How to size chargers to your vehicles' dwell time
The right charger power comes from how long a vehicle sits, not its battery size. Long dwell means slow and cheap is plenty.
Last updated 15 August 2026
The single most useful number when choosing chargers isn’t the vehicle’s battery size or the charger’s headline speed — it’s dwell time, the hours a vehicle sits parked and available to charge.
Work backwards from the parked window
If you know how much energy a vehicle needs (its daily distance times its efficiency) and how long it’s parked, the charger size falls out: energy needed, divided by hours available. A vehicle back at 5pm and out at 6am has thirteen hours to refill — so even a modest charger delivers far more than it needs. There’s simply no benefit paying for speed you can’t use.
Long dwell rewards patience
Because most depot vehicles rest overnight, long dwell is the norm, and it’s a gift: it lets you specify slower, cheaper AC chargers and share them across vehicles under smart charging. The money you’d have spent on rapid chargers stays in your pocket, and your grid draw stays low.
Short dwell is where you pay for speed
Only when the parked window is genuinely short — a vehicle on a quick turnaround between shifts — do you need faster, more powerful chargers. Identify those cases specifically rather than assuming the whole fleet needs speed. Usually it’s a minority.
Sizing to dwell time is also what reveals you need fewer chargers than vehicles: several vehicles resting overnight can share a charger by taking turns. Map your real dwell times first, and the hardware specification almost writes itself.