A development gets one connection, sized years before anybody plugs anything in. Brim models the site’s electrical tree — incomer to panel to charger — and shares what each level can carry between the cars actually drawing from it. The number of chargers stops being a question about the substation. On a new build it is also how a site brings more chargers under Part S’s £3,600 average.
Plug five cars into a feeder that can carry three at full rate and something has to give. The drawing below is that feeder. Add cars and watch the allocation move: every charger gets a fair share of what its panel can carry, and the panel gets a fair share of what the incomer can.
Why it exists
A connection is sized for a moment that never comes
Without load management, a supply has to be specified as though everything on it draws its maximum at the same time. Six 32A chargers is a 192A design, and six cars charging flat out at the same moment is not something a residential development does — but the connection is bought for it, and paid for at the substation.
That assumption is what decides how many chargers a site can have. Load management removes it: what the supply can carry is shared between the cars actually drawing from it, so what gets designed for is the demand rather than the worst case.
What the system does
Recalculated every time a car changes what it draws
Shared, not queued
Every car charging on a panel is offered the same amps. When a fourth arrives on a panel already at its limit, the other three come down to make room, and none of them is switched off to do it.
Down fast, up gently
A reduction lands in a single cycle, because nothing should wait to get back under a breaker. Increases are ramped instead, so a car climbs to its share rather than stepping onto it.
Nothing sent unproved
Every cycle adds up what each charger has been given and checks it against every limit above it. If a leg would go over, the cycle is abandoned rather than dispatched.
What it buys
The connection stops setting the ceiling
Fewer substations
A connection is sized on peak demand. Cut the peak and the substation gets smaller, or comes off the drawing entirely.
Headroom to grow
Power the chargers are not taking stays with the development, for the plots and the plant that come later.
Groundworks sooner
No grid reinforcement to apply for, so the programme is not sitting behind a DNO queue it cannot shorten.
The objection every operator raises. The short answer is that overnight the site is empty of demand and full of cars, and a car that arrives at six with half a battery is full well before seven the next morning at a fraction of its peak rate.
The obvious question
Does it slow charging down?
When a board is at its limit, yes, and by less than it sounds. Every car that is charging keeps a floor: the system slows a car down, it does not drop it to nothing. A busy site charges everybody rather than charging a few quickly and leaving the rest with a dead charger and no explanation.
Most of the time there is nothing to share out. Sharing only starts once more cars are drawing than the board they sit on can serve at full rate. Below that every car is offered everything its charger can give it, and a resident would not know the system was there.