Frequently asked questions

Where do the products and prices come from?

Product details, Amazon links, offer availability, and prices come from the official Amazon Creators API. This site does not scrape Amazon product pages. Catalog fields can be incomplete, so an unknown specification is shown as a dash rather than guessed.

How often are prices updated?

Each published, unique product becomes due for a price check every four hours. The scheduled worker runs every five minutes and refreshes up to two Amazon API batches per run. Product specifications are captured during import or a manual refresh, not by the scheduled worker.

What does price per 1,000 mAh mean?

It is the current price divided by the advertised capacity in thousands of milliamp-hours. A $30 power bank rated at 20,000 mAh costs $1.50 per 1,000 mAh. Lower values indicate more advertised capacity for the price.

Is advertised capacity the same as usable capacity?

No. The table compares stated battery capacity on a consistent basis. It does not claim that every model delivers its full advertised mAh at a device's charging voltage, and it does not replace independent laboratory testing.

Why is a price or specification blank?

A price is hidden when Amazon does not return an eligible current offer or when the last successful update is beyond the safety window. Other blanks mean the field was not found with enough confidence in the available catalog data.

How are duplicate products handled?

Results are grouped using ASIN families and normalized brand, model, and capacity data. Only one canonical listing is published for color variants and duplicate bundles. Non-canonical and rejected rows remain outside the public ranking and are not refreshed by the scheduled updater.

What does airline friendly mean?

The filter uses the product's confirmed watt-hour rating, or a clearly marked estimate when only mAh is available. In the United States, the FAA limits ordinary lithium-ion spare batteries and power banks to 100 Wh and requires them in carry-on baggage. Always check the battery label, airline, and destination rules before travel. FAA PackSafe guidance.

Does Amazon influence the ranking?

No paid placement is added to the table. Amazon affiliate links may earn this site a commission after a qualifying purchase, but the default order is calculated from current price and advertised capacity.