Fortress Power eFlex MAX 5.4 vs SunGoldPower SG48100P

Last updated: October 24, 2026

The SunGoldPower SG48100P rates 4.6 among server rack 48V solar batterys; the Fortress Power eFlex MAX 5.4 rates 4.2 among wall and floor mount ones. The SunGoldPower SG48100P costs $359 less ($1,090 vs $1,449).

Fortress Power eFlex MAX 5.4 vs SunGoldPower SG48100P

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 weightSunGoldPower SG48100PFortress Power eFlex MAX 5.4
Overall rating4.6/54.2/5
Value 35%86 $213 per rated kWh73 $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 warranty100 10-year warranty
Safety listing 15%100 UL 1973, UL 9540A listed100 UL 1973, UL 9540 listed
Cycle life 10%80 7,000 cycles at 80% depth, maker rating100 8,000 cycles at 80% depth, maker rating
Features 10%55 inverter communication; no self-heating70 inverter communication, app; no self-heating

Specifications

SunGoldPower SG48100PFortress Power eFlex MAX 5.4
Capacity
CaseServer rack (19-inch)Wall or floor mount
Nominal voltage51.2 V51.2 V
Capacity100 Ah105 Ah
Energy5.1 kWh5.4 kWh
ChemistryLiFePO4LiFePO4
Cycle life7,000 at 80% depth8,000 at 80% depth
Power
Continuous discharge100 A60 A
Peak discharge150 A130 A
Max charge current100 A100 A
Modules in parallelUp to 63Up to 16
Safety and communication
UL 1973YesYes
UL 9540AYesYes
UL 9540NoYes
CommunicationCAN, RS485, RS232CAN, Modbus, Wi-Fi
Works with invertersGrowatt, Deye, SunGoldPower, Luxpower, Victron, Schneider, Phocos, SMKFortress Envy, Schneider, Sol-Ark, Midnite Solar, OutBack, Morningstar, Phocos, Victron, Growatt
Self-heatingNoNo
App-Yes
Build
DisplayYesNo
Built-in breakerYes-
EnclosureIP20IP65
Dimensions19.3 x 18.9 x 5.5 in17.5 x 7.2 x 24.2 in (446 x 184 x 616 mm)
Weight93 lb112 lb
Warranty10 years10 years
Released2023-072024-05

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