ChargePoint Level 1 - Slower than normal?

[Pipcecil]

I frequent a restaurant that is in the same shopping center that has a ChargePoint Level 1. Usually I wouldn't care about a Level 1, but since the distance to this favorite place is far and the station is free, I figured why not (we usually stay about an hour, and yes its ONLY a level 1).

I was looking over my usage reports and noticed a small descrepancy with the kWh my car would receive from this unit. ChargePoint station Level 1's required you to use your own portable EVSE so we just use the Leaf portable EVSE. The public Level 1 stations are NEMA5-20R (so 20 amp with neutral line). Charging on three separate occasions yielded only 0.665, 0.679, and 0.693 kWs (the charging sessions 57:48, 58:33, and 60:10 minutes, respectively). I thought ~0.69 kW per hour is extremely low, I should almost be getting double that? 1.1 kW per hour? It was calculated here on the forum that the portable charger is only running @ 78% efficency, I don't know if that is before the 1.1 kW rate or after, but even if it is before, that should give me 0.858 kW in one hour into the battery.

Anyone know why the efficiency is low? Car SOC is usually around 60-70% (5-8 bars). Charging doesn't slow down to ~80% correct? I never get to this place with 9 or more bars remaining (my 80% with 2 capacity bars loss).

 

[Nubo]

Where are you getting the kWH figure? From the Chargepoint display?

Did you notice a difference in the guessometer range after charging?

 

[Pipcecil]

Both the display plus their logs in the account information. Unless their logs for their stations are incorrect, I have to assume these are accurate.

I did notice a few miles difference, but its a Level 1 so i am not expecting it to change much, I don't pay too much attention to the guessometer. I am guessing the difference would be ~1-2 miles given the kW difference expected, and the guessometer wouldn't have that accuracy. If I sped too much at the end in the parking lot I would get the difference..

 

[davewill]

It was calculated here on the forum that the portable charger is only running @ 78% efficency, I don't know if that is before the 1.1 kW rate or after, but even if it is before, that should give me 0.858 kW in one hour into the battery.

Since the Chargepoint is reporting the wall power supplied, before any charger inefficiencies, so it should really be 1.4kWh (12a*120v = 1.44kw) for your hour of charging. The only way the Chargepoint unit COULD reduce your charge rate would be if the voltage were low, and I can't see it being THAT low. I'd be inclined to question their reporting of the kWh delivered.