Why $/Wh Is the Only Honest Metric
Most reviews compare raw prices: "$299 vs $499." That tells you nothing about value. A $299/300Wh station costs the same per watt-hour as a $499/500Wh station. You're comparing price tags, not energy value.
$/Wh = Price ÷ Capacity (Wh)
Lower = better value. Tells you exactly how much you pay per watt-hour of stored energy.
| Station | Price | Capacity | $/Wh |
|---|---|---|---|
| Station A | $149 | 300Wh | $0.50/Wh |
| Station B ✓ | $299 | 1,000Wh | $0.30/Wh — 40% better |
| Station C | $99 | 150Wh | $0.66/Wh |
Station B costs twice as much but delivers 3x the energy at 40% lower cost per Wh. Raw price is misleading. $/Wh is not.
How We Collect Data
Product Discovery
We search Amazon across multiple brand and category keywords to find portable power stations, collecting ASINs, titles, images, and ratings.
Price Tracking
Each product's Amazon page is fetched to get the current price. Every price is stored with a timestamp to build the price history graph.
Specs Extraction
Wh capacity is parsed from titles and verified. We also record output watts, battery chemistry (LiFePO4 vs Li-ion), weight, and warranty.
$/Wh Ranking
Price per Wh is calculated automatically after every price update. Rankings are rebuilt weekly with fresh data.
Update Schedule
- 1Weekly price refreshEvery Monday at 6 AM, we fetch updated Amazon prices for all tracked products.
- 2Price history recordedEach fetch is timestamped and stored, building the price history charts on product pages.
- 3Rankings rebuilt$/Wh is recalculated and all pages are regenerated with current data.
- 4New products addedWe periodically scan for new releases and add them to the database.
What We Track
We track portable power stations sold on Amazon.com with at least 100Wh capacity — devices with a built-in battery, inverter, and multiple output ports (AC, USB, DC). We exclude: standalone solar panels, expansion batteries without inverters, gas generators, and power banks under 100Wh.
FAQ
Are prices always current?
Prices are updated weekly. Amazon prices can change at any time — always verify the current price on Amazon before purchasing. The date of our last update is shown on each product page.
Why do larger stations have lower $/Wh?
The inverter, BMS, and enclosure are fixed costs spread over more energy storage. A 2kWh station will nearly always beat a 300Wh station on $/Wh from the same brand.
Is LiFePO4 worth paying more for?
Usually yes. LiFePO4 lasts 2,000-4,000 cycles vs 300-500 for standard Li-ion. For regular use, LiFePO4 can last 10+ years vs 2-4 years for Li-ion. The lifecycle cost is typically lower.
Do you test products yourself?
We are a price comparison and data site. We do not physically test products. Ratings shown are from verified Amazon purchasers. For hands-on testing, see OutdoorGearLab, Bob Vila, and Tom's Guide.
How do I calculate runtime for my appliance?
Divide station capacity (Wh) by appliance wattage (W), then multiply by 0.85 for efficiency loss. Example: 1,000Wh station ÷ 100W appliance × 0.85 = 8.5 hours of runtime.
Affiliate Disclosure
CheapestWh.com participates in the Amazon Services LLC Associates Program. When you click "Buy on Amazon" and make a purchase, we may earn a small commission at no extra cost to you. This does not affect our rankings — products are ranked purely by $/Wh, not by commission rate or brand relationships.
Contact
Product suggestions, data corrections, or questions: [email protected]
Last updated: April 2026