New here with some stupid questions

[Mashedtators]

Also happy wife, happy life.

#endthread

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[Maybe Going EV]

Update: Spending 3 days with the Demo was interesting, and we learned a lot.
I was always a bit more skeptical than my wife, who really wanted me to look at it, a lot more than I would have without her encouragement. From the moment of my mentioning shopping for a new truck, to replace my 11 year old Ram, she was throwing around the Lightning name, and I didn't even know what it was.
Well now that we spent some time with a Lightning, I'm more impressed than I thought I would be. The power is smooth, and just always there, and seems effortless. It rides well, handles good, towed my enclosed trailer perfectly, which was admittedly empty so light, but a couple quads or snowmobiles isn't that much more weight, a couple thousand pounds with extra gas and some camping gear. We did extra driving, just to test it out, that we normally wouldn't have. Plugged into 120 volts it impressed us by how much that charged it. In a typical weeks use for us, 120 would charge between 3 and 4 times as much as we use. For trips it doesn't matter as we will be using charging stations then anyhow. If it was being driven 7 days a week, and sitting there in a parking lot every day unplugged, then yes a home 240 charging system would be great. We don't work anymore, retirement is wonderful. Normally it would only be unplugged 8 to 10 hours per week, and driven 120 to 140 kms a week. In reality we could leave it unplugged every 2nd week no problem. I didn't play with the settings much, but it seems from what I understand that it can be set to stop charging at any percentage of battery charge we desire, even if plugged in. So if we do buy one, which seems likely, we can set it to only charge to 70% for normal use, as ideally 50% is optimum for battery health. From 70% down to 50% would be more than we would ever use in a typical day of shopping, or church. Before any lengthy trips, set it to charge to 100%, so we leave with a full battery. The box is really small, i prefer an 8' box, and thought my 6.5' was small, but this is really tiny. But I have large trailers for larger items, and we can go to the garbage dump more often since it carries less. That front cubby hole could be handy at times it looks like, although we didn't actually put anything in it, just opened the hood for a look. The seats felt comfortable, and most controls easy to use. Overall it was a nice truck!

 

[PreservedSwine]

Generally speaking, 120 V would be adequate for my needs. I always have the option to drive ICE when needed.
I read somewhere that 240 V is more efficient. The efficiency difference can't be anywhere near the cost of running a 240 V line to my garage. But I did it anyway.
Regardless, I charge at the lowest setting (16 Amps) and only to 60% most days.

240v isn’t more efficient in terms of saving money for energy. It’s more efficient in moving electrons through smaller wire than the same amount of energy using 120v.
You still pay the same for the amount of energy consumed.

 

[CD4TNF]

You get it! You absolutely are right! Now you get why we've gone with the Lightning. The power, the convenience.

 

[tannerk89]

The garage attached to the house is I'll guess about 14' wide and 22' long, and just 8' tall ceilings. My Ram 1500 just barely fits in the door.
My truck shop is 40' wide, and 100' long, and 18 foot tall ceilings. It actually has 2 Blaze king wood stoves, but I usually only light 1, whichever is closest to where I'll be working.
I had 13 semi trucks, and 22 trailers at the peak of my business. Sold them all in 2022, and retired. Well i tried to retire, 2 long time friends who are owner operators of their own truck, asked me if I would drive for them every year when they take vacation time. Both were once employees of mine, and bought a truck and trailer from me when I was retiring. I'm happy to work 6 weeks a year for them, if its summer time. I don't chain up any more at -30, or care to drive in blinding snow storms anymore, i did that for 40 years.
Do love my 640 acres of privacy, and 310 acres is in hay, and the wife and i have 4 horses, 2 young and rideable, and our 2 old hay burners, we no longer ride but will live out their lives here on the farm. We sell the extra hay we grow, or trade it for beef/goat/chicken/eggs/milk. So yes I love where i live, about 5 kms of gravel road to the hwy, and then 25 kms of hwy to town, so a typical round trip for us to town is 60 kms. The wife rarely drives, but when she does will drive my pickup, since I didn't replace her suv she totalled 3 winters ago. She will not drive in the winter at all now, maybe drives 10 times a year total now, in summer. Which is why i consider it my pickup, even though we technically share a vehicle. At 500 kms a year she drives, its barely enough to call it driving.

What kind of trucks did you own? I work for Volvo Trucks as a Manufacturing Engineering Product Owner in the assembly plant, so I’m hoping you say Volvo or Mack!

 

[carys98]

240v isn’t more efficient in terms of saving money for energy. It’s more efficient in moving electrons through smaller wire than the same amount of energy using 120v.
You still pay the same for the amount of energy consumed.

There is about a 400W overhead anytime you are charging so you waste more energy while charging on level 1 since it takes much longer. If I charge 10 hours on level 1 to get the same charge I can get in 1 hour on level 2 I will waste 4 kWh versus only 0.4 kWh.

 

[PreservedSwine]

There is about a 400W overhead anytime you are charging so you waste more energy while charging on level 1 since it takes much longer. If I charge 10 hours on level 1 to get the same charge I can get in 1 hour on level 2 I will waste 4 kWh versus only 0.4 kWh.

That makes sense- thanks for the specifics

 

[John Becker]

There is about a 400W overhead anytime you are charging so you waste more energy while charging on level 1 since it takes much longer. If I charge 10 hours on level 1 to get the same charge I can get in 1 hour on level 2 I will waste 4 kWh versus only 0.4 kWh.

Source?
I'm not doubing you. I just want to further research this. I will need to rethink why I charge at 16 Amps rather than 40 Amps.
A slower charge is better for the battery but likely not material relative to 40 Amps. However, burning 400 Watts unnecessarily every night is troubling.

 

[Maquis]

Source?
I'm not doubing you. I just want to further research this. I will need to rethink why I charge at 16 Amps rather than 40 Amps.
A slower charge is better for the battery but likely not material relative to 40 Amps. However, burning 400 Watts unnecessarily every night is troubling.

There’s a thread on here where someone tested and plotted the charging efficiency at different rates. Faster charging is definitely more efficient, but the curve was pretty flat once you hit 40A, IIRC.

 

[TaxmanHog]

Source?
I'm not doubing you. I just want to further research this. I will need to rethink why I charge at 16 Amps rather than 40 Amps.
A slower charge is better for the battery but likely not material relative to 40 Amps. However, burning 400 Watts unnecessarily every night is troubling.

As Dave pointed out another member did a detailed comparison, I haven't looked for that thread yet, but I've noticed the same results. My driving routines each week are low enough that I only need to charge once a week, that also helps with minimizing overhead losses, typically about 9%

 

[carys98]

Source?
I'm not doubing you. I just want to further research this. I will need to rethink why I charge at 16 Amps rather than 40 Amps.
A slower charge is better for the battery but likely not material relative to 40 Amps. However, burning 400 Watts unnecessarily every night is troubling.

What I stated was a bit of a simplification. When you charge there are a number of modules that have to operate to manage the charging and the cooling system may need to turn on and off. The onboard charger isn’t 100% efficient so some energy is wasted there. The actual power draw will vary but based on what I’ve seen posted and what I’ve observed it seems to average about 400W. The other factor I didn’t take into account are the I squared R losses in the cable. As you increase the charge current the cable loss increases with the square of the current. At high currents the fixed loss becomes less significant and the cable loss increases. There is some ideal charge rate that optimizes the losses but that would require a differential equation and I haven’t solved one of those in a very long time.

My gut tells me that on Level 2 charging the difference between the optimum and the worst case loss is less than 2%. Every report of efficiency seems to be around 8 or 9% loss with people charging from 24A to 80A. It’s level 1 that is really inefficient because of the fixed loss and you only get half the power from a given current (12A at 120V has the same cable loss as 12A at 240V) at the lower voltage.

For your case of 16A vs 40A the cable loss is about 7W vs 40W so the fixed loss still dominates.

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