dvu
Posts: 22
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Leaf Number: 414294
Location: SF Bay Area

Anyone charging 2 EV's using 100amps mains?

Mon May 22, 2017 12:17 pm

When we purchased the Leaf, it was a place holder for a model 3 but the Leaf has served its purposed pretty well so we're going to keep in. However, having the Tesla we'll need to add a 2nd 40amp 240 to the house. Our mains is only 100amp.

Will I need to upgrade my service panel to a 200 amps?

Our stove is electric and so is our dryer, I can't imagine having all that running at the same time along with charging 2 EV a good thing on our old house service panel of 100 amps.

wwhitney
Posts: 650
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Location: Berkeley, CA

Re: Anyone charging 2 EV's using 100amps mains?

Mon May 22, 2017 12:57 pm

It seems very likely that a load calculation for a house with (2) 240V 40A EVSE circuits would exceed 100A, in which case you would need to upgrade your electrical service. An alternative would be to use two EVSEs designed to share a single 40A circuit, such as these:

https://store.clippercreek.com/Share2-HCS-40-Bundle

There may be other brands available.

Cheers, Wayne

Graffi
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Leaf Number: 414757
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Re: Anyone charging 2 EV's using 100amps mains?

Mon May 22, 2017 1:37 pm

We have an AV 30 amp EVSE that was installed within two weeks of getting the Leaf. We almost always have the Leaf set to charge to 80% so we plug it in as soon as we get home. In less than one hour it i ready to go again. Once every week or so we charge it to 100% so the battery pack gets to balance.

For the Tesla Model S 75D we leave it set for 90% while on trips, then set it for 50% while at home. However we only plug it into the same EVSE when the charge gets very low. This is done overnight after the Leaf is already at 80%. So far now conflict.

However, we do have a 50 amp breaker unused on our 200 amp panel, left over from a hot tub that was removed when we built a patio room where the hot tub was located. I purchased a 14-50 outlet, a wall box, and 7 feet of 6AWG just in case we ever did need to charge both at the same time. I expect it will only be used a couple of times each year, if that. However, it was worth the cost and my labor to have it available for those rare occasions when it will be needed. While I was at it, I also added a 20 amp 120 volt GFI outlet tied to one side of the 14-50 so at least we would have 120 volts available on that side of the garage. And we know to not use the 120 volt outlet if we plug in the Tesla.

Not knowing your situation I would still think that a 200 amp service would be call for. You can get away without it, just make sure you only charge one EV at a time, and not while cooking with more than one burner and running the electric close dryer at the same time.
2013 SL Metalic Slate - We LOVE our Leaf
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2017 Tesla S 75D Pearl White
Delivered 5/16/17 @ 900 mi
Tesla Model 3 on order awaiting 200+ mile range Nissan Leaf

rmay635703
Posts: 345
Joined: Wed Jan 19, 2011 7:43 pm

Re: Anyone charging 2 EV's using 100amps mains?

Mon May 22, 2017 2:26 pm

dvu wrote:When we purchased the Leaf, it was a place holder for a model 3 but the Leaf has served its purposed pretty well so we're going to keep in. However, having the Tesla we'll need to add a 2nd 40amp 240 to the house. Our mains is only 100amp.

Will I need to upgrade my service panel to a 200 amps?

Our stove is electric and so is our dryer, I can't imagine having all that running at the same time along with charging 2 EV a good thing on our old house service panel of 100 amps.


If you are willing to accept the EV charge rate varying, there is a modern version of the so called load minder available and meets code, it affectively is upstream and shared off of your panels available load, meaning if you are charging and turn on your oven one of your EVs will cycle between charging and not charging while it's in use <or> the more advanced solution reduces its rate to what's left over.

There was a thread with a Canadian guy who could not upgrade his home electric that had a link to one.

Depending on how expensive a panel is it might be cheaper to just use what you have with a modern load minder.

My guess is your oven doesn't run 8 hours a day nor does your dryer so you are likely safe to let your ev(s) charge a little slower the short time you are running both.

A link to such a device was posted in another thread

dvu
Posts: 22
Joined: Sun Nov 20, 2016 12:04 pm
Delivery Date: 26 Nov 2016
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Location: SF Bay Area

Re: Anyone charging 2 EV's using 100amps mains?

Mon May 22, 2017 2:33 pm

Thanks guys, great options out there. It'll set us back between $3k to $5k for the service upgrade, With out Leaf, we haven't had the need to ever go below 20% of it's charge. I'd imagine it'll be the same with the Tesla. It'll also be very seldom that both will need to be charged from emptied together since I work at home and the leaf's is the wife's commuter of about 30 miles RT and charging is available at her work.

I like the shared EVSE idea for its simplicity since we already have a plug in place.

Just tried to search for the load minder but came up short. I'm a day one reserver, but probably won't see the M3 till the end of the year if I'm lucky, so I still have some time to decide.

sub3marathonman
Posts: 302
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Location: Bartow, FL

Re: Anyone charging 2 EV's using 100amps mains?

Mon May 22, 2017 3:10 pm

rmay635703 wrote:
dvu wrote: Our mains is only 100amp.

Will I need to upgrade my service panel to a 200 amps?

Our stove is electric and so is our dryer, I can't imagine having all that running at the same time along with charging 2 EV a good thing on our old house service panel of 100 amps.


If you are willing to accept the EV charge rate varying, there is a modern version of the so called load minder available and meets code, it affectively is upstream and shared off of your panels available load, meaning if you are charging and turn on your oven one of your EVs will cycle between charging and not charging while it's in use <or> the more advanced solution reduces its rate to what's left over.

There was a thread with a Canadian guy who could not upgrade his home electric that had a link to one.


I'm not sure if this is the thread rmay635703 was thinking of: http://www.mynissanleaf.com/viewtopic.php?f=27&t=23698&start=30, and he was in Alaska not Canada, but quoting from ermackey "New solution idea: Using a Samsung Smartthings Hub and a few Z-wave relays, I can put my Hot Water and two car chargers, on Z-wave "smart" switches. One of the new app features is the "Max Energy" app that turns off specific devices as KW consumption is reached. I could "tier" my appliances to operate on a priority tier ranking. AEON makes a energy monitor that works with Smartthings to utilize this feature." In that same thread, gshepherd's suggested the extremely energy efficient "condensing" dryer, and freed up a 240V breaker.

I was wondering too about converting the stove and/or the dryer to gas. I live in Florida, and everything here is electric too, but gas is so much nicer for cooking, and using electricity to turn into heat for a dryer seems almost criminal when the electricity could do so much more.

Another idea might be PV with or without a battery backup. That would be a way to get more out of sunny days, although with just a 100 amp panel it might require a line-side tap, which is less than optimum and power companies frown upon. But even if it was a small enough system and just use a 20 amp backfed breaker, it would help.

And, instead of a simple load calculation, it is possible to gather 30 days of real-world usage and use that for the calculations and still be code compliant. But you'll have to consult a very sharp electrician for that who really knows code.

Call me "thrifty," but I'd explore a lot of options before I'd pay $3K - $5K to upgrade the panel, even if the panel is considered low for modern homes.

Of course, you could do it the real simple way and just charge the LEAF at 120V when the Tesla needs topping off. It is a dilemma I'd love to have. :D

dvu
Posts: 22
Joined: Sun Nov 20, 2016 12:04 pm
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Re: Anyone charging 2 EV's using 100amps mains?

Mon May 22, 2017 3:23 pm

sub3marathonman wrote:
rmay635703 wrote:
dvu wrote: Our mains is only 100amp.

Will I need to upgrade my service panel to a 200 amps?

Our stove is electric and so is our dryer, I can't imagine having all that running at the same time along with charging 2 EV a good thing on our old house service panel of 100 amps.


If you are willing to accept the EV charge rate varying, there is a modern version of the so called load minder available and meets code, it affectively is upstream and shared off of your panels available load, meaning if you are charging and turn on your oven one of your EVs will cycle between charging and not charging while it's in use <or> the more advanced solution reduces its rate to what's left over.

There was a thread with a Canadian guy who could not upgrade his home electric that had a link to one.


I'm not sure if this is the thread rmay635703 was thinking of: http://www.mynissanleaf.com/viewtopic.php?f=27&t=23698&start=30, and he was in Alaska not Canada, but quoting from ermackey "New solution idea: Using a Samsung Smartthings Hub and a few Z-wave relays, I can put my Hot Water and two car chargers, on Z-wave "smart" switches. One of the new app features is the "Max Energy" app that turns off specific devices as KW consumption is reached. I could "tier" my appliances to operate on a priority tier ranking. AEON makes a energy monitor that works with Smartthings to utilize this feature." In that same thread, gshepherd's suggested the extremely energy efficient "condensing" dryer, and freed up a 240V breaker.

I was wondering too about converting the stove and/or the dryer to gas. I live in Florida, and everything here is electric too, but gas is so much nicer for cooking, and using electricity to turn into heat for a dryer seems almost criminal when the electricity could do so much more.

Another idea might be PV with or without a battery backup. That would be a way to get more out of sunny days, although with just a 100 amp panel it might require a line-side tap, which is less than optimum and power companies frown upon. But even if it was a small enough system and just use a 20 amp backfed breaker, it would help.

And, instead of a simple load calculation, it is possible to gather 30 days of real-world usage and use that for the calculations and still be code compliant. But you'll have to consult a very sharp electrician for that who really knows code.

Of course, you could do it the real simple way and just charge the LEAF at 120V when the Tesla needs topping off. It is a dilemma I'd love to have. :D


It's funny that the idea was to use a Zwave relay as I was just thinking the same thing. I don't use Smart Things but Vera, I already have energy monitoring of my "whole house" and already have a log of what my house uses on standby and how much it draws when A/C is running or when the stove is running. Great idea, I think a dry contact relay would do the trick just fine.

I know my house draws about 1kw at any given time due to all the servers and electronics I have running. My A/C typically add another 2000w to it and if I recall correctly, with 1 stove running, it'll spike up another 2000w.

I can easily add a dry contact relay to the EV charging circuit to shut it completely off when the house is drawing anything more than 2kw which is mostly midday in the summer when it's hotter than usual and during dinner time. But it'll still be charging through the night. If I take the stove out of the equation, it'll be easier since my HVAC is also tied to the home automation.

Since the A/C shuts on/off I'm just concern of the the reliability of the charger being on/off.

in case someone else is reading.... this should fit the bill nicely

https://www.amazon.com/Aeon-Labs-White-V3-26-AL001/dp/B00MBIRF5W

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jlv
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Re: Anyone charging 2 EV's using 100amps mains?

Tue May 23, 2017 7:30 am

dvu wrote:It'll also be very seldom that both will need to be charged from emptied together
Alternately, why complicate things? Just install 1 EVSE such that you can only plug in one of the EVs at any time. This avoid all the extra costs and complexity for a "very seldom" condition.
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rmay635703
Posts: 345
Joined: Wed Jan 19, 2011 7:43 pm

Re: Anyone charging 2 EV's using 100amps mains?

Tue May 23, 2017 10:34 am

jlv wrote:
dvu wrote:It'll also be very seldom that both will need to be charged from emptied together
Alternately, why complicate things? Just install 1 EVSE such that you can only plug in one of the EVs at any time. This avoid all the extra costs and complexity for a "very seldom" condition.

Yep and he could still plug the leaf into L1 in the mean time

aluminumwelder
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Re: Anyone charging 2 EV's using 100amps mains?

Sun May 28, 2017 7:35 am

$3000 to $5000 to upgrade a service panel that costs $150 is ridiculous. Several years ago I needed to upgrade the service panel in my home, I got quotes around $1100. that was a rip off too, would up hirinig friend electrician did it for $150.

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