How we score
Every model on this site gets a 0–10 score computed from five official specs — the same formula, the same inputs, for every unit. There is no editorial dial to turn. This page is the whole method.
The formula
Each metric is min-max normalized across the 12 models we track:
(value − min) / (max − min). Weight is inverted, so lighter scores higher.
The score is ten times the weighted sum:
score = 10 × (0.25·capacity + 0.25·AC output + 0.20·cycle life + 0.15·portability + 0.15·solar input)
| Metric | Weight | Direction | Why it matters |
|---|---|---|---|
| Battery capacity (Wh) | 25% | Higher is better | How long it runs your gear. |
| AC output (W) | 25% | Higher is better | What it can power at all. |
| Cycle life (rated cycles) | 20% | Higher is better | How many years before the battery fades. |
| Portability (weight, lbs) | 15% | Lower is better | Whether you'll actually take it along. |
| Max solar input (W) | 15% | Higher is better | How fast it refills off-grid. |
Cycle life is parsed as the leading integer of the manufacturer's rating (e.g. "3,000+ cycles to 80%" → 3000). When a model is missing a metric it scores zero on that term — the formula never guesses.
A worked example
The current top scorer, EcoFlow DELTA Pro 3:
| Metric | Raw value | Normalized | Weight | Points |
|---|---|---|---|---|
| Battery capacity | 4,096 Wh | 1.000 | 25% | 2.50 |
| AC output | 4,000 W | 0.649 | 25% | 1.62 |
| Cycle life | 4,000 cycles to 80% | 1.000 | 20% | 2.00 |
| Portability (weight) | 113.5 lbs | 0.149 | 15% | 0.22 |
| Max solar input | 2,600 W | 1.000 | 15% | 1.50 |
| Total | 7.8 |
Data sources
Every spec comes from the manufacturer's official product page — never from retailer listings, reviews, or forums. Each product page links the exact source its numbers came from, so every figure is one click from verifiable.
Update cadence
Specs are re-verified against the official pages on a monthly cycle, and scores are recomputed the day any data point changes or a model enters or leaves the list. The footer of every page shows the last data update (currently 2026-08-08).
What we don't do
We don't lab-test. We don't tear units down, run load banks, or claim hands-on time. We don't show prices — we have no live price feed yet, so prices and availability are checked on Amazon. And we don't sell placement: no brand can pay to move a score, because the formula only reads specs.
How we make money
As an Amazon Associate we earn from qualifying purchases made through links on this site. Commissions come out of Amazon's pocket, not yours, and they never enter the formula — the math only sees specs. 作为亚马逊联盟成员，我们从合格购买中获得佣金。
Corrections
If a number here ever differs from the official brand page, the official page wins. Verified errors are fixed in the next update cycle. To flag one, email the corrections address published with our newsletter signup (launching soon) — until then, the official sources linked from every product page are the authoritative record.