Level 1 Home Charging

[ecotourist]

Just had a section of our driveway replaced (tree roots) and as a result haven't been able to get our Tesla Model 3 into the garage (where we have a level 2 charger) for quite awhile. But I was able to park about 30' from the house and have charged it during that time with a long extension cord and 120 Volts.

We've taken a few fairly long trips and charged it to 90% once, otherwise our usual 80%. I'm surprised how well it worked. It charges for hours of course but that's often through the night, so it's been no inconvenience at all.

It seems a 50 or 60 mile daily commute would be quite feasible with only a level 1 home charger.

 

[mclasser]

At home, I only level 1 charge my Lyriq. Been working fine for us and our driving style.

 

[MNgopher]

Only comment is to note that a level 1 charger is less efficient than a level 2 charger, so if given the choice the Level 2 charger will be ever so slightly more forgiving to the electric bill... (I say this as the owner of a Ford Fusion Energi Plug In Hybrid and use Level 1 at home).

 

[WobblyElvis]

I don't have an electric vehicle but.... If I had one, I would like to pre- heat the car before leaving the house in cold weather. I don't think this would be practical with only level 1.

 

[ecotourist]

I don't have an electric vehicle but.... If I had one, I would like to pre- heat the car before leaving the house in cold weather. I don't think this would be practical with only level 1.

You'd have to try it. The Tesla is back in our (unheated) garage where it doesn't need pre-heating so I'll never know.

 

[dogememe]

I’ve been doing L1 for years now. We are a two EV household with a single L1 charger and it’s no problem. Yes it takes days to charge if I go further than work or around town but it’s no problem.

 

[y_p_w]

Only comment is to note that a level 1 charger is less efficient than a level 2 charger, so if given the choice the Level 2 charger will be ever so slightly more forgiving to the electric bill... (I say this as the owner of a Ford Fusion Energi Plug In Hybrid and use Level 1 at home).

I've heard Level 1 can be up to 80% efficient while Level 2 is up to maybe 90%. Obviously that adds up over several years. Level 3 is even more efficient but impractical for most homes. And then it tends to reduce battery longevity.

 

[y_p_w]

I don't have an electric vehicle but.... If I had one, I would like to pre- heat the car before leaving the house in cold weather. I don't think this would be practical with only level 1.

Preheating the car or the battery? I'd seen battery preconditioning cycles on a Tesla Model 3 RWD while it was connected. Went up to maybe 15A being pulled in, while 32A is the max. I don't believe preheating the cabin is anywhere close to that.

You can do either, but it will just use power from the battery if there's not enough external power.

 

[Astro14]

When we bought the plug-in hybrid, we installed a level two charger.

Part of the reason is that our son comes down to visit from DC in his Chevy Bolt. Even if we plugged that thing in for 24 hours, or 48 hours, at level one, he couldn’t make it back home.

So, not only does the level two charger, allow him to visit more easily, it also allows us to recharge the plug-in hybrid in an hour or two, as well as adds a selling point for the house. Should we choose to do so.

I don’t see how I could get by with a level one charger if I had a fully electric vehicle. There are simply too many times when I want to take off and go somewhere, and the car would need to be over 80%. Further, dragging out an extension cord to a point far away from the garage is a total pain, where the heavier cable that’s ready to go off the Tesla is a piece of cake.

 

[jghall00]

Preheating the car or the battery? I'd seen battery preconditioning cycles on a Tesla Model 3 RWD while it was connected. Went up to maybe 15A being pulled in, while 32A is the max. I don't believe preheating the cabin is anywhere close to that.

You can do either, but it will just use power from the battery if there's not enough external power.

It probably depends on the vehicle. The resistive heater on my Focus Electric was like 6 kW. My Blazer pulls at least 1 kW for cabin conditioning. It could be 1.9, or it could be .99. I can't tell without using my OBD dongle. But I have L2 so I've never bothered.

 

[dogememe]

When we bought the plug-in hybrid, we installed a level two charger.

Part of the reason is that our son comes down to visit from DC in his Chevy Bolt. Even if we plugged that thing in for 24 hours, or 48 hours, at level one, he couldn’t make it back home.

So, not only does the level two charger, allow him to visit more easily, it also allows us to recharge the plug-in hybrid in an hour or two, as well as adds a selling point for the house. Should we choose to do so.

I don’t see how I could get by with a level one charger if I had a fully electric vehicle. There are simply too many times when I want to take off and go somewhere, and the car would need to be over 80%. Further, dragging out an extension cord to a point far away from the garage is a total pain, where the heavier cable that’s ready to go off the Tesla is a piece of cake.

So, I'll give some perspective. In our household we have two EVs: me and my ex.

Me? My work is like 3 miles away from home. Then I might go an extra mile or two for lunch or other errands. Once a week I go out of town, maybe 200 miles round trip tops. If it takes a few days to get back to 80%, I don't care.

Then my ex? He drives a lot (30K miles/year by our estimates) but can charge at all three of his jobs for free... I think he's charged at home maybe 3x since he got the car?

For either of us, we can drive 1 minute down the road to Tesla Superchargers if we have to, or plenty of other public charging. Would L2 be more efficient and convenient? Sure! But we rent and don't want to invest any $ in the situation. I might do a 240V 20A outlet at some point... but it's not a priority.

 

[ecotourist]

I don’t see how I could get by with a level one charger if I had a fully electric vehicle. There are simply too many times when I want to take off and go somewhere, and the car would need to be over 80%. Further, dragging out an extension cord to a point far away from the garage is a total pain, where the heavier cable that’s ready to go off the Tesla is a piece of cake.

It's true that a dedicated Level 2 charger is very convenient, hard wired to your garage parking space so to speak. It's even pretty fast.

But I was able to get by with only Level 1 charging using a long extension cord for about 3 weeks to a surprising degree. I was prepared to use the Supercharger located about half a mile away but just never needed to use it.

A dedicated Level 1 charger could have been set up the same as my Level 2 system. I have both a 240 Volt and a 120 Volt connector and a Tesla charge cable. [The 120 Volt connector and the charge cable came with our car.] I could have set up my charging station using that 120 Volt connector and the Tesla charging cable but I had installed the Level 2 plug-in before I took delivery of the car. It cost almost exactly $500 for parts and labour to install the 240 Volt plug-in and for someone who travels less than 60 miles most days, a Level 1 dedicated charge station might be all they'd need.

 

[ecotourist]

I might do a 240V 20A outlet at some point... but it's not a priority.

I have a 240 Volt, 40 Amp outlet. I could charge at 32 Amps (which is the Model 3s maximum on 240 Volts) and have done so in the past. But I now charge at 25 Amps.

When we had our floors sanded the guy used our EV charger's 240 Volt outlet and somehow damaged the 40 Amp breaker. When he was done I couldn't charge at 32 Amps any more without tripping it. So I replaced that 40 Amp breaker and while it works just fine at the full 32 Amps I have cut my charging rate to 25 Amps partly for the benefit of the battery and partly because I'm a bit freaked out about having had to replace that breaker. And anyway 25 Amps is more than enough for our needs.

 

[GrumpyCat]

Only comment is to note that a level 1 charger is less efficient than a level 2 charger, so if given the choice the Level 2 charger will be ever so slightly more forgiving to the electric bill... (I say this as the owner of a Ford Fusion Energi Plug In Hybrid and use Level 1 at home).

Yes, less efficient because the vehicle has to power up the same control circuits for L1 as L2, a 100W to 300W overhead. Then with only 1440W available one gets less for the battery. Or take the same overhead out of 240V 40A 9600W, a much higher percentage of power is available for the battery.

 

[The_Jeff]

The so-called L1 charger that came with my Prius Prime is 240V tolerant--- it's just got a 120V plug on it for the US market. Technically the charger's just a cord with a relay box and couple sensors-- the AC/DC converter is within the car.

I have a 240v male to 120v female adapter so I can use the charger as a poor man's L2.

If yours supports this, you could have an adapter at the house end of your extension cord and do a low amps charge that's still 2x as fast.

 

[JeffKeryk]

Prospective owners have been asking me about Tesla ownership since Dec 2018. I've learned a lot.
I ask them, "How ya gonna charge?" You might be surprised at some of the responses...

Anyways, I advise people to get serious about EV ownership. Check with an electrician for accurate charging guidance on your home's properties; you need to know! On a side note, find out about auto insurance; it can be nasty!

I used a NEMA 14-50 with the mobile charger for a few years and then had the Wall Connector installed. 33-35 MPH charging. Oh yeah, the juice is from that big nuclear reactor up in the sky...

Having said that, the family across the street never plugs in their Bolt; the wife has free charging at her local government job parking lot.
A friend at work never charged his at home; many companies around here offer subsidized or even free charging.

So it depends on your use case. But do be realistic. The number 1 reason EV owners go back to ICE is charging issues.

 

[SC Maintenance]

Very interesting. Level one might be a higher possibility in Apartment complexes, etc - especially in older parts of town with aging infrastructure and limited excess electrical capacity.

Can someone explain why level 2 is more efficient. Usually charging a battery at lower power levels is more overall less energy efficient? Lower power usually generates less heat (energy loss)?

 

[JeffKeryk]

Very interesting. Level one might be a higher possibility in Apartment complexes, etc - especially in older parts of town with aging infrastructure and limited excess electrical capacity.

Can someone explain why level 2 is more efficient. Usually charging a battery at lower power levels is more overall less energy efficient? Lower power usually generates less heat (energy loss)?

Level 2 charging is more efficient than Level 1 because it uses a higher voltage (240V vs. 120V), which allows for faster charging with less energy loss. This higher voltage means the current is lower for the same amount of power, (I = P / V) and the use of thicker wires and dedicated circuits reduces resistance and heat, resulting in a higher grid-to-battery efficiency.

I'm sure the electrical engineers around here can offer a much better explanation; this is my best shot. Anything more is above my pay grade.

 

[MNgopher]

Very interesting. Level one might be a higher possibility in Apartment complexes, etc - especially in older parts of town with aging infrastructure and limited excess electrical capacity.

Can someone explain why level 2 is more efficient. Usually charging a battery at lower power levels is more overall less energy efficient? Lower power usually generates less heat (energy loss)?

Because the process of charging typically involves some power transformations (Ie: AC to DC to get to the battery for Level 1 or Level 2 chargers and other items, like running cooling fans to keep the battery cool during the charging process.) In the slower level 1 charging scenario you run that equipment much longer - and that energy isn't free...

Again, its like a 5% difference in efficiency between Level 1 and Level 2, but its there...

 

[GrumpyCat]

Can someone explain why level 2 is more efficient. Usually charging a battery at lower power levels is more overall less energy efficient? Lower power usually generates less heat (energy loss)?

Has nothing to do with higher voltage being more efficient and everything to do with more power being available on L2 than L1. The vehicle charging system must power up to manage charging. This overhead consumption is typically 100W to 300W whether one is connected to 1.44kW or 9.6kW.

So doing the math say only 100W is needed to power up the vehicle charging circuits.

L1:
1440W - 100W = 1340W
1340 / 1440 = 93% of provided power available to charge battery

L2:
9600W - 100W = 9500W
9500W / 9600W = 98.96% available for charging the battery

If 300W is needed then L1 is 79% and l2 is 97%.