Sizing calculator

How much backup power do you need?

Choose your devices, a backup window, and what you are planning for. Advanced electrical controls are optional.

POWER NEEDS

Example planning values — edit them to match your actual devices.

DEVICE 1
Source: U.S. Department of Energy appliance tableUses a 50% cycling duty-cycle planning assumption. The 1,500 W startup value is a conservative 3× allowance, not a universal appliance specification. Verify the nameplate or manufacturer documentation.
DEVICE 3
Source: ENERGY STAR certified light-fixture listingExample certified LED fixture value; edit this to match the wattage printed on each lamp.
DEVICE 4
Source: Apple 20W USB-C Power Adapter specificationsUses a maximum adapter output as a conservative planning value; actual charging draw usually varies over the charge cycle.
LOAD SUMMARY
Devices selected
5
Estimated energy
1,215 Wh
After conversion losses
1,430 Wh
Recommended rated capacity
~1,683 Wh+
Maximum simultaneous load
549 W
Startup / surge requirement
1,549 W

Energy uses each row’s runtime, quantity, and duty cycle. Output sums checked devices; unchecked devices are treated as one-at-a-time loads. Startup replaces that device’s running draw during its start event.

YOUR ESTIMATED NEED
Battery size
~1.7 kWh+
Power output
~549 W+
Startup capability
~1,549 W
See calculation details
Device energy
1,215 Wh
After 85% conversion efficiency
1,430 Wh
After separate 15% reserve
1,683 Wh
RECOMMENDED MATCHES
How scoring works
1
Anker SOLIX C2000 Gen 2
2,048 Wh · 2,400 W · 41.7 lb
Match Score 86 / 100
Why this matches
  • Meets your 549 W continuous running requirement.
  • Battery capacity is closely sized to your requested runtime.
  • Its surge rating covers your estimated 1,549 W startup requirement.
  • Includes UPS support for backup-power use.

Trade-off: It weighs 41.7 lb, so lighter eligible options may be easier to move.

Score breakdown
Capacity Fit 98Output Fit 66Use-case Fit 100Portability 47Feature Fit 81
View product details
Check price at manufacturer · Anker SOLIX USExact product listing at Anker SOLIX US — availability may change
Check Price on Amazon.comExact product listing at Amazon US — availability may change
2
Jackery HomePower 2000 Plus v2
2,048 Wh · 2,400 W · 41.45 lb
Match Score 85 / 100
Why this matches
  • Meets your 549 W continuous running requirement.
  • Battery capacity is closely sized to your requested runtime.
  • Its surge rating covers your estimated 1,549 W startup requirement.
  • Includes UPS support for backup-power use.

Trade-off: It weighs 41.45 lb, so lighter eligible options may be easier to move.

Score breakdown
Capacity Fit 98Output Fit 66Use-case Fit 100Portability 47Feature Fit 79
View product details
Check price at manufacturer · Jackery USExact product listing at Jackery US — availability may change
Check Price on Amazon.comExact product listing at Amazon US — availability may change
3
Anker SOLIX S2000
2,010 Wh · 1,500 W · 35.7 lb
Match Score 84 / 100
Why this matches
  • Meets your 549 W continuous running requirement.
  • Battery capacity is closely sized to your requested runtime.
  • Its surge rating covers your estimated 1,549 W startup requirement.
  • Includes UPS support for backup-power use.

Trade-off: Its battery capacity cannot be expanded later.

Score breakdown
Capacity Fit 98Output Fit 83Use-case Fit 71Portability 59Feature Fit 81
View product details
Check price at manufacturer · Anker SOLIX USExact product listing at Anker SOLIX US — availability may change
Check Price on Amazon.comExact product listing at Amazon US — availability may change
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