Home / Methodology The Serious Score A product's Serious Score is a 0–100 number built from ten weighted categories. It is published, the math is identical across every product, and it lets one device rank differently for camping, home backup, RV and solar use.
Scoring model Usable battery capacity 15%
Inverter performance 15%
Price-to-capacity value 15%
Recharge performance 10%
Battery longevity 10%
Portability 10%
Solar capability 10%
Warranty and support 5%
Ports and usability 5%
Expandability and features 5%
How each category is scored Capacity : usable Wh (after depth-of-discharge and inverter efficiency), normalized 256–4096 Wh.Inverter : continuous AC output in watts, normalized 200–3600 W.Price-to-capacity value : $ / usable Wh, lower is better (best ~$0.50, worst ~$2.50).Recharge : wall-recharge hours, 0.8 h = best / 10 h = worst.Longevity : rated charge cycles, 500–6000.Portability : inverse of weight, 8 lb–100 lb.Solar : max solar input in watts, 0–1200.Warranty : years, 1–6.Ports : total AC + USB-C + USB-A outlets, 2–12.Expandability : binary — expandable batteries supported = 100, otherwise 40.Use-case scores The same underlying numbers are re-weighted for each use case so a 70 lb system can score poorly for camping and brilliantly for home backup.
Home Backup Capacity, inverter output, expandability, battery longevity and warranty.
Camping Portability, capacity, charge speed, ports and solar — favoring lighter systems.
RV Travel Capacity, inverter, solar input, expandability and portability.
Solar Use Solar input, capacity, charge speed and portability.
Price & value labels Excellent price — excellent Fair price — fair Wait for a sale — wait Overpriced — overpriced Clearance value — clearance Price not verified — unknown