Last updated: May 2026 · Verified against manufacturer specs · Download CSV
How to Evaluate
The 6 Specs That Matter
Capacity (Wh)Fuel tank. 1000Wh ÷ 100W device = ~10hrs (×0.85 real world)Inverter (W)Running = continuous. Surge = motor startup (0.2s)ChemistryLiFePO4 = 3000+ cycles, 10yr. Li-ion = 500 cycles, lighterUPS Switchover<10ms = NAS/PC safe. <30ms = most electronics OK. None = not a UPSSolar Input110-300W typical. Check max VOC voltage matches your panelsPure Sine WaveMandatory for NAS/CPAP/laptops. Modified sine damages gear
Price Benchmarks & Use Cases
$1.00/WhStandard (e.g. $500 for 500Wh)$0.67/WhGood value (e.g. $199 for 299Wh)$/WhExcellent (e.g. $1000 for 2000Wh)
Use cases: Camping: 300-500Wh. Van life: 700-1000Wh. Home backup: 2000Wh+. NAS UPS: 300Wh+, <10ms, pure sine.
⚠ Pure Sine Wave is NOT optional. If a unit doesn't explicitly state "pure sine wave", don't buy it. Modified sine wave causes buzzing, overheating, and can permanently damage NAS, CPAP, and laptops.
Reality Check: Are the Claims Legit?
Weight Analysis (Wh/kg)
All models verified against official specs. System-level energy density for LiFePO4:
Premium (90+): EcoFlow Delta 2 Max (89.1), RIVER 2 Pro (98.4)
Normal (70-90): OUKITEL P800E (85.3), ALLPOWERS R600 (85.6)
Conservative (50-70): EcoFlow RIVER 2 (73.3), RIVER 3 Plus (60.9), Bluetti EB3A (58.5)
Ref: Tesla Powerwall = 118 Wh/kg. Bluetti AC200P = 73 Wh/kg. Red flag: >120 Wh/kg at system level = fake capacity.
Capacity Claims
All manufacturers quote cell-level rated capacity. Usable output is ~80-85% due to inverter losses. A "512Wh" station delivers ~410-435Wh to devices. This is normal industry-wide, not a scam.
✓ All listed models pass the weight/capacity sanity check.
Verified <10ms UPS
Independently tested or confirmed by official spec sheets:
ALLPOWERS R600 — tested by BatterySkills
EcoFlow RIVER 3 Plus — official spec
OUKITEL P800E — official spec
Bluetti Elite 30 V2 — official spec
Anker Solix C300 — official spec
Anker Solix C1000 Gen2 — official spec
ALLWEI 1200W — official spec
Most others: 20-30ms (not NAS-safe) or no UPS at all.
💡 Gimmicks assessment: LED lights are genuinely useful for camping/emergencies. Wireless charging is convenient but slow (15W). App control is nice for monitoring. LCD screens are essential. Don't pay a big premium for extras — focus on the 6 core specs.
NAS UPS Compatibility
A NAS (Synology/QNAP) draws 20-60W (2-bay) or 40-100W (4-bay). For safe UPS operation:
Switchover must be <10ms — 30ms crashes NAS and corrupts data
Pure sine wave required — NAS PSUs are sensitive to dirty power
Pass-through charging — unit stays plugged in, battery on standby
USB signaling — some units support USB to NAS for auto-shutdown
Runtime: 300Wh × 0.85 ÷ 30W NAS = ~8.5 hours of backup
"9 times out of 10, the answer is no. Many power bank manufacturers advertise UPS backup but have auto-switchover times of 30 milliseconds or more." — EcoFlow official blog
"Its 10ms UPS switchover was genuinely instantaneous, preventing our work-from-home setup from even blinking." — BatterySkills, ALLPOWERS R600 review
"EcoFlow RIVER 3 Plus is an affordable NAS-compliant UPS with a switchover time of less than 10 milliseconds." — EcoFlow official
Comparison Table
Click any column header to sort. Click again to reverse. All specs verified against manufacturer data sheets.
All four have verified <10ms switchover. ALLPOWERS has the best warranty (6yr). OUKITEL has the most capacity per dollar. ALLWEI gives you 1kWh+ in NAS UPS mode.
⛺ Camping / Portable
1st:OUKITEL P800E — 512Wh, 800W, 13.2 lbs, $179
2nd:EcoFlow RIVER 2 — 256Wh, 7.7 lbs, proven brand
3rd:Bluetti EB3A — 268Wh, 10.1 lbs, 2500+ reviews
🏡 Home Backup
1st:EcoFlow Delta 2 Max — 2048Wh, 2400W, 1000W solar