How we rank products

Every ranking on this site is calculated, not hand-picked. Here is the whole method.

1. Specs come from the manufacturer

We enter only figures the manufacturer publishes and link the page we used under every product. If a figure isn't published we show "Not listed" instead of guessing.

2. Each spec is scaled from 0 to 1

Each criterion has a fixed reference range, from a "weakest reasonable" value to a "best in class" value (for example 250 Wh to 1,000 Wh of capacity for small stations). A product's figure is placed on that range and clamped between 0 and 1, so scores stay meaningful as products are added. For specs where lower is better, such as weight or noise, the range runs the other way. Yes/no features count as 1 or 0. The ranges are listed below.

3. Weights decide what matters most

Each category lists its criteria and weights on the page. The score is the weighted average, multiplied by 10:

score = 10 × Σ(weight × scaled value) ÷ Σ(weight)

4. Missing data is neutral

If a spec isn't published, the product gets the category median for that criterion, so it is neither rewarded nor punished. A few criteria that only apply to some products (like a cycle rating or surge figure some makers don't publish) are skipped instead, and their weight is removed for that product.

5. Prices and ratings switch on automatically

When our retailer feeds supply a current price or customer rating for at least 60% of products in a category, two more criteria join the formula: Price / value (20%) and Customer rating (15%, discounted when there are few reviews). Until then we show "Check price" and never estimate a price.

6. What the score can't tell you

Specs don't capture real-world inverter efficiency, fan noise under load, app quality or long-term reliability. Use the score to shortlist, then read the pros, cons and sources. When we add hands-on testing notes, we label them clearly.

7. Money never changes the order

We earn affiliate commissions from some retailers. Commission rates are not an input to the formula, and no brand can pay for placement. See our affiliate disclosure.

Criteria by category

Small Portable Power Stations (under 700 Wh)

Battery capacity: 25% · range 200 → 700 Wh
Continuous AC output: 20% · range 300 → 1000 W
Max solar input: 15% · range 100 → 300 W
Weight: 15% · range 7.5 → 3.5 kg
Max AC charging power: 10% · range 300 → 700 W
Rated cycle life: 10% · range 2500 → 6000 cycles · skipped when not published
Surge / peak output: 5% · range 600 → 2000 W · skipped when not published

Mid-Size Power Stations (700–1,500 Wh)

Battery capacity: 25% · range 700 → 1300 Wh
Continuous AC output: 20% · range 800 → 2200 W
Max solar input: 15% · range 200 → 800 W
Weight: 15% · range 16.5 → 8 kg
Max AC charging power: 10% · range 900 → 1600 W
Rated cycle life: 10% · range 2500 → 6000 cycles · skipped when not published
Surge / peak output: 5% · range 1600 → 4400 W · skipped when not published

Large Power Stations (1,500–3,000 Wh)

Battery capacity: 25% · range 1500 → 2600 Wh
Continuous AC output: 20% · range 1800 → 3000 W
Max solar input: 15% · range 400 → 1200 W
Weight: 15% · range 32 → 14 kg
Max AC charging power: 10% · range 1000 → 2400 W
Rated cycle life: 10% · range 2500 → 6000 cycles · skipped when not published
Surge / peak output: 5% · range 3600 → 6000 W · skipped when not published

Home Backup Power Stations (3 kWh+)

Battery capacity: 25% · range 3000 → 6200 Wh
Continuous AC output: 20% · range 3000 → 7200 W
Max solar input: 15% · range 1000 → 5600 W
Weight: 10% · range 90 → 25 kg
Max AC charging power: 5% · range 1500 → 3000 W
240 V output (listed): 10% · yes/no · skipped when not published
Rated cycle life: 10% · range 2500 → 6000 cycles · skipped when not published
Surge / peak output: 5% · range 6000 → 14400 W · skipped when not published

Portable Solar Panels

Rated power: 30% · range 40 → 400 W
Watts per kg: 30% · range 10 → 45 W/kg
Cell efficiency (listed): 20% · range 22 → 25 % · skipped when not published
IP68 rated (listed): 10% · yes/no
Bifacial (listed): 10% · yes/no

Expansion Batteries

Capacity: 45% · range 500 → 5100 Wh
Energy per kg: 35% · range 85 → 140 Wh/kg
Cycle rating: 20% · range 2500 → 6000 cycles · skipped when not published