Is level 1 charging a viable long-term option?

[MP3Mike]

I may try to see if another electrician may have another a better approach to this issue that does not require so much work and trenching.

Good plan. You might ask them to look into the possibility of upgrading one of the outlets in the garage to a 6-20. As other have said, if you can do that it shouldn't cost a lot, and you would be in good shape. (I am currently using a 6-20 because I have been too lazy/cheap to install the Tesla wall connector that is sitting in my garage.)

 

[Wanderer]

95ft of trenching for $3k? That's $31.58/ft. Are you using a tunnel boring machine?

I honestly was also shocked by the quote. It is the only company I can find around here that is willing to do it and even then I have to wait about 6 weeks before they can come by. I asked a couple of other companies and they said no as soon as it was more than 40feet. I was expecting a quote of $500-$1,000 myself. I was already resigned to the notion of having to do excessive electrical work due to the location of the garage and the local code, but the additional trenching cost made me not want to proceed.

 

[Wanderer]

It can work. Can you see if you’ve got any receptacles nearby that are connected to a 20A breaker, or, even better, actually have a nema 5-20 receptacle (the left blade has a horizontal notch)? If so, then charging at 16A is much better.

I looked earlier today based on your suggestion and unfortunately I do not have a nema 5-20 receptacle in the garage. The garage has very few outlets - two sets of two regular outlets (without the notch). Apart from those two outlets, there is an electrical garage door and a light. That’s about all the electrical in or even near the garage. I haven’t figured out the breaker, yet, but it seems unlikely there will be a 20A breaker. I will see if I can find what breaker(s) the garage is hooked up to when I have some time to study the electrical panel. As I am by no means an expert in this, I hope the electrical panel is decently labeled.

 

[Wanderer]

Good plan. You might ask them to look into the possibility of upgrading one of the outlets in the garage to a 6-20. As other have said, if you can do that it shouldn't cost a lot, and you would be in good shape. (I am currently using a 6-20 because I have been too lazy/cheap to install the Tesla wall connector that is sitting in my garage.)

Thank you for everyone making that suggestion. I did not know that the 6-20 might be an option and that sounds as if it may possibly be a much cheaper upgrade. It won’t charge as well as a level 2 charger, but may be sufficient for my needs.

 

[Wanderer]

How many circuits do you have running out to the garage now? If more than one I’d investigate the feasibility of switching one to 240v like @beatle suggests above. A 6-15 or 6-20 would be a big improvement and alleviate pretty much all of your concerns.

I don’t know yet, but fair question and I will try to figure it out. I fear it is only one circuit considering the very limited electrical outlets in the garage.

 

[WyoDude]

I have been a happy owner of a 2016 Model 90D S for the last seven years. After 110,000 miles the car is still doing great and I have had very few issues with it. I had a 240V NEMA 14-50 socket installed in my garage as soon as I got the car and have been charging my car with the mobile charger that came with the car every night. This has been working very well for me - it is always “fully“ charged when I take it out.

I am now moving to a new home and had expected to just install another level 2 charger there, this time a hardwired one. However, I was shocked how much it will cost me to do so. Due to the layout of the house and garage combined with city ordinances for electric installations, it will cost me close to $10,000 to install a level 2 charger in the garage. The costs are due to the need to dig a 95ft trench combined with the installation of two additional sub-panels, one at the house (as there is no space in the existing one) and one in the garage (due to local city ordinances). The trenching alone will cost me $3,000.

Considering this very high cost, I am considering whether I can get by with just doing level 1 charging with the mobile charger. I also have a supercharger very close to my home and another one on my way to work. I commute about 70 miles a day, but typically only three days a week, usually Monday, Tuesdays and Thursdays. How much I drive during the weekend really varies from week to week but it would be typically not more than 100 miles. I typically charge to about 90% to avoid hurting the battery giving me a theoretical 214 miles of driving distance, although from experience I know the actual distance varies significantly dependent on temperature and driving conditions. My understanding is that level 1 charging should add about 2-4 miles per hour. This seems really slow, but my thinking is that if I am fully charged by Monday mornings and plug in whenever I am at home, I should be able to get sufficient charge to get by during a typical workweek and most weekends and I can always use the supercharger to top up when I need more.

I have been reading some threads on the forum and did read that level 1 charging is less efficient, but it is not clear to me if it is is meaningfully less efficient to justify investing $10K in a level 2 charger.

I am a bit uncomfortable going from doing what I have been doing for 7 years, charging my car every night and having a full charge every morning, to moving to trickle charging and “hoping it will be sufficient” but am also reluctant to spend that kind of money on something that I may not need. Is anyone else in a similar situation and does it work for you? Is is bad for the battery to charge continuously on a level 1 charger whenever I am home? Are there any other alternatives or other considerations?

Thank you for any insights!

How many quotes did you get?

 

[Cheburashka]

Absolutely not.

You have to make sure that the entire circuit can support the additional current and commonly, they can't

Depends on if the house is new enough. Mine is newer and all circuits are 20a. I just used a basic nema15-20a adapter to convert the outlet and charge at 20a (for my motorcycle)

 

[Cosmacelf]

Depends on if the house is new enough. Mine is newer and all circuits are 20a. I just used a basic nema15-20a adapter to convert the outlet and charge at 20a (for my motorcycle)

You mean you used a cheater extension cord to plug into a nema 5-15 to give a nema 5-20 receptacle outlet for the Tesla nema 5-20 adapter and charged at 16A? That’ll work, but the receptacle isn’t rated for that current, I’d recommend swapping out the 5-15 receptacle and replacing it with a 5-20 receptacle.

 

[NewbyMaybe]

If you qualify for tax and or grant incentives and you don't have a shade tree in the wrong place then a power wall and solar could be the answer.

 

[Krash]

Could you level 1 charge at work with your or a second mobile adapter?

 

[airborne spoon]

I was fine with a 120v plug and I set the car to draw 10A. For 4 years I did this. It worked pretty good, however I also worked 2 miles from my house so I wasn't burning off much juice.
Every night I was gaining about 15% on my 85 pack this was plugin at 1600 and unplug at 0830.

The cost for your install seems insane by a longshot. Also perhaps you could dig the trench yourself the old fashioned way to save a few bucks. Also what the gov doesn't know won't hurt you. I installed a HPWC at my mom's house for $400 in parts it was a 30ft run and I DIY the entire thing. But we don't need permits for simple *sugar* like that around here.

 

[Wanderer]

If you qualify for tax and or grant incentives and you don't have a shade tree in the wrong place then a power wall and solar could be the answer.

Interesting idea. I don’t think trees will be a problem. Would I be able to put a Level 2 charger on such a system? May be cheaper in the long run than running the cable from the house!

 

[Wanderer]

Thank you all for your suggestions and feedback. This community always impresses me!

You can’t upgrade the breaker without also upgrading the wiring, so not a possibility. But it is fairly common to use 15A receptacles on 20A breakers, so do check the breaker (which is a job in itself since most electrical panels aren’t labeled very well!). If you do have a 20A breaker, then you can upgrade the receptacle to a 20A receptacle and use the Tesla nema 5-20 adapter with the mobile connector to charge.

I managed to study the electric panel today. Luckily everything is really well labeled so it was not that difficult to figure out what was going on. I found three breakers for the garage:

• A 20A breaker for the garage outlets (I find two times two outlets in the garage)
• A 20A breaker for the garage doors
• A 15A breaker for the garage lights

Currently, none of the receptacles in the garage are 5-20. However, if I understand correctly it may be possible to change one of the outlets to a 5-20 receptacle, assuming the wiring is the right gauge, to get 16A which would be an improvement.

The new electrical code specifies the outlets, lights, and apparatus must be on their own separate branch circuits. It also encourages the use of 12 gauge wire with 20 Amp service for branch circuits. So if your circuit breaker box has 15 Amp breakers you cannot replace it with a 20 Amp breaker unless you run new wiring. I have seen 15-20 Amp outlets installed on 15 Amp circuits. This a fire hazard due to wire heating. Also note that regardless of wire gauge the length of the circuit from circuit breaker box to outlet will determine ultimate allowable amperage. The longer the circuit the less amperage is allowed. Charging a Tesla (or any EV) is a unique electrical load as it is constant, up to 80% load, and the load is constant for hours.

Thank you for those details. The garage was built in 2019 so is likely aligned with the new electrical code so it may be 12 gauge on the 20A breaker, which would help. The distance may be too high to be able to drive up the amperage, though. I will check with a qualified electrician.

Even in a full breaker box you can usually convert the 120V outlet to 240V. In the example below, if you had two 15-amp breakers side-by-side you can this quad breaker. It provides two 15-amp 120V circuits plus a 20-amp 240v circuit. In this case you connect the existing 15A circuits and the garage outlet to the 240V posts - and you also free up the old 20-amp breaker. There are many other combinations to choose from, as well a tandem breakers.You should be able to find what you need. Just remember that a new 240V outlet needs to be dedicated, that is nothing else can be supplied by that breaker.

This is intriguing. I also read in anther tread different possibilities to upgrade to 240V. Not sure what is possible in my configuration, but I will ask the electrician. I my electric panel, it has two 20A breakers side by side - one for the garage outlets and another one for the garage door.

 

[ewoodrick]

Depends on if the house is new enough. Mine is newer and all circuits are 20a. I just used a basic nema15-20a adapter to convert the outlet and charge at 20a (for my motorcycle)

No it doesn't. It depends on the electrician who wired it.

Using a 15 to 20 adapter is asking for trouble. While the wiring may be rated for 20A, the plug isn't.

 

[Cheburashka]

You mean you used a cheater extension cord to plug into a nema 5-15 to give a nema 5-20 receptacle outlet for the Tesla nema 5-20 adapter and charged at 16A? That’ll work, but the receptacle isn’t rated for that current, I’d recommend swapping out the 5-15 receptacle and replacing it with a 5-20 receptacle.

I agree that it is not rated for this. However there is also no way a modern 15a receptacle isn't built to take 20a.

I've been using this setup daily for 2 years without issue.

I do agree I should probably change the outlet to a 20a but haven't gotten around to it.

It sounds like OP is in the same situation as me. Newer construction, everything rated 20A. I bet his wiring is 12 gauge too just like mine. Common in newer builds.

 

[maximizese]

Any chance setting up level 2 charging somewhere else on the property other than the garage that would be less labor and cost intensive? You could always level 1 charge in the garage overnight or for the days you're home, but level 2 when you know you'll need to charge 6X faster. Not sure what your property looks like or if the whole panel or sub panel needs to be added or modified no matter what. When I had my 4.8kW solar array installed back in 2016, the contractor I went with not only undercut the big box solar companies by 25%, but also included a sub-panel and 60ft 50A line with 14-50 receptacle for no extra charge. It took 2 guys about 40 minutes to setup the EVSE line, run it through the attic, and install the receptacle. The city inspector took a look and signed off on it. Now I can charge both our Model S and Fiat 500e whether they are parked in the two separate garages or on the two driveway spots.

 

[scottf200]

Thank you all for your suggestions and feedback. This community always impresses me!

I managed to study the electric panel today. Luckily everything is really well labeled so it was not that difficult to figure out what was going on. I found three breakers for the garage:

• A 20A breaker for the garage outlets (I find two times two outlets in the garage)
• A 20A breaker for the garage doors
• A 15A breaker for the garage lights

Currently, none of the receptacles in the garage are 5-20. However, if I understand correctly it may be possible to change one of the outlets to a 5-20 receptacle, assuming the wiring is the right gauge, to get 16A which would be an improvement.

I'd still consider going to a 6-20 instead of a 5-20. Pretty big difference in charging speed (x2.5).
If you are in a place that requires conduit then it seems they could even pull another wire ... my thinking is to have 120v (5-20) and 240v (6-20) receptacles.

 

[Cosmacelf]

The OP can’t convert his 20A garage receptacles to 240V without losing all his garage plugs, which would be a stupid thing to do. Read his latest post.

@Cheburashka is right that you can draw 16A from your 15A receptacles since they are wired to a 20A breaker (I am assuming that the electrician did it correctly and used 20A wire, and for a garage built in 2019, that’s a very safe bet). You’d use something like this along with the Tesla 5-20 adapter.

But it is really easy to replace one of your garage receptacles with a 20A receptacle. Just flip off the breaker first. Btw, by code, the garage receptacles should be GFCI protected which could be by a GFCI breaker or by a GFCI receptacle.

 

[scottf200]

The OP can’t convert his 20A garage receptacles to 240V without losing all his garage plugs, which would be a stupid thing to do. Read his latest post.

But I mentioned a question of conduit so they could pull another phase for the 2nd line of 120v power.

Phase A & B for the 240v NEMA 6-20 Tesla charging
Phase (A or B) & neutral for the 120v NEMA 5-20 normal garage outlet.

Essentially in my garage my subpanel has both a 240v plug to charge my Tesla and another breaker in it to a 120v plug to charge our Volt.

 

[jeremymc7]

My house was wired with 20A wire but with 15A outlets and breakers. I was able to swap the outlet and breaker to 20A in the garage and buy the $35 Tesla 20A adapter for my mobile charger.

Sure it’s not going to be anywhere near what you had before but any improvement is something and might just be enough to make the difference for you.

Have someone come out and tell you if it’s possible in your place.

I don’t drive 300 miles every day so the nightly trickle charging is more than enough to get me though the week. I also have numerious SC near me, along routes and at my destinations.

Nicely my work also has free 30A charging just down the street, even though I’m work from home.