Charging rate using ChargePoint EVSE

[Blue20]

There are quite a few Charge Point EVSE in my town.

Most of them are 6.6 kW per port, and a few of them are sharing 6.6 kW between the two port.

From the ChargePoint app and the Chargepoint web site, I can see my car always drawing less than 6 kW. As i3 has a 7.2 kW onboard charger, just wondering has anyone successfully pulled 6.6 kW from ChargePoint EVSE?

My car has the KLE fix, and should be able to charge at max rate.

 

[jadnashuanh]

Power is a function of volts*amps. IF the voltage is down a bit from the design going into the unit (it could still be within specs), the max power will also go down. Depending on what your SOC was when you plugged in, the car may already have reached the point where it is reducing the charging rate to top off the batteries. Or, since you drove there, the batteries could be hot already, and it had to slow down while cooling them to prevent damage. Last, the pilot signal coming out of the EVSE could be slightly off, and the reported max current is a bit lower than design, and the car is just abiding by that signal and not drawing all it could from it. FWIW, the internal charging circuits in the i3 are rated at 7.4Kw.

 

[Jeffj]

Think I read somewhere that many (if not most) commercial circuits end up at 208V rather than 220 or 240. So 208V * 32 Amps equates to the 6.6 kW rating. But efficiency of delivery (probably 85%) makes the output closer to 5.6 kW. I have used these units in a number of locations and I get right around 6 kW charging, so that probably means 220V (5.984 after the 85% conversion). I have also seen slightly higher than 6 kW, so those must be on a 240 circuit (6.5 kW max output).

It really does depend on the circuit feeding the unit. Output could be as low as 5.3 kW on a 208V and 30 Amp circuit.

 

[jadnashuanh]

The EVSE is just a smart switch...if it's dissipating 15% internally, it has a major problem with the power contactor! But, there is a factor of efficiency IN the i3, where not all of the power going in gets to the batteries; some may go to cooling, some will be lost in the conversion of acv to dcv that actually charge the batteries. On most, they're displaying the actual power being delivered to the vehicle...they would have no way to know how much made it to the batteries.

 

[Blue20]

This is from this morning, charging from 20% to full. The plateau is just below 5.8kW. That's what the EVSE sending out. At 208V, that would be 27.8A.

The EVSE can deliver more, not sure why i3 is not calling for it.

 

[jadnashuanh]

The input voltage may not be 208vac. The i3, I think, won't draw more than 30A (32A peak - the way they measure it in Europe, we use constant, so a 30A EVSE is equivalent). If they did not adjust the pilot signal in the EVSE, and it was set up to allow a max of 6500W at 240vac input, that's 27A, essentially what the i3 was drawing. Most EVSE's out there are designed for a range of input voltages, but unless they adjust the pilot signal, it likely is set to report a level consistent with the maximum design input level, and, that's 27A.

 

[rome425]

This is from this morning, charging from 20% to full. The plateau is just below 5.8kW. That's what the EVSE sending out. At 208V, that would be 27.8A.

The EVSE can deliver more, not sure why i3 is not calling for it.

Unrelated question.
What app is that screenshot from?

 

[Blue20]

It is from ChargePoint.com, the website (not app)