You have a Gen 2 Volt, which is capable of drawing a max of 3.6kW (assuming input is at 240V/15A)
If it is drawing lower than that, the factors could be
a) Amperage (somehow, your EVSE is limiting to lower amperage)
b) Voltage (I have seen 208, 220 and 240 in US)
c) Battery level: Volt starts tapering charge rate down as the battery starts getting close to full
d) Environment: Battery may be too hot/cold, limiting draw
c) Some other issue (hopefully not)
If it is drawing lower than that, the factors could be
a) Amperage (somehow, your EVSE is limiting to lower amperage)
b) Voltage (I have seen 208, 220 and 240 in US)
c) Battery level: Volt starts tapering charge rate down as the battery starts getting close to full
d) Environment: Battery may be too hot/cold, limiting draw
c) Some other issue (hopefully not)