 19-inch industrial server rack mount
- BMS with high-amperage contactor disconnection and individual cell voltage and temperature monitoring and balancing
- Communication via CAN bus, Modbus, and Wi-Fi; closed-loop communication with most 48 V inverters
- Charge: recommended current under 55 A, maximum 100 A; recommended charge voltage 55.2 V
Specifications
| Capacity | 5374 Wh |
|---|---|
| Continuous output | 3000 W |
| Peak / surge | 6600 W |
| Expandable | Yes |
| Battery chemistry | LiFePO4 |
| Cycle life | 8000 cycles |
| Weight | 51 kg (112.4 lb) |
| Dimensions | 44.6 × 18.4 × 61.6 cm (17.6 × 7.2 × 24.3 in) |
| Warranty | 10 years |
From the Fortress Power page. Values the manufacturer does not publish are left out.
What is in the box
- Terminal cover, 1 set, waterproof
How long it runs common appliances
| Appliance | Watts | Runs? | Hours |
|---|---|---|---|
| Refrigerator (with freezer) | 120 W (600 start) | yes | 4.2 days |
| Chest freezer | 100 W (500 start) | yes | 5.9 days |
| CPAP (no humidifier) | 35 W (40 start) | yes | 5.1 days |
| Gas boiler (pump + controls) | 120 W (300 start) | yes | 71 h |
| Wi-Fi router + modem/ONU | 12 W | yes | 14.8 days |
| Starlink (standard dish) | 60 W (100 start) | yes | 71 h |
| TV 50" | 75 W | yes | 57 h |
| Sump pump 1/2 HP | 920 W (2150 start) | yes | 4.6 h |
| Well pump 1/2 HP | 880 W (2000 start) | yes | 4.8 h |
| Space heater 1500 W | 1500 W | yes | 4.1 h |
Assumes 88 % inverter efficiency, 90 % usable capacity and typical duty cycles. Build your own list in the calculator.
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Connection and wiring
Follow the diagrams in the Fortress Power manual. Connecting to a home panel needs a transfer switch or interlock and a licensed electrician.
Open the Fortress Power manual (PDF) →
Error codes and troubleshooting
| Code | Meaning | What to do | Manual page |
|---|---|---|---|
| Battery Deeply Discharged | The battery has been discharged too far to operate normally. | Isolate the affected battery from the system. Measure voltage from the negative booster port to the positive terminal. Once confirmed, connect a 48V 5A DC max charger to the negative booster port and positive terminal and begin charging. Once 48V is reached, proceed with commissioning. | 30 |
| Communication Error | Communication between the batteries or between the battery and the inverter is not established. | Make sure all batteries are connected to each other, following the Uplink-to-Downlink sequence. Make sure the battery-to-inverter communication cable is connected. Allow about 1 minute for communication to be established between the inverter and battery. | 30 |
| Potential Over Current Discharge | Battery discharge current may be too high. | Power off the batteries starting with the last battery and working toward the first. Press and hold the Power Button until the power-down sequence starts. Leave battery DC breakers on, including the hybrid inverter battery breaker, and leave everything else off. Then power on the first battery, the one whose communication cable connects directly to the inverter battery comms (Closed Loop). | 30 |
From the Fortress Power manual. All 3 eFlex MAX 5.4 codes →
FAQ
How long will the Fortress Power eFlex MAX 5.4 run a refrigerator?
About 101 hours for a typical 120 W refrigerator that runs 35 % of the time, after inverter and depth-of-discharge losses.
Can the Fortress Power eFlex MAX 5.4 start a sump pump or well pump?
Starting surge matters more than running watts: this unit is rated 6600 W peak. That covers a typical 1/2 HP sump pump (about 2150 W to start). Use the calculator with your exact pump.