How many EV chargers can your site actually support?

Start with maximum demand, not fuse size

Your incoming fuse or agreed capacity is a ceiling. What matters is how close your existing operation already runs to it. A site with a 200 amp supply that peaks at 180 amps has very little room, while an identical supply peaking at 90 amps has a great deal.

Twelve months of half-hourly data, or a temporary logger on a non-half-hourly supply, gives you that peak reliably. Nameplate ratings of your equipment will not.

The arithmetic of a socket

A 7kW single-phase charger draws around 32 amps. A 22kW three-phase unit draws about 32 amps per phase. A 50kW DC unit needs roughly 75 amps across three phases, and a 150kW rapid considerably more.

Multiply by the number of sockets you want charging simultaneously and the constraint becomes obvious quickly. Eight 7kW sockets is over 250 amps of potential demand on top of whatever the building already does.

Load management changes the number

Dynamic load management monitors the incoming supply in real time and shares whatever headroom exists between active chargers. Workplace parking is the ideal case: a car parked for eight hours does not need full power for all of them, so twelve sockets sharing the capacity of four will still return every driver a full battery.

This is the single highest-value item in most workplace charging designs, and it is why unmanaged installations tend to under-deliver sockets while over-spending on infrastructure.

When you genuinely need more capacity

Fleet depots turning vehicles between shifts, and public rapid hubs, do need real power rather than shared power. There the options are a DNO supply upgrade, on-site battery storage buffering the peak, or a phased rollout that grows with the fleet. Price all three; a supply upgrade is not automatically the right first move.