How we pick

Renter Volt currently covers 14 products across 44 guides. Every one of them was selected and ranked by the process below, which is written down here so you can disagree with it specifically rather than in general.

1. How a product gets onto the site at all

Four filters, applied in this order. Failing any one is disqualifying.

1. 1It must be renter-installable. It goes into service with a plug: no electrician, no permit, no hardwiring, no landlord construction. This single rule excludes most of what competing apartment-charging guides recommend, and it is enforced in the data model — a product cannot be added to this site without asserting it, and the build fails if the assertion is missing.
2. 2It must be currently sold at a retailer we can link to. A recommendation you cannot act on is not a recommendation.
3. 3It must carry a relevant safety listing — UL, ETL or cETLus — for the standard that applies to its category. UL 2594 and UL 2231 for charging equipment; UL 2251 or UL 2252 for couplers and adapters; UL 60730-1 for the switching devices.
4. 4Its specifications must be published by the manufacturer. A product whose figures we cannot source does not ship, and where a specific figure is missing we write that it is not published rather than estimating it.

2. What we evaluate, precisely

• Rated voltage and maximum current, and whether the current is adjustable.
• Maximum power output in kW, and how it relates to the circuit it will actually sit on.
• Cable length — the specification renters underestimate most.
• Plug configuration (the NEMA type) and connector type (J1772 or NACS).
• Enclosure and ingress rating, mated as well as unmated where the manufacturer publishes both.
• Published operating temperature range, and its absence when it is absent.
• Safety certifications, with the certificate number where one is published.
• Computed charge rate and computed running cost, from the formulas below.

3. What we explicitly do not do

• No hands-on testing, of any product, at any time.
• No durability, thermal-cycling or longevity testing.
• No teardowns and no measurement of anything.
• No claim of ownership, installation or day-to-day use of the hardware.
• No first-party review data, and therefore no star ratings and no aggregate rating anywhere on the site or in its structured data.

Where genuine hands-on experience is required and we lack it, the honest move is to cite somebody who has it — an owner report or a manufacturer’s own warning, attributed — rather than implying we found it out ourselves.

4. The arithmetic, shown

Everything numerical on this site comes from four formulas. They are printed here so you can re-run any claim we make with your own numbers.

Continuous current a circuit supports

breaker rating × 0.8 — the continuous-load rule in the National Electrical Code, which caps any load running three hours or more at 80% of the circuit rating. Overnight charging is continuous by any definition. This is where every 12A, 24A and 40A figure on the site comes from.

Charging power

min(circuit continuous amps, charger max, car onboard max) × volts ÷ 1000 = kW — the smallest of the three wins, every time. It is why buying a bigger charger for a smaller circuit changes nothing.

Range added per hour

kW × your car’s miles per kWh — which is why we publish ranges rather than single figures. Real efficiency moves substantially with temperature and driving style.

Cost per mile

your all-in rate ($/kWh) ÷ your miles per kWh — worked through in full on cost to charge, including charging losses and a like-for-like gasoline comparison.

5. How the ranking is decided

There is no score, and that is deliberate: a numeric score implies a measurement we did not take. Ranking is an editorial judgment made against how many renters a product will genuinely work for, weighted in this order:

1. 1Fit to the reader's likely circuit. Adjustable amperage beats peak rating, because a fixed 40A unit cannot use a 30A dryer circuit at all.
2. 2Cable length, because it is the specification that most often turns a correct purchase into an unusable one.
3. 3Published safety listing, and whether the certificate number is stated.
4. 4Enclosure and temperature ratings, weighted heavily for anything that lives outdoors.
5. 5Everything else — scheduling, app control, connector options — which is real but secondary.

Commission rate is not on that list and never enters it. Where Amazon is cheaper than a direct retailer that would pay us more, the Amazon link is the primary button.

6. How prices work

• Every price on this site is pulled live from the retailer, and stamped with the date it was checked.
• Prices older than 48 hours disappear automatically rather than going stale on the page. The button falls back to 'Check price on Amazon', which is honest and is exactly what the link does.
• No price is ever typed into body copy, remembered between builds or carried forward.
• Structured data never carries a price we did not fetch live — the Offer node is omitted entirely rather than filled with a guess.

7. How often this is reviewed

• Daily: live price refresh, automated. It deliberately does not touch any page's last-reviewed date, because a site that claims every page changed every day teaches Google to ignore the field.
• Monthly: every linked product checked for availability; dead picks replaced.
• Quarterly: full re-review of every roundup — specifications re-checked against current manufacturer documentation, ranking re-justified, last-reviewed date updated for real.
• Quarterly: vehicle and connector compatibility re-checked against manufacturer sources, because NACS adoption is actively changing and an undated compatibility claim rots silently.

Every page carries a visible “last reviewed” date, which is a different fact from the price timestamp. Conflating the two is how a site ends up claiming freshness it does not have.

8. How to challenge a recommendation

Tell us it is wrong. If a figure here disagrees with the manufacturer, the manufacturer is right and we want to know — the contact form has a “correction” option and it goes straight to a person. What happens next is in the editorial policy.