evse recommendations?

[bldxyz]

So, now I'm talking to electricians and a sticking point has come up:

My house has 100amp service, total. The main panel is 100amps!

Electrician told me that a 50amp circuit for the EVSE would create a fire hazard, since that would leave only 30amps for the rest of the house (using an 80% rule). He's recommending I only get a 30amp circuit.

Doesn't that mean my EVSE would max out at 24amps? For the SE, we're talking about 77% of the capacity of the car to take in the electricity, so might that linearly increase my recharge time by about 30%?

 

[Lainey]

Yes it would max out lower. I am lousy with numbers (dyslexic) so won't confirm time. Keep in mind too that the cars do not charge full level towards the end so it could make it harder to guess full 100% charge times.

Did you discuss upgrading your service? I had family that had to do it.

 

[bldxyz]

Did you discuss upgrading your service? I had family that had to do it.

The guy quoted upgrading the service at about $4500, so I'm a bit underwhelmed by that idea.

 

[F14Scott]

So, now I'm talking to electricians and a sticking point has come up:

My house has 100amp service, total. The main panel is 100amps!

Electrician told me that a 50amp circuit for the EVSE would create a fire hazard, since that would leave only 30amps for the rest of the house (using an 80% rule). He's recommending I only get a 30amp circuit.

Doesn't that mean my EVSE would max out at 24amps? For the SE, we're talking about 77% of the capacity of the car to take in the electricity, so might that linearly increase my recharge time by about 30%?

Since the SE maxes out at about 32 Amps (for easy math's sake), your 24 Amp limitation would mean you would charge about 75% as fast. Real world, instead of the four-hour-ish charge, now you could expect the five-hour-ish charge. Not a big deal.

I tell everybody who will listen that a 20A / 240 VAC NEMA 6-20 will easily handle an overnight charge and be plenty for almost all situations. For the rare times it wont, a trip to the local CCS DC charger would work.

 

[Lainey]

The guy quoted upgrading the service at about $4500, so I'm a bit underwhelmed by that idea.

Yeah no go on that. I'd do the 30amp and not worry. The time difference likely will not be of a concern.

 

[moff1959]

So, now I'm talking to electricians and a sticking point has come up:

My house has 100amp service, total. The main panel is 100amps!

Electrician told me that a 50amp circuit for the EVSE would create a fire hazard, since that would leave only 30amps for the rest of the house (using an 80% rule). He's recommending I only get a 30amp circuit.

Doesn't that mean my EVSE would max out at 24amps? For the SE, we're talking about 77% of the capacity of the car to take in the electricity, so might that linearly increase my recharge time by about 30%?

Yes that would be my advice stay with in your state electrical code and set the Mini charge rate to a lower current (amps) setting at the CID, it is still going to be quicker than the EVSE supplied by Mini.

 

[quietlyspinach]

I'm in a similar situation; I have an existing 30A dryer plug that I would like to run an EVSE off of. I'm thinking 16A, 20A or 24A would be safe. The cheapest, UL-listed adapter I've found is the Webasto TurboPlug 240V for $174. It plugs into a NEMA 6-20 outlet, so I'd still need to get an adapter:

https://store.evsolutions.com/turbocord-240v-plug-in-ev-charger-p51.aspx

Next up is an Amazing-E (made by ClipperCreek) that also does 16A for $329, but it uses a NEMA 14-30 plug:

https://store.amazing-e.com/ev-charging-stations/level-2-charging-station-16-amp-amazinge

ClipperCreek also has a 20A and 24A for significantly more $$:

$485 for 20A
https://store.clippercreek.com/level2/level2-20-to-32/lcs-25p-nema-14-30

$515 for 24A
https://store.clippercreek.com/lcs-30p-nema-14-30

If my math is right,
16A is 3840 Watts = 8 hours to full
20A is 4800 Watts = 7 hours to full
24A is 5760 Watts = 6 hours to full

Is there any reason to spend the extra money on the 24A? Can the MINI be set to charge at a slower rate if needed? The EVSE's do not appear to have any ability to change the reported available max charge available, so this would all have to be done on the car side. I downloaded the 2021 manual for the MINI and it talks about limiting the charge rate at 120V but nothing about what the settings "Max", "Reduced" and "Low" correspond to when connected to a 240V Level 2 EVSE.

 

[moff1959]

I'm in a similar situation; I have an existing 30A dryer plug that I would like to run an EVSE off of. I'm thinking 16A, 20A or 24A would be safe. The cheapest, UL-listed adapter I've found is the Webasto TurboPlug 240V for $174. It plugs into a NEMA 6-20 outlet, so I'd still need to get an adapter:

https://store.evsolutions.com/turbocord-240v-plug-in-ev-charger-p51.aspx

Next up is an Amazing-E (made by ClipperCreek) that also does 16A for $329, but it uses a NEMA 14-30 plug:

https://store.amazing-e.com/ev-charging-stations/level-2-charging-station-16-amp-amazinge

ClipperCreek also has a 20A and 24A for significantly more $$:

$485 for 20A
https://store.clippercreek.com/level2/level2-20-to-32/lcs-25p-nema-14-30

$515 for 24A
https://store.clippercreek.com/lcs-30p-nema-14-30

If my math is right,
16A is 3840 Watts = 8 hours to full
20A is 4800 Watts = 7 hours to full
24A is 5760 Watts = 6 hours to full

Is there any reason to spend the extra money on the 24A? Can the MINI be set to charge at a slower rate if needed? The EVSE's do not appear to have any ability to change the reported available max charge available, so this would all have to be done on the car side. I downloaded the 2021 manual for the MINI and it talks about limiting the charge rate at 120V but nothing about what the settings "Max", "Reduced" and "Low" correspond to when connected to a 240V Level 2 EVSE.

Yes it does for both 120v and 240v I had to turn mine up from the factory set level which was the lowest setting its basically low, medium and high rate at which it will suck out the amps from your wall box.

 

[quietlyspinach]

Yes it does for both 120v and 240v I had to turn mine up from the factory set level which was the lowest setting its basically low, medium and high rate at which it will suck out the amps from your wall box.

Do you know what the actual amps are for Low Medium and High?

 

[moff1959]

Do you know what the actual amps are for Low Medium and High?

I don't remember the actual number it may have been a Kw rate setting for the on board charger, I would have to go into the menu on the vehicle and see how its listed.

 

[Lainey]

Do you know what the actual amps are for Low Medium and High?

My Charge Point gave me 3.8kwh vs 7.4 on the low setting. So roughly half.

 

[insightman]

Keep in mind too that the cars do not charge full level towards the end so it could make it harder to guess full 100% charge times.

Disclaimer: I'm not an electrician, so my calculations--and my charge-tapering expectations--may be bogus.

My MINI connected to a 50-kW DCFC charging station slows down charging when it's 80% full. However, it doesn't taper off to the AC Level 2 max of 7.4 kW until very near the end of charging. This anecdotal non-scientific evidence leads me to believe that charging at 20 Amps (20 A x 240 V = 4.8 kW) would continue, untapered, until the battery was fully charged. Basing my estimate on that constant charging rate, you would go from 0 charge (which no one does) to fully charged in 6 hours (28.9 kWh/4.8 kW).

Is there a chance your family may acquire a second electric car? That would possibly increase your motivation to upgrade your electrical service.

 

[fizzit]

Yeah I'd say don't worry about the upgrade unless you're planning to have multiple EVs in the near future. In 2.5 years of EV ownership I've only had one time my 3.3kW charger wasn't fast enough so I needed to go to a nearby DCFC. Your situation could be different though if you have a long commute.

 

[Lainey]

Disclaimer: I'm not an electrician, so my calculations--and my charge-tapering expectations--may be bogus.

My MINI connected to a 50-kW DCFC charging station slows down charging when it's 80% full. However, it doesn't taper off to the AC Level 2 max of 7.4 kW until very near the end of charging. This anecdotal non-scientific evidence leads me to believe that charging at 20 Amps (20 A x 240 V = 4.8 kW) would continue, untapered, until the battery was fully charged. Basing my estimate on that constant charging rate, you would go from 0 charge (which no one does) to fully charged in 6 hours (28.9 kWh/4.8 kW).

Is there a chance your family may acquire a second electric car? That would possibly increase your motivation to upgrade your electrical service.

As an FYI before I ramped it up to max, my car did taper off from the 3.8kwh for the last 10 mins or so.

 

[bldxyz]

Is there a chance your family may acquire a second electric car? That would possibly increase your motivation to upgrade your electrical service.

In all likelihood, we won't buy a second electric until ... 2029 or 2030, since that's when my kids should be done with college(!)

Yeah I'd say don't worry about the upgrade unless you're planning to have multiple EVs in the near future. In 2.5 years of EV ownership I've only had one time my 3.3kW charger wasn't fast enough so I needed to go to a nearby DCFC. Your situation could be different though if you have a long commute.

This is exactly the kind of thing that is going through my mind! No, my commute is not long, and should the worst thing happen (me having to take a job 40 miles away), I imagine I would be recharging at work each day that I drove. As it will stand, when the pandemic ceases and I regularly drive to an office again, I figure something under 20 miles a day. So it seems a bit much for me to get the most infrastructure I can when I cannot think of a use case where 4.5 hours is going to make a meaningful difference over 6 or even 7 hours for a full recharge. What is likely more meaningful is the DC/Fast Charging speed at commercial charging stations.

 

[F14Scott]

Data point:
My job is 32 miles away, and the worst I have arrived home with, after:

a 40 degree F day
80 MPH on the highway
foot to the floor acceleration from all lights and stop signs, and
climate on Auto at 68 degrees
in Standard (not Green or G+)

was 31% SOC.

Install the 30 Amp (or even the 20 Amp) and don't give it another thought. My SE and Tesla M3 share a 240V, 60 Amp breaker, but if my panel hadn't the overhead, I'm convinced they would be well served sharing even 20 Amps.

240V, 20 Amps delivers about 200 miles of range in a12 hour, overnight shift. That's way more driving than my wife and I do in a day, on average.

 

[quietlyspinach]

As an FYI before I ramped it up to max, my car did taper off from the 3.8kwh for the last 10 mins or so.

Thanks, that's really helpful to know! My initial inclination is to just get the 16A EVSE from Webasto and upgrade later if I find I really need it.

 

[Puppethead]

Install the 30 Amp (or even the 20 Amp) and don't give it another thought.

I concur, go with this. If you do ever decide to get a second EV, that's when you'd spring for the service upgrade. Your goal should be to get a full charge overnight. From my experience 1.2 kW (120 V 10 A) took more than 12 hours, but 4.8 kW (240 V at 20 A) will be plenty for overnight charging.

 

[Texas22Step]

I concur, go with this. If you do ever decide to get a second EV, that's when you'd spring for the service upgrade. Your goal should be to get a full charge overnight. From my experience 1.2 kW (120 V 10 A) took more than 12 hours, but 4.8 kW (240 V at 20 A) will be plenty for overnight charging.

And, get a second (or third) quote on the service upgrade. The quote in hand of $4,500 sounds like a lot to me, especially since most residential meters are able to supply up to 300 amps to a home.

 

[GvilleGuy]

And, get a second (or third) quote on the service upgrade. The quote in hand of $4,500 sounds like a lot to me, especially since most residential meters are able to supply up to 300 amps to a home.

Agree - I got a very wide spread of quotes on 50-amp circuit installation.