How we work

Last updated August 18, 2026

We do not test hardware. We verify numbers. This page explains where every figure on this site comes from and how you can check it yourself.

What we are not

There are people who put chargers in freezers for fourteen hours to measure how stiff the cable gets at −18 °C, and they are better at that than we would be. When you need to know how a unit behaves in the real world, we link to them by name.

What almost nobody maintains is the layer underneath the buying decision: what electricity actually costs on your utility's plans, which incentives still exist, and how many amps your car can genuinely use. That is the part we do.

Electricity rates

AmpLedger currently covers 52 residential rate plans across 25 states. Every one is read from the utility's own filed tariff, rate schedule, or published rate page — never from an aggregator, and never from another website's summary.

Each record carries the source URL, the effective date the utility states, and the date we last verified it. Both dates are shown in the calculator, and the source is one click away.

Full price versus partial price

This distinction matters more than anything else on this site. Some utilities publish a complete delivered price per kilowatt-hour. Many publish only one component — distribution, or base energy before riders — and the number you would naively use is far below what you would actually pay.

Of the plans we carry, 19 publish a full delivered price and 33 publish only part of it. Every partial plan is flagged in the calculator with an explanation of what is missing. We would rather show you an incomplete number honestly labeled than a complete-looking number that is wrong.

Seasons

Most time-of-use plans price summer and winter differently, and some have three seasons. We store each season separately with the number of months it covers, and the annual figures in the calculator are weighted accordingly rather than taken from a single season.

What we will not assert

We do not state which edition of the electrical code applies in your state. Published sources contradict one another and the authoritative body does not maintain a reliable public map. We tell you to confirm with your local authority, because that is the only correct answer.

Vehicle charging rates

Maximum AC charging rates come from manufacturer documentation — press kits, specification PDFs and support pages — not from enthusiast wikis. Where a manufacturer and an aggregator disagree, we follow the manufacturer.

We store amperage rather than kilowatts. Manufacturers mix AC input power with power delivered to the battery, and quoting kilowatts propagates that ambiguity. Amperage is unambiguous, and it is what determines the circuit you need.

Vehicle efficiency figures, used to estimate annual energy, are editorial estimates and are labeled as such wherever they appear. Real efficiency varies with climate, terrain, driving style and tires.

Products

Amperage, connector standard and availability are verified directly on the retailer's product page, not from search results or press coverage. Each product record carries its verification date. Retailers delist products and change specifications constantly, so we re-check rather than assume.

We do not publish prices. Prices change too fast for a static page to be honest about them.

Opinion versus fact

Anything that is our judgment rather than a sourced fact is written as judgment. When we say the market for 32-amp chargers is badly served, that is an opinion formed from the prices we observed, and we show you the prices so you can disagree.

Corrections

If a figure here is wrong, we want to know. Write to hello@ampledger.com with the page and the source that contradicts us. We correct errors rather than quietly editing them away, and material corrections are noted.

Independence

No utility, manufacturer or retailer pays for placement on this site, and none reviews our content before publication. We earn affiliate commission on some product links, which is explained in full in our affiliate disclosure. Recommendations are ordered by what fits your vehicle, never by what pays best.