Shared EV charging capacity planner
Test whether a shared charging idea is in the right order of magnitude before commissioning a site design. The planner shows how the building power budget and per-port limits constrain daily energy.
How this is calculated
Effective site power is the lower of the building's EV power budget and the total port capacity. Eight 11 kW ports cannot use more than a 44 kW site budget.
Power per port with all ports active divides effective site power equally. A real controller may allocate power differently according to rules, priority or vehicle demand.
Daily energy = effective site power × charging-window hours × utilization. Utilization accounts for unplugged cars, cars that finish early and vehicles drawing below a port's cap.
The session estimate divides daily energy by average energy per vehicle and rounds down. It is an energy-throughput estimate, not a queue simulation.
Assumptions and limits
- This tool is for early planning only. It does not size cables, protective devices, switchgear, transformer capacity, earthing, fire protection or the building connection.
- The site's EV power budget must come from a competent assessment that protects other building loads. Do not treat spare breaker ratings as confirmed continuous capacity.
- Static equal sharing is shown for clarity. Dynamic load management can respond to building demand, but its limits, failure modes and compatible equipment need a designed solution.
- The number of complete sessions does not describe waiting time or fairness. Arrival patterns, dwell time, access policy, billing, reservations and enforcement need separate planning.
Frequently asked questions
Does every shared charger need its full rated power at once?
Not necessarily. A designed load-management system can allocate a site budget across active ports. The service promise and expected dwell time determine whether the resulting speed is acceptable.
How do I estimate utilization?
Use interval data from a similar site if possible. For an early scenario, test several values rather than presenting one guess as a forecast.
Is the result enough for an electrician to install the site?
No. A qualified designer or installer must assess the actual supply, loads, protection, cabling, equipment, local rules and any distribution-network approval.
What else should an apartment or workplace decide?
Decide who may charge, how costs are measured, what happens when demand exceeds capacity, how visitors are handled and who maintains and supports the equipment.
