I looked around and saw a lot of posts about slow DC charging, but what about AC? My car was charging at home overnight at 1.8 kW. It only went from 20% to 29% in 12 hours. If the battery is 65 kWh, that means I only got 3.24 kWh in that time. Am I missing something here? Appreciate any help.
Charging always slows down when it’s cold. A level 2 charger would make a big difference. If it’s cold enough, some of the power just goes into keeping the battery warm instead of charging. 1.8 kW is a level 1 charge.
@Vesper
That makes sense. Thanks for explaining.
Just a heads-up… charging speed is measured in kW, battery capacity in kWh.
Arielle said:
Just a heads-up… charging speed is measured in kW, battery capacity in kWh.
Appreciate it. I posted this half-asleep and annoyed.
Check your charger settings. Some have a button to adjust the amps. If it’s set too low, it’ll charge slower. Mine goes up to 10 amps.
Vic said:
Check your charger settings. Some have a button to adjust the amps. If it’s set too low, it’ll charge slower. Mine goes up to 10 amps.
Thanks. The car and app both show it charging at 1.8 kW.
@PixelPaladin
If you adjust the amps on the charger, you might be able to get around 2.1 kW.
Clancy said:
@PixelPaladin
If you adjust the amps on the charger, you might be able to get around 2.1 kW.
Good to know. I’ll check the settings and report back.
Low temps and low power are a bad mix. Lower charging power means more energy loss. I tested this after installing a level 2 charger—at 3 kW, I lost about 19%, but at 11 kW, it dropped to 9%. If I start charging right after a long drive, losses go down to 5%.
What was the outside temperature? When I charge on a regular AC charger in cold weather, the first 15 minutes just heat the battery before charging even starts. If it’s really cold, most of the power might be going to heating instead of charging.
Might be worth using an OBD scanner to check battery temp.
@Reagan
Didn’t think about using my scanner. I’ll check. Thanks.
Edit: It was around 18°F overnight.
PixelPaladin said:
@Reagan
Didn’t think about using my scanner. I’ll check. Thanks.
Edit: It was around 18°F overnight.
Try connecting to CarScanner and check the total energy charged. Compare it to what your charger reports—you might be losing more power than expected.
I haven’t noticed AC charging getting slower unless it’s extremely cold. I still get 11 kW on level 2 unless too many people at work are plugged in, then the chargers split power.
Just a small math correction… 9% of 65 kWh is 5.85, not 3.24. Still not much, but almost twice what you thought.
Are you sure your EVSE is set to 16A? That loss seems higher than expected.
Ren said:
Just a small math correction… 9% of 65 kWh is 5.85, not 3.24. Still not much, but almost twice what you thought.
Are you sure your EVSE is set to 16A? That loss seems higher than expected.
I teach math, but apparently, I shouldn’t do it right after waking up. Thanks. I’ll check.
Is this Gen 1 or 2? The newer models have a setting to lower charge speed. Might be worth checking.
I’ve only seen slow AC charging when a setting is limiting it. Maybe your EVSE is telling the car to charge at a lower rate? It does this to prevent overloading circuits, but if something’s wrong, it might be limiting output.
One more thing… if you’re using a 220V plug, one of the hot wires might be loose, cutting the power in half. You might want to check the outlet and breaker just to be safe.
@Tai
Would that still be the issue if the car says it’s pulling 1.8 kW? Both the dash and my electricity usage confirm that number.
It was below 20°F last night, so I figured the cold was the problem. Seems like a lot of power is going somewhere other than the battery (maybe heating it up).