There is no chargers-per-room ratio, and any source offering one is guessing about your guests. Rooms do not charge — cars do. The count comes from your own busiest nights: how many EV guests arrive wanting a plug, knowing that one overnight bay serves one car per night. Count that, install for it, and prepare the wiring for the next phase.
Key Takeaways
- No chargers-per-room ratio exists — count EV guests who need a plug on your busiest nights.
- One overnight bay serves one car per night; that fact does most of the arithmetic.
- Install for the counted number plus a bay of slack; prepare conduit and capacity for double.
- Re-count from records — full-bay nights, logged waiting, enquiry growth — and let triggers open phase two.
The Four Inputs to Count
| Input | Where you read it | Why it matters |
|---|---|---|
| EV guests on your busiest nights | Front-desk enquiries, booking notes that mention charging, a count of EVs in the car park on full nights | This is the demand the bays must meet — not the room count, not an industry average |
| Share who arrive needing a plug | Ask at check-in for a few weeks; note who actually plugs in | Some EV guests arrive nearly full or charge en route; not every EV in the car park is a session |
| Nights plugged in per stay | Reception observation once chargers exist; before that, your judgement from stay lengths | A three-night guest may plug in once or twice — one bay can serve one long-stay car across several nights |
| Bay turnover | The pattern of your car park | Overnight bays turn once per night; day-use bays near a restaurant or conference space can turn more than once |
A Worked Example, With Invented Inputs
Every figure here is invented to show the method; your inputs will differ. Suppose a 90-room property counts its fullest nights for a month and finds 7 EV guests on the busiest night, of whom about 5 wanted a plug on arrival. Five plugs a night, at one car per bay per night, means 5 working bays — and the property installs 6, holding a bay of slack for a unit out of service. The same count sizes phase two: conduit and capacity are prepared for 12 bays while only 6 are fitted, so growth is a hardware purchase, not a building project. The room count, 90, appears nowhere in the arithmetic — that is the point.
Phase the Build, Then Re-Count
The start-small approach in our hotel EV charging guide works because the second phase is decided by evidence, not forecasts. Set your own triggers in advance and read them from records you already keep:
- Full-bay nights. Sessions or staff notes show every bay taken on a run of busy nights.
- Waiting and complaints. Guests who asked for charging and could not get it — logged at the desk, not remembered anecdotally.
- Enquiry growth. Booking enquiries mentioning charging rising season on season.
The same counting discipline applies beyond hotels — our guide to apartment and condo charging in shared parking counts resident demand the same way, from observed cars rather than formulas.
Hardware That Fits a Phased Count
Phasing is easier when the hardware scales in small steps. The EV-AC03201T dual-connector AC station (two Type 2 connectors, up to 43 kW shared, OCPP 1.6J, RFID, IP54) adds two bays per unit, so a six-bay first phase is three stations on one design; its touchscreen is a display, not a payment terminal. Single bays in scattered spots — a small annexe car park, a row by the entrance — are the EV-ACT3204PE 22 kW wallbox’s job (tethered Type 2 cable, RFID and app, IP66, CE). Both report session records, which are what your re-count reads. The full range is on our commercial EV charging page.
Frequently Asked Questions
Is there a standard ratio, like one charger per 20 rooms?
No standard ratio exists, and one would mislead anyway: a city hotel and a rural touring hotel with the same room count can have very different EV-guest numbers. Your busiest-night count is the only ratio that describes your property.
Should we install for future demand now?
Prepare for it, do not fit it. Conduit, capacity and bay layout for the next phase are cheap during the first build; hardware bought for demand you have not counted is capital sitting idle. Fit for counted demand, wire for growth.
What if two guests want the last bay?
That is a phase-two trigger, not a crisis: log it. Hotels handle the night itself with a waiting order at reception, valet moves where offered, or pointing the second guest to the nearest public charger — and the log entry is what justifies the next phase.
Related Reading
- Hotel EV Charging: How to Plan Guest Charging That Pays Off
- Apartment and Condo EV Charging in Shared Parking
- Workplace EV Charging Program Guide
- Do Hotels Have Charging Stations for Electric Cars?
