12A at 110V slow charging: 3% takes 7 hours

[llamas]

I have a mobile connector on a ~12A circuit which charges my Model Y from 70% to 80% in 4-6 hours.

When I plugged it in tonight I noticed that it’ll take 7 hours to go from 77% to 80%. It still shows 12A at 110V. Everything plugged in correctly. Any thoughts?

 

[E90alex]

Might be because it’s getting cold enough that it has to warm the battery to charge it better.

 

[father_of_6]

You should look at getting a hardwired 220v EVSE. In cold climates, a 120v EVSE can waste all of its energy trying to get the battery up to temp.

 

[Tronguy]

Not unexpected. Let’s see: 15A socket; check. Max draw by NEC code: 12A, check. (80% of 15A).

Power into the car: 120V x 12A = 1440W, check.

Car’s rating per mile: 280W-hr/mile.

Miles of charge per hour: 1440/280 = 5.1 miles/hour.

Car’s range rating: assuming 330 miles.

Percent per hour: 5/330 = 1.5%/hr.

What you’re getting: 10% in 5 hours = about 2%/hr.

Working pretty much as advertised.

This is why something like a NEMA14-50, which, with a mobile connector, can deliver 32A@240VAC = 7680W, is so much faster: that’s 27.4 Miles of charge per hour, 8.4%/hr, and in 5 hours, that’s 42%. A Wall Connector on a 60A, 240VAC circuit. Which can deliver 48A, gives 11.52kW, 41 miles/hr, 12.1%/hr, and about 62% in 5 hours.

Finally: the other reason a 120@12A charging rate isn’t such a great idea happens to be cold weather. Below freezing somewhere the car has to warm the battery in order to charge it. I’ve actually seen the charge rate on a 120@12A circuit decline to 1 mile of charge per hour at 20F ambient, or less. The power available at 240VAC is more than enough to warm the battery so that kind of problem is minimized.

 

[Cosmacelf]

Because it is cold and the car needs energy to warm the battery. You are finding that 12A/120V charging isn’t great in your area. Either see if your garage plugs are connected to a 20A breaker (in which case you can charge at 16A), or look into 240V charging options.

 

[fholbert]

I’ve plugged into a 120v/15a circuit for several hours in 80* weather, I get a whooping 2mph. Not worth my time.

 

[terranx]

If this is a dedicated outlet and you have access to the panel, might be worth changing to a 240v breaker and swapping the outlet for a Nema 6-15. Or 6-20 if it happens to be 12ga wire in there. Upgrade could be done for <$50 and it would increase your charging speed significantly.

 

[fholbert]

If this is a dedicated outlet and you have access to the panel, might be worth changing to a 240v breaker and swapping the outlet for a Nema 6-15. Or 6-20 if it happens to be 12ga wire in there. Upgrade could be done for <$50 and it would increase your charging speed significantly.

I don’t have discrete access to the breaker panel. I do have a 240v/50a Wall Charger at my house. I thought buying a Mobile Charger to use free 120v electricity at my hangar was a good idea. Nope, the payback on the price of the mobile charger is about 44 years.

 

[jcanoe]

Your voltage is low; 110VAC instead of 120 to 123 VAC. The lower AC voltage will increase charging times by roughly 10%.

 

[fholbert]

Your voltage is low; 110VAC instead of 120 to 123 VAC. The lower AC voltage will increase charging times by roughly 10%.

I’m five hangars from the breaker box, ~260’. I think the length of the run is killing me.

 

[jcanoe]

The hangar roof could be used for solar panels.

 

[jcanoe]

I’m five hangars from the breaker box, ~260’. I think the length of the run is killing me.

Is the current 120V (~110V) circuit dedicated to EV charging? If there are no other receptacles/devices on the same circuit then the circuit can be easily converted to a 240V (~220V) circuit without any additional wiring. That would double the power available for charging to ~2.4kW (up from the current estimated maximum of 1.2kW) and cut the charging time in half.

 

[fholbert]

Is the current 120V (~110V) circuit dedicated to EV charging? If there are no other receptacles/devices on the same circuit then the circuit can be easily converted to a 240V (~220V) circuit without any additional wiring. That would double the power available for charging to ~2.4kW (up from the current estimated maximum of 1.2kW) and cut the charging time in half.

No. The outlets in four hangars are on the same circuit. Microwaves, refrigerators, coffee makers, tools…

 

[Unclepaul]

Switching to 240 v. Charging would speed things up.

In cold weather, often 120V charging can barely keep up.

 

[davewill]

No. The outlets in four hangars are on the same circuit. Microwaves, refrigerators, coffee makers, tools…

Then on top of everything else, you're likely to pop the breaker someday. The only reason you haven't is probably that most commercial 120v circuits are 20a, but the car, plus one microwave could be enough to do it.

 

[fholbert]

Then on top of everything else, you're likely to pop the breaker someday. The only reason you haven't is probably that most commercial 120v circuits are 20a, but the car, plus one microwave could be enough to do it.

If the car is charging, I'm flying.

 

[Resist]

There is no such thing as 110v/220v in the U.S., it's been 120v/240v for many, many, many decades now.

 

[Cosmacelf]

There is no such thing as 110v/220v in the U.S., it's been 120v/240v for many, many, many decades now.

Preach brother! I fear it is a lost cause though. I’m going to start taking about 100v/200v just to be a dick. If I do that often enough someone will say something like, “but wait what is the correct voltage number?” My life will be complete at that point.

 

[Rocky_H]

There is no such thing as 110v/220v in the U.S., it's been 120v/240v for many, many, many decades now.

We're about at the point where you get to use the magical "C" word: century.

 

[Kupe]

There is no such thing as 110v/220v in the U.S., it's been 120v/240v for many, many, many decades now.

220, 221 - whatever it takes.