Level 2 Charging stations in the USA. Underpowered?

So we travel to a city about 60 miles from us where they have a lot of Level 2 chargers installed downtown. We find the charger we were looking for, plug in and go about our shopping and eating experience.

2 hours later, we return to the i3 to find the charge recouped during the 2 hours was far less than what we expected based on calculations given for most Level 2 charging stations. The i3 was set to Maximum and 'Charge Immediately' so we started wondering...

Could it be that a LOT of Level 2 chargers installed were set to charge at 3.6kwh instead of the Maximum of 7.2kwh because the first generation of EVs could not charge at the higher rate?

Its likely you have the KLE patch that derates the onboard charge rate to 70% of maximum depending on heat. See http://www.mybmwi3.com/forum/viewtopic.php?p=11467#p11467

Thanks jackt.

Level 2 just means it is using 240vac input, it has nothing to do with the actual max current the unit can provide. Level 1 means it's using 120vac as the input, and that is not as efficient trying to make 400vdc required to recharge the car. You'll experience the same issues with the CCS (DC fast charge) units. On ac, the car can handle 7.4Kwhr...on DC, it can handle 50Kwhr, but not all units support those maximum values. Note, you can use a unit that can provide more...there's a signal provided by the EVSE that tells the car how much is available, and then the car won't ask for more than that from it, but the car will decide how much it wants at any particular time based on the current charge level, what you may have set it to, and the current temperature.

jadnashuanh said:

Level 2 just means it is using 240vac input, it has nothing to do with the actual max current the unit can provide...

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Commercial power in the US is commonly 208 volts. 208 and 240 AC volts would still be considered level 2 AC charging.

jadnashuanh said:

On ac, the car can handle 7.4Kwhr...on DC, it can handle 50Kwhr, but not all units support those maximum values.

Click to expand...

To avoid confusing others, to partly quote someone else:

kW and kWh are very different metrics. It's the same as confusing gallons with horsepower. Think of kW = horsepower, kWh = gallons.

i3 has a ~22 kWh capacity battery pack w/18.8 kWh usable (http://www.bmw.com/com/en/newvehicles/i/i3/2013/showroom/technical_data.html and http://insideevs.com/bmw-i3-bev-official-epa-rating-range-81-mpge-124/)

(BTW, 1 hp = ~0.746 kW. And, http://www.fueleconomy.gov/feg/evsbs.shtml says 1 gallon of gasoline=33.7 kWh.)

trunkrecords said:

Could it be that a LOT of Level 2 chargers installed were set to charge at 3.6kwh instead of the Maximum of 7.2kwh because the first generation of EVs could not charge at the higher rate?

Click to expand...

What brand were they? Have some Plugshare links to them?

Some Blink EVSE had their output turned down due to faulty Rema handles. Although 16 amp 208/240 volt public EVSEs aren't common, it's also possible they were http://insideevs.com/chargepoint-introduces-ct4000-series-charger-with-unique-power-sharing-option/ with power sharing enabled (and another car plugged in) or those CT4000s hit a bug where they weren't emitting the proper pilot for 30 amp charging.

As for 1st generation... FWIW, even though the '11 and '12 Leaf only had a 3.3 kW on-board charger, some other fairly early EVs had 6.6+ kW or beyond on-board chargers (e.g. Tesla Roadster, Fit EV, Coda, Ford Focus Electric, ActiveE etc.)

You can get an idea of the output power based on the time to full charge relative to your indicated current battery status that gets displayed momentarily on the main screen once you start a charge cycle. It often takes a few minutes to stabilize.

Regardless of how the car is configured, it will never try to pull more power than the EVSE announces it has, so if there's an issue with that (faulty ground, incorrect levels, etc.), that can limit or even stop a charge cycle completely.

I had much the same experiences with our i3 (its three weeks old) I noticed it was only charging just over 3 kW but was over 5kW when We bought it. It came with the software fix installed. BTW the dealer did not inform us of the charging problem with KLEs or the fact the car charging rate was lowered from 7.4 kW to 5 kW. BMW sent out the suspicious email and it caused me to investigate.
The KLE is bad and BMW is trying to find another. The service manager told me when the KLE fails, the MLE charges just over 3 kW. I wonder how many i3 owners have bad KLEs and don't know it as they might charge all night and don't realize it is taking 8 or so hours. I only found this issue after days and days of calls with BMW. Our home automation system monitors our breaker panel so It told me the car was charging at 3kW not the 5kw or 7kw expected.
I am very surprised the i3 does not have an active display of charge rate. If you pulled into a public type 2 charging station and it was not at full 7kW power or the two systems did not sync up how would you know? I know many of the charging stations show initial charging rate, but it seems every one i use is in the sun and the screen is washed out.

Doesn't the secret screen show the current charging rate?