EV Charging

[nakman]

We have a 2018 Nissan Leaf with a 40kWh battery. So far so good. Yesterday it was down to about 20% capacity, and I charged it up to 100%. I got a new Level 2 charge cable that shows me power usage, status, etc. also allows me to select from 2amps to 32 amps, and a few stops inbetween- it's hooked to a 40amp breaker so I went for full send, the highest I saw on the readout was 29 amps. During the last hour of the charge the amp consumption tapered down, here it is towards the start of the decline. Here's the cable: https://www.amazon.com/dp/B09HGTWSK9?psc=1&ref=ppx_yo2_dt_b_product_details

Took about an hour for the amps to drop to 0, then the charge was complete. Also I noticed the temperature got up to 47 C at one point, started at 11 C. All just interesting data really, here's the end screen:

I like how the math on the battery kinda adds up here.. with the presumption that if it were to be completely dead, and also have 100% of its life, that it would take 40kWh of power to charge it completely. Yesterday it took 29.2kWh for 80%... close enough.

Also yesterday, the solar system produced 31.5kWh of power.

Hardly a "free tank of gas," given the investment I make to the infastructure here... but hey maybe in a few years it'll start to feel that way. I am curious how you other EV guys juice up your rides- do you do it at night, and at low amps, or do it in the day at higher amps, etc., and if there's a difference there? Also I have overheard a few of you say you don't go to 100%? And dumb question but just want to affirm my power consumption would be the same, if I were to drop the amperage of the charger, it would just take longer correct? So only reason to maybe drop it would be if I didn't need the car for 12 hours instead of 5, and electricity was going to be cheaper later?

 

[gungriffin]

I didn't realize that you had a Leaf. I don't have an electric vehicle yet, but I look forward to seeing what people say. I have looked closely at getting a Leaf several times before. 29A of 240v is a pretty good amount of juice. That is impressive that a $250 charger can do that now.

Did you ever switch over to a Time of Use electric plan with Xcel after installing solar? If so, during off peak from 7pm to about 1pm the following day, you pay less for any electricity used. Electricity is super expensive during peak hours at 3-7pm under that plan too. That would shape when I set the car to charge.

Just a thought- many of the Leafs allow for two way charging. This is an easy way to get a battery backup for your solar system in the event the power goes out. You just need to switch to a 2 way charger.

 

[J1000]

I had Time of Use with Xcel when I had my leaf but I don't think it was worth it and I went back shortly after. With solar it probably is worth it because during peak you are making your own power. I found that when the car was home it was plugged in and charging no matter the time of day or what we had planned. That way we could drive it as much as possible and keep miles off our gas cars. After owning an EV for a little while you will probably realize that you want the fastest charging you can get to maximize the usefulness of the car. It's so convenient to just hit a gas station I didn't realize how inconvenient it would be to not have that opportunity.

Also I say charge to 100% and use the car. Old LEAFs have very little difference in degredation if the owners charged to 80% or 100%, the calendar aging is worse. So those owners gipped themselves out of the range every day for little to no benefit in the long run.

 

[nakman]

I haven't looked at Time of Use, interesting. I am still waiting on my next bill from Xcel that should be the first to actually net out my solar production, and then my next course of action is going to be asking them for credit for all the electricity I produced beforehand. Not going to make any other changes until I can get to that point.

But yes so far it seems like the wife comes home and plugs in the car. She can go to work and back 3x on one charge but feels better if she only goes twice... plus that way if she has to make other stops, etc., there's no anxiety about that, plus I think life's too short to ration heat, not drive fast, etc. And yeah exactly Jimmy the whole point is to have a charged car available to drive, to keep the miles off the other gas vehicles. This is our first EV and seemed like a good way to get into the game. Most of our charging has happened at night though, yesterday was the first big charge during the day that felt like it was more or less fueled by the sun.

 

[rover67]

Have you looked to see if there are any free places to charge near her work? There are near my office so it makes the commute to and fro free essentially.

 

[nakman]

She has looked, they don't have anything at least not in the garage where she parks. And the parking lot is full of Teslas, none of them charging, so you'd think if there was a way for someone to be charging they would be.

 

[mcgaskins]

While this sort of started as an experiment to see if it would work, we exclusively charge off a normal household 120v outlet (11amps usually) for our Model Y, and it picks up about 5 miles of range per hour except for a couple days when it was hovering around 0 degrees (dropped to only about 2 miles of range per hour). We will need a 240v charger installed for the Rivian however as it's more power hungry and 120v doesn't cut it, and the battery pack in the R1S is 135kw vs only 75kw for the Y.

 

[nakman]

@mcgaskins Matt will the Rivian not charge at all with a 110 plug? Or is it just super slow?

 

[mcgaskins]

@mcgaskins Matt will the Rivian not charge at all with a 110 plug? Or is it just super slow?

It won’t really charge on 110v at all unfortunately and requires 220/240v at home to make sense.

 

[DaveInDenver]

@mcgaskins Matt will the Rivian not charge at all with a 110 plug? Or is it just super slow?

Their FAQ indicates 120V charging is possible.



Their EPA certification seems to indicate it can charge at 1,440 watts on 120V.



And that agrees with their portable charger manual.



So, yeah, pretty slow. The "mega" pack is 180 kW-hr for 400 miles. So it'll return the whole pack in 138 hours or about 2.9 miles per hour charged. Their other pack sizes are 105 kW-hr (260 miles) and 135 kW-hr (314 miles). The math is consistent at ~3 miles per hour on the 120V charger.

 

[mcgaskins]

Their FAQ indicates 120V charging is possible.

View attachment 102501

Their EPA certification seems to indicate it can charge at 1,440 watts on 120V.

View attachment 102503

And that agrees with their portable charger manual.

View attachment 102502

So, yeah, pretty slow. The "mega" pack is 180 kW-hr for 400 miles. So it'll return the whole pack in 138 hours or about 2.9 miles per hour charged. Their other pack sizes are 105 kW-hr (260 miles) and 135 kW-hr (314 miles). The math is consistent at ~3 miles per hour on the 120V charger.

I understand what the math says, but I'm referring to actual experience

 

[DaveInDenver]

@mcgaskins Matt will the Rivian not charge at all with a 110 plug? Or is it just super slow?

It won’t really charge on 110v at all unfortunately and requires 220/240v at home to make sense.

I understand what the math says, but I'm referring to actual experience

Just seemed like your statements were inconclusive so I looked into it. Either it will or it will not charge plugged into a 120V outlet. Rivian's publications say it will and their numbers validate the super slow assumption.

Does your actual experience dispute these? If so what is incorrect? Are they optimistic on 1.3 kW returned or something like that?

It seems loose marketing b.s. like this is a problem with EVs. Especially if you're trying to sell to people taking one to places away from home. Like, I dunno, you might have to plug into a friends outside outlet they normally use for hedge trimmers or need to use a portable generator in the backcountry in a pinch. It would be nice to be honest with a buyer about how long they're gonna have to sleep on a buddy's couch before they can drive home.

 

[mcgaskins]

Just seemed like your statements were inconclusive so I looked into it. Either it will or it will not charge plugged into a 120V outlet. Rivian's publications say it will and their numbers validate the super slow assumption.

Does your actual experience dispute these? If so what is incorrect? Are they optimistic on 1.3 kW returned or something like that?

It seems loose marketing b.s. like this is a problem with EVs. Especially if you're trying to sell to people taking one to places away from home. Like, I dunno, you might have to plug into a friends outside outlet they normally use for hedge trimmers or need to use a portable generator in the backcountry in a pinch. It would be nice to be honest with a buyer about how long they're gonna have to sleep on a buddy's couch before they can drive home.

All I'm trying to say is in my personal experience, plugging into 120v doesn't do enough to make it worthwhile. I've only done it when it's super cold outside, and I was getting a bit less than 3 miles of range per hour. But, the Tesla which normally gets ~5 miles of range per hour slows to about ~2 miles of range per hour under the same below freezing conditions, so consider a similar reduction. Like I mentioned above, you want 240v for this vehicle just like any of the huge battery pack EVs coming - Hummer, Lightning, Silverado, etc.

 

[rover67]

While this sort of started as an experiment to see if it would work, we exclusively charge off a normal household 120v outlet (11amps usually) for our Model Y, and it picks up about 5 miles of range per hour except for a couple days when it was hovering around 0 degrees (dropped to only about 2 miles of range per hour). We will need a 240v charger installed for the Rivian however as it's more power hungry and 120v doesn't cut it, and the battery pack in the R1S is 135kw vs only 75kw for the Y.

What charger will you install for the Rivian? All I can seem to find are 40a chargers (juice box and charge point). Are there ~50a chargers like the Tesla wall chargers available? It seems like they are making 40a somewhat of a max because they want them to be compatible with the 50a welder/rv plugs but I intend to hardwire with appropriate gauge wire and conduit.

This will be for a shared charge spot so I’d like it to be as fast as possible.maybe the last 10a isn’t a big deal. I plan to install two chargers anyways.

 

[gungriffin]

What charger will you install for the Rivian? All I can seem to find are 40a chargers (juice box and charge point). Are there ~50a chargers like the Tesla wall chargers available? It seems like they are making 40a somewhat of a max because they want them to be compatible with the 50a welder/rv plugs but I intend to hardwire with appropriate gauge wire and conduit.

This will be for a shared charge spot so I’d like it to be as fast as possible.maybe the last 10a isn’t a big deal. I plan to install two chargers anyways.

If you search "level 2 home charger", you will find chargers beyond 40a. I don't have an electric car, but I just remember that is what Nissan/Tesla used to call their professionally installed chargers.

For example:

Connected EV chargers for home | Enphase

store.clippercreek.com

 

[gungriffin]

@mcgaskins will the Rivian support bidirectional charging?

 

[rover67]

Oh that helps a lot. My search fu is weak. Those keywords return a lot more. FWIW looks like the Rivian can accept 48 amps (11.5kw) like the Tesla so that’s the practical upper limit. Also looks like they all come in a 48a flavor.

 

[nakman]

Hey I'm trying to understand the Xcel incentives for using one of their plugs. I have a friend with a Leaf who swears up and down that he's saving a bunch of money, being on their EV Accelerate at Home program.. https://ev.xcelenergy.com/ev-accelerate-at-home-co

I can't seem to make any sense of it- I pay them $770 up front, and also $6.68 per month, for the privilege of being able to charge our car between midnight and 06:00, when the rates are lower. that just doesn't seem like an incentive... the Leaf already has a way to program it to only charge between midnight and 06:00, using any old cord... am I missing something here?

There are other incentives as well, but I'm not sure I'm ready to program my laundry for overnight runs to get on the Time of Day whole home nonesense.. https://ev.xcelenergy.com/ev-charging-programs

 

[DaveInDenver]

Are they offering a uniquely lower rate or perhaps some sort of credit or rebate for installing their smart charger? Otherwise you're on target that you can adjust charging to take advantage of the lower rates yourself and not hand over that decision.

 

[nakman]

Are they offering a uniquely lower rate or perhaps some sort of credit or rebate for installing their smart charger? Otherwise you're on target that you can adjust charging to take advantage of the lower rates yourself and not hand over that decision.

I can't find anywhere that says it's a lower rate, other than what they'd offer anyone for using power on an off-peak time period. I found mention of a $50 annual rebate, but then I discovered I was in Minnesota not Colorado on the website... didn't see that for Colorado. The rebate isn't even close to a break-even of their monthly fee and/or initial investment.

But it just doesn't add up that this would be a total scam- why would any sane person buy a $800 cord just to do what they could have programmed their car to do anyway? People can't be that naive.. I still think I'm the one who's missing something here.