Scoring Methodology

Every product in the AGB database earns a 0–100 overall score and a 0–5 star rating derived from the same reproducible formula. No opinion, no weighting-by-sponsor — the score is a function of the data.

The 45 features

We track 45 technical features across six categories: battery (capacity, chemistry, cycle life, expandability), AC power (continuous output, surge, pure-sine quality, outlet count), charging (solar input, AC recharge time, fast-charge, pass-through, bidirectional), physical (weight, size, noise), connectivity (WiFi, Bluetooth, app control), and advanced features (UPS mode, parallel expansion, EV charge support).

Per-feature scoring

Each feature is scored on a 0–100 scale within its own axis. Numeric specs (capacity in Wh, output in watts) are normalized against the full product range, clipped to realistic use-case thresholds. Categorical features (chemistry type, UPS presence) map to a finite set of scores calibrated against market expectations.

Feature weights

Not all features matter equally. Battery capacity, AC continuous output, and solar-input speed carry the highest weights; surface niceties (LED color temperature, carry-handle count) carry near-zero weight. Full weight table is maintained in our open scoring config and re-derived quarterly against real user behavior.

Overall score → star rating

A product's overall score is the weighted sum of its per-feature scores, clipped to [0, 100]. For compatibility with review-snippet conventions, we also emit a 0–5 star rating: rating = round(score / 20, 1). An overall score of 84 becomes a 4.2-star rating; a score of 72 becomes a 3.6.

Activity scores

The 20 use-case activity scores use the same features but reweight them per-activity. For camping we boost solar input and weight; for home backup we boost AC output and capacity; for CPAP we boost quiet-mode performance and UPS switch-over time. A product can rank #4 overall but #1 for CPAP if its feature mix happens to match that activity's weighting.

Data sources

  • Specifications: manufacturer product pages and spec sheets, re-verified on each price refresh.
  • Prices: Amazon (US & DE), Walmart, and brand-direct pages, refreshed on a recurring schedule.
  • Marketplace availability: live retailer APIs where available; manual confirmation otherwise.

What scores don't measure

Build quality, firmware stability, warranty responsiveness, and real-world battery degradation over 2–3 years are difficult to quantify from spec sheets alone. Our scores reflect the product as shipped; our editorial verdicts (where present) layer in reliability observations from user reports and our own long-term testing.

Conflicts of interest

We participate in affiliate programs (see disclosure). Commission rates vary by retailer and product; they have no input into our scoring formula or ranking output. Our scoring pipeline does not receive retailer or commission data.