Two EVs at Home: One Charger or Two?

Most households don’t need two wall chargers. The right setup depends on five things: daily miles for each car, how much evening time overlaps, spare panel capacity, whether you use time-of-use pricing or solar, and how much cable swapping you can accept.

Decision Checklist
Score each item 0–2 (0 = low pressure, 2 = high). Add them up.

Result guide:
0–3 one Level 2 with rotation; 4–6 dual-port or load-sharing on one circuit; 7–10 two dedicated Level 2 circuits.

Quick Math
• Energy needed (kWh) ≈ daily miles × 0.30
• Charge time (hours) ≈ energy needed ÷ 7.2 kW (typical 40 A @ 240 V L2)

Examples
• 35 mi/day → ~10.5 kWh → ~1.5 h. Two cars can rotate easily overnight.
• 70 mi/day → ~21 kWh → ~3 h. Two cars may benefit from dual-port/load-sharing or two circuits to finish within a short off-peak window.

Charging Options for Two EVs

A) One Level 2, rotate by schedule
When it fits: moderate miles, staggered arrivals, or anyone okay moving a plug once.
Pros: low cost; often no panel upgrade; simple to maintain.
Trade-offs: needs a routine; late arrivals may wake up partially charged.

B) Dual-port or load-sharing on one circuit
When it fits: limited panel capacity; both cars home at night; you want automation.
Behavior: two connectors share one feeder; current splits between cars while both are charging; when one tapers or finishes, the other ramps up.
Pros: set-and-forget; often avoids panel work.
Trade-offs: peak rate per car is lower when both charge.

C) Two dedicated Level 2 circuits
When it fits: high miles on both cars; tight morning deadlines; short off-peak windows.
Pros: fastest and most independent; easier to expand later.
Trade-offs: highest install cost; possible panel upgrade.

 Option Comparison

Cost and Install Factors

Electrical Capacity and Circuits
Spare capacity is how much continuous current your panel can safely add. Many homes can support one 40 A circuit for a Level 2 unit without upgrades. A second circuit may require a load calculation and, in some homes, a panel or service upgrade. Load-sharing products let two connectors live on one feeder and coordinate current as cars start and stop.

Single-Phase Reality
You don’t need three-phase to charge two cars. On single-phase, sharing splits available power; the right metric is whether each car reaches its target by departure time, not its peak kW at any instant.

When Two Chargers Make Sense
• Both cars often exceed about 50–60 miles per day.
• Evenings overlap and both must finish before early departures.
• Off-peak tariff windows are short and you want two cars to complete within them.
• Winter range loss or frequent road trips compress your overnight buffer.
• You plan for growth: another EV, visitors, or faster onboard chargers.

When One Charger Is Enough
• Typical days are under 40 miles per car.
• Arrivals are staggered; one car sits most nights.
• You can rotate once in the evening or a few times per week.
• A 120 V cord covers occasional top-ups.
• You prefer to defer panel upgrades.

Implementation Options
• Dual-port EVSE on one circuit: two connectors, coordinated split, simple user experience.
• Two same-brand units with cloud load-sharing: devices balance current on the same feeder.
• Two independent circuits: clean performance for high-mileage pairs or tight schedules.
Tip for flexible nights: in rotation scenarios, a Workersbee portable EV charger helps with temporary or overflow charging without changing fixed wiring.

TOU and Solar: Finish Both in the Cheap Window
• Start both sessions near the off-peak opening.
• Prioritize the early-departure car with a higher target or earlier start.
• Expect slower rates while both are charging; once the first tapers or completes, the second ramps.
• With rooftop solar, combine daytime charging for one car and overnight for the other to improve self-consumption.
For fixed installations that see daily use, durable Workersbee EV connectors pair well with scheduled charging and load-sharing strategies.

Safety, Permits, and Installation
• Confirm permit and inspection needs before work.
• Match conductor size and breaker rating; respect continuous-load limits.
• Use weather-appropriate enclosures and fittings outdoors; add drip loops.
• Keep cables off walkways; add hooks or rests; avoid tight bends.
• Label circuits and parking spots so rotation stays simple and safe.

FAQ
Can two EVs share one charger effectively?
Yes, if miles are moderate or you can schedule. Load-sharing or dual-port hardware reduces hassle.

Do I need three-phase to charge two cars at once?
No. Single-phase can support two cars with sharing or two circuits. Peak speed per car is lower than a single dedicated circuit.

Is a second charger worth it with TOU or solar?
If your cheap window is short or you aim to maximize self-consumption, two connectors help both cars finish on time.

Panel capacity seems tight—what is the first step?
Get an on-site load calculation and route assessment, then weigh sharing on one feeder versus a service upgrade.