Simple.

Some current measurements are not very accurate so it's very easy to round up or down to the nearest amp. So to get 3.8KW the Volt might simply be drawing (an indicated) >~15.5A at 240V and rounding up.

Also 3.3KW will happen if you are connected to a public EVSE that is running at 208V (A common three phase voltage found at most commercial locations).

My understanding is the Gen II Volt charger can draw up to a maximum of 16A. The actual power you get will depend on the voltage. The 3.6KW number is just a nominal number.

One of these days I should borrow a digital power analyzer from work and actually record the charge current and voltage.

 

SEE- that is why they called the car a VOLT

now why don't we get a VOLT meter in the car ;-)

and as he said (without the PF and RMS ) Voltage is NOTconstant but the power company is very good about 60 HZ

 

I don't have a gen 2, but I think the OBCM charges the battery at 3.6KW, and the input from the utility power is 3.8KW to account for the charger losses. The OBCM limits the Input current to 16A, AND, must obey the EVSE "pilot" signal on the J1772 plug. 16*240 = 3.8KW
With 208VAC input, the OBCM still observes the 16A limit, and can only can get 16*208 = 3.3KW, and 3.1KW into the battery.

The gen 2 OBCM is about 94% efficient, the gen 1 somewhat less at 89-90% (IIRC).
Neglecting battery cooling losses, if required.

 

I see. The current is limited... I should say, actively adjusted to 16A. "Actively" because it cannot be done with just a resistor.
So what rate do you guys with Gen 1 see at the chargers' displays?

 

3.6kW is the max the onboard charger can pull. That rating is done at 250VAC, and is standard across EVs. Even my Model S' onboard charger is rated at 10kW, but that's 40A @ 250VAC. Luckily, the voltage to my house is upwards of 248VAC, at times.

So, if you have something that can pull a maximum of 3600W @ 250VAC, you're looking at 14.4A. The more realistic wattage is going to be 3,456W if you take the 14.4A @ 240VAC.

As others have said, those stations probably do not take into account for voltage fluctuations when they calculate wattage. I've seen public L2 charging stations range from 197VAC to 247VAC. The AMPS they provide is fixed in the pilot signal, which is usually the safe maximum that the copper can handle. Back in 2013, taking long distance trips in the Tesla was a bit of adventure when coming across a 208VAC @ 24A unit. Soooooooo sloooooowwwww.....

 

If the real limit for the gen2 (2016-2018) charger is 16A, then if your house has 240V then wouldn't that come out to 3.8 kW? (And if your has 250V then it would be 4.0 kW.) If so, why do they call it a 3.6 kW charger (up from 3.3 kW in gen1)?

 

The gen2 Volt charging at 240v is usually 15amps, or 3.60kw, but if the car needs to turn on the TPMS to cool/heat the battery than the power drawn increases to 240v 16amps or 3.84kw. So it switches back and forth between 3.60kw and 3.84 kw as needed. In mild weather, TPMS is not required so the Volt is charging only at 3.60kw. On very hot days in the summer in Texas the AC can run continuously for TPMS and the gen2 Volt is charging at 16amps, 3.84kw.

The gen2 Volt charging using 3 phase electricity is at 208v 16Amps; 3.32kw. Public chargers often use 3-phase electricity.

For comparison, the gen1 Volt was limited to 13.75amps at 240v or 3.30kw, and 15amps at 208v or 3.12kw.