Car charging limits: fuses, amps and hours

Two limits, and the lower one wins

Charging from a car outlet runs into two ceilings. The first is the socket's fuse, which EcoFlow says is often 10 A or 15 A. The second is the amp limit the station prints for its own car input. EcoFlow's manuals for the DELTA 3 and the RIVER 2 both print 8 A. On a 15 A socket, the station's own 8 A cap still applies.

Voltage times amps gives the power. At 12 V and 8 A that is 96 W, which matches EcoFlow's own example. EcoFlow says the result is typically capped around 100 to 120 W. It calls car charging better suited to topping off than to a full recharge.

Hours from empty

The car charging checker takes the lower of the outlet fuse and the station's car input amps. It then multiplies by the vehicle's voltage. The times below use that rule at 12 V, at full input and before any losses.

Doubling the battery doubles the time, because the input stays at 96 W. The DELTA 3 Max shows the same 8 A input as the smaller DELTA 3. That is why it takes about twice as long to fill.

The voltage window matters too

Car inputs have a voltage range, and it decides whether a truck with a 24 V system can use one. The RIVER 2 lists 12 to 24 V at 8 A. That would be 192 W at 24 V, and it would bring the 243 Wh battery to full in about 1.3 hours. The Explorer 1000 v2 lists 12 to 16 V, so a 24 V supply is outside what it prints. EcoFlow says a car's system runs from about 12 V to 14.4 V. That sits inside the 16 V ceiling and inside the 24 V ceiling on the RIVER 2.

Some stations print a much wider range. EcoFlow's DELTA 3 Max lists 12 to 48 V on its car input. EcoFlow's DELTA 3 Plus listing prints a separate 800 W car-charging line and names an 800 W alternator charger. A 12 V socket cannot reach that figure, since a 15 A fuse at 12 V is 180 W. The 12 V car input on the same port stays at 8 A in the manual.

Why one station shows two wattages

Car inputs share a port with other inputs on some stations. EcoFlow's DELTA 3 manual lists the car input as 12 V at 8 A on the same XT60i port that takes solar. Jackery's Explorer 300 v2 manual prints 96 W for 11 to 16 V at 6 A. That figure belongs to the 16 V top of the range. At 12 V the same 6 A is 72 W, which is the number used in the hours above. The cable finder lists the car cable each port expects.

Checking your outlet

The fuse rating is printed in the vehicle's owner's manual or on its fuse panel. The checker asks for that figure. A 15 A fuse will not push the DELTA 3 above its own 8 A. A lower fuse, 5 A for example, would hold it to 60 W. The station's manual should carry a car input line with a voltage range and an amp limit. That line is what to compare with the car's system voltage.