The current split, in numbers
Start with the specification everything else follows from. Grizzl-E’s spec table for the Duo Connect 40A gives a maximum output current of 40 A and a maximum output power of 10 kW on a 50-amp breaker. Those are figures for the unit, not per connector. The overview page then states the behavior explicitly: dual charging automatically splits the available current in half, or you set individual currents per connector in the app.
Turned into the numbers that matter to a driver, at 240 volts and our standard reference of about 3.5 miles of range per kWh:
- One car plugged in: 40 A, 9.6 kW, about 34 miles of range per hour.
- Two cars plugged in: roughly 20 A each, about 4.8 kW each, about 17 miles per hour each— roughly 34 miles per hour of combined throughput.
- Across a ten-hour night with both plugged in: around 170 miles into each car.
That last figure is the one to sit with. For two commuters, 170 miles of overnight replenishment each is an enormous surplus. For two households sharing one vehicle’s worth of long-distance driving, it may not be. Work out your own numbers with our charging time guide before deciding the split is a compromise.
What you are actually buying: the avoided install
Be clear-eyed about the economics. The Duo costs roughly what two decent single chargers cost, so the hardware is not where you save. The saving is on the other side of the wall:
- One circuit instead of two. One breaker, one run of conductors, one set of terminations. On a long run to a detached garage, the conductor cost alone can be several hundred dollars.
- One load in the panel calculation instead of two.This is the big one. Two 40-amp chargers is 80 amps of continuous load to account for; the Duo is 40. That difference decides whether a service upgrade appears on your quote — see our panel capacity guide.
- One thing to mount, permit and inspect. Simpler job, simpler paperwork, and one inspection.
So the honest framing is not “a dual charger is cheaper than two chargers.” It is “a dual charger lets a two-EV household spend a normal single-charger electrical budget.” If your panel has ample spare capacity and both bays are close to it, two independent chargers may well be the better buy — you get full speed to both cars and independent failure. If the panel is the constraint, the Duo is solving exactly the right problem.
Build and weather
Physically it is a Grizzl-E: an aluminum enclosure with IP67 protection, rated by the company from -30°C to +50°C (-22°F to 122°F), with two 25-foot output cables, an 18-inch input lead and an LED indicator per connector. It weighs about 40 pounds, which is roughly double a single unit and worth knowing before you choose a mounting position — this wants proper structure behind it, not drywall anchors.
Two 25-foot cables from one point is a real planning advantage. Mounted centrally between two bays, each cable only has to reach one car, so you avoid the long diagonal run that makes single-charger two-bay setups awkward. Grizzl-E also builds its cables to stay flexible in cold weather, which matters twice as much when there are two of them to coil. Our placement guide covers how to work out the position before the electrician arrives.
The app, and the per-connector control
Grizzl-E’s overview describes the Duo Connect as a Wi-Fi connected charger shipping with the Grizzl-E Connectapp, with schedules, usage history, remote lockout, monitoring and diagnostics — and, specifically for this model, the ability to set amperages for each connector.
That last capability is more useful than it first appears. An automatic 50/50 split is the sensible default, but real households are not symmetrical: one car may be a long-range EV that needs most of the current and one a plug-in hybrid that cannot use it anyway. Being able to allocate, say, 30 amps to one connector and 10 to the other turns the Duo from a blunt splitter into something closer to a small load-management system. If your two vehicles have very different appetites — see our PHEV guide— that alone can remove the speed objection entirely.
The connector caveat, said clearly
The Amazon SKU we track for the Duo Connect 40A is the NACS-to-NACS variant — two Tesla-style plugs. Grizzl-E lists the Duo Connect with J1772 and NACS cable options, so other pairings exist, but the cables are not user-swappable and you are committing to a connector layout for the life of the unit.
For a two-Tesla household that is ideal, and removes two adapters from your life at once. For a mixed fleet, check the exact listing before ordering, and consider whether a J1772 pairing plus the Tesla’s own bundled adapter is the more flexible arrangement — it covers every car either way. Our connector guide lays out the whole picture.
What Grizzl-E does not publish
Two gaps worth stating rather than glossing. Grizzl-E’s spec table for the Duo Connect 40A does not publish a warranty termfor this model, so our spec table records “Not published” — ask the seller before you buy, because Grizzl-E does publish warranty terms for other models in its range. And it does not state an ENERGY STARcertification for this unit, which matters only if you are chasing a rebate that requires one; check the exact model against the program’s qualifying list, and see our ENERGY STAR roundup for units where the manufacturer publishes it.
Who should buy it — and who should skip it
Buy it if you have two NACS vehicles, a panel with room for exactly one 40-amp charger, and no appetite for moving a cable every night. It is the cleanest solution to that specific problem: one permit, one circuit, one box, two cars, and a build tough enough to sit outside in a real winter. Buy it too if your two cars have different charging appetites, because per-connector allocation makes the split work in your favor rather than against it.
Skip itif both cars regularly need most of a night’s charging — then you need two real circuits, and the roundup at best chargers for two cars covers the load-shared alternatives. Skip it if your vehicles use different connectors and this SKU does not match them. Skip it if your panel has plenty of headroom and both bays are close by, where two Grizzl-E Smart units would give full speed to each car for similar money. And skip it if you have not yet tried the free option: for a great many two-EV households, one charger and a cable moved twice a week is genuinely enough.