A business needs as many chargers as its own busiest-day evidence supports — counted separately for staff cars, fleet and pool vehicles, and customers or visitors, because the three groups park differently and peak at different times. There is no chargers-per-employee ratio worth using. This article gives owners a first estimate they can defend: gather a week of evidence per group, check when the groups overlap, then phase the build so infrastructure goes in ahead of the ports.
Key Takeaways
- Count staff, fleet and customer demand separately — the groups park differently and peak at different times.
- The binding number is EVs present at the busiest hour, not EVs per day or per employee.
- Phase the build: infrastructure for the full plan, ports fitted against counted demand.
- Count connectors, not units, and let session records size every stage after the first.
Count the Three Groups Separately
| Demand group | Evidence to gather | How it turns into ports | The trap |
|---|---|---|---|
| Staff cars | EVs in the staff car park on normal days, plus who is about to buy one | Long, predictable dwell; the count follows daily EVs, not total headcount | Sizing from the staff list instead of the cars that actually arrive |
| Fleet and pool vehicles | Vehicles that must leave charged, and their turnaround windows | Schedules rule: a fixed departure needs its charge guaranteed, so these ports are counted first and shared last | Folding must-be-full vehicles into the general pool and hoping |
| Customers and visitors | EV arrivals on your busiest trading days, and how long they stay | Short dwell means each port serves several cars a day — or queues if the peak is sharp | Averaging across the week and missing the Saturday peak |
For staff programmes — policy, attribution and rollout — our workplace charging program guide goes deeper. A week of honest observation beats any benchmark.
Check the Overlap, Not Just the Totals
Group totals mislead when the peaks coincide. If the peaks are staggered, the same bays can serve two groups across a day. If they land together, the count is set by the combined peak, not by each group’s average. Walk your site at its busiest hour and count EVs present, not EVs per day — that single number disciplines the estimate. Most business dwell suits Level 2 (7–19 kW, U.S. DOT; roughly 10–20 miles of range per hour): the constraint is cars plugged in at once, not the port.
Phase It: Infrastructure First, Ports in Stages
- Size the electrical work for the full plan. Supply, cable routes and bay preparation are cheapest while the ground is open once — and a licensed electrician must confirm capacity in writing, since each circuit is sized at 125% of charger current (NEC continuous-load rule).
- Fit ports for the demand you have counted. Ports are quick to add on prepared routes; idle ports bought early are capital parked in a car park.
- Let session records size the next stage. A term of data — which ports fill, at what hours — replaces opinion when stage two is argued.
Cost scales with the phasing: DOE-cited figures put public Level 2 at about $3,500 equipment plus $2,500 installation per connector, so stage-one infrastructure with fewer ports is a real saving. Our commercial installation cost guide breaks down where that money goes.
Hardware That Fits a Phased Count
Dual-connector hardware suits a phased plan because each unit adds two counted ports: the EVDANCE EV-AC03201T dual-connector AC station provides two Type 2 connectors sharing up to 43 kW (22 kW per connector), with OCPP 1.6J and RFID so sessions are recorded per driver — the records that size your next stage. EVDANCE is a Shenzhen manufacturer founded in 2011, exporting to 30+ countries, with a 3-year standard warranty. See the commercial EV charging range or contact us with your three group counts.
Frequently Asked Questions
Is there a standard ratio of chargers to employees?
No — no regulator or standard publishes one, and any figure quoted without your site’s evidence is a sales rule of thumb. Two businesses with identical headcounts can need very different counts.
Should we install for the EVs we expect in five years?
Build the infrastructure for growth — supply, routes, prepared bays — but fit ports for the demand you have counted now and the near term. Adding ports later on prepared routes is a fitting job; repeating groundworks is a building job.
Do visitors change the count much?
They can, because their peak is sharp and their dwell is short. Count your busiest days separately; a small visitor count at a hard peak can need its own ports even when the weekly total looks trivial.
Related Reading
- How to Plan a Workplace EV Charging Program
- How Much Does It Cost to Install a Commercial EV Charging Station?
- How Do Commercial EV Charging Stations Work?
