jasleinstein wrote:KurtEndress,

Sorry I should have referred to my earlier post. I am trying to see if buying the Clipper Creek 1.9kW charger will help my charging rate.One of the folks at Clipper Creek thought the i3 would not charge at a rate over 1.4 kW on 120v, regardless of which EVSE was used. .

Has anyone measured a charging rate over 1.4 kW using 120 for their i3? If so what EVSE were you using? How did you measure it? I have both a TED 5000 and good old fashion digital Fluke ampmeter.

I just looked at my charge rate. I ran the batteries down to 15 miles. Using the EVSE that came with the car, plugged into a 20 amp 120 circuit it is scheduled to take 28 hours to charge the car. ugh.

thanks

The quote below is from a email sent to me by the i genius about charging:

_____________________________________________________________________________________________________________________________________

"Finding the Charge Time for an EV

Amps * Volts = Watts (per hour)

This will be the rate of charge. Since the i3 has an 18.8 kWh battery capacity, we will then divide 18.8 by the rate of charge to get the number of hours it will take.

*Since the battery is measured in kilowatt-hours, we need to make sure we divide our answer in Watts by 1000 so we are using the same units.

So there are 3 settings for the charging rate in the car, which equate to 8 amps, 10 amps, or 12 amps. The voltage is constant at 120, and we just do the math from there.

So if the car is set to use all 12 amps for maximum charging rate, we can 120V * 12A, which equals 1440W (1.44 kW) per hour.
We know that EV charging as a whole has about 81% efficiency. So we'll multiply the watts per hour by the efficiency to get a more realistic rate of charge, which gives us 1.44 (.81) = 1.1664

The usable battery is 18.8 kWh, so 18.8 / 1.1664 = 16.12 hours to charge.
If they have their i3 set to charge at 8A, we do the same thing.

120V * 8A = 960W (.96 kW)

.96 (.81) = 0.7776

18.8 / .7776 = 24.177 hours"

Everything I have heard and found says the max draw for 120 charging is 12 amps max, but in the calculation the i genius did not take into account the slow down of the charging rate over that occurs during last 10 to 15 % to full! So the calculated 16.12 hrs will be longer! However the 28 hrs seems way too long unless something isn't working right.