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mkennedy1996

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It's really exquisitly simple. Take the rated miles for your vehicle (314) and divide by 100 (3.14). That's the rated miles per percent of battery. Take the reciprocal of that (1/.314 = .32). Memorize that number (or write it on a sticky and put that in your truck). When at a charging station find out how many miles to the next one and multiply by that number e.g. 132 miles --> .3*132 + .02*132 =39.6 + 2.64 = 42%. That's how much charge you need to add. Note that in this case you can neglect the .02 and just rough it at .3*132 = 39.4 and then toss in a couple of extra percent. You would also toss in an extra couple of percent if you know the stretch or road you will be driving demands consumption a couple more percent that normal (because it's wet or there is a head wind or its uphill or you know this bit of road). Or just add 10% for "margin". Add 50% to your battery and go on your way.

I've posted this many times before elsewhere and often get responses such as "You call that simple?" I am aware that a frightening number of people are innumerate. This won't appeal to them.
Wow. That is one way to make a simple math problem much too complex and with less accuracy.

Adding a 10% fudge factor plus a few percent here and there is a lot of wiggle room.

With my formula, we arrive at the next charger within a few miles of our target range every time.
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mkennedy1996

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Exactly. Start the day with 100% charge from charging overnight, pull into DCFC with 5-10%, charge to ~70% and get back on the road and repeat is generally ideal for EV road trips.
I would disagree with this. Charging to 70%, when you only need to charge to 48% to get to the next charger, is a waste of your time and occupies a charger unnecessarily.

The ideal on a road trip is to only charge up the point that you need to reach the next charger. Any charging above that point in the charging curve is slow compared and wastes time and ties up a charger that may be needed by someone else.
 

Joints4Sale

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I would disagree with this. Charging to 70%, when you only need to charge to 48% to get to the next charger, is a waste of your time and occupies a charger unnecessarily.

The ideal on a road trip is to only charge up the point that you need to reach the next charger. Any charging above that point in the charging curve is slow compared and wastes time and ties up a charger that may be needed by someone else.
I would guess that Branden is referring to using a level 2 charger(At a hotel or at home to charge to 100% overnight) and then hitting a level 3 DCFC station for your second and subsequent charges(to enough range to hit the next DCFC to stay in the peak charging speed) on a road trip.

I fully agree with this charging strategy.
 

SeaGeo

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I would disagree with this. Charging to 70%, when you only need to charge to 48% to get to the next charger, is a waste of your time and occupies a charger unnecessarily.

The ideal on a road trip is to only charge up the point that you need to reach the next charger. Any charging above that point in the charging curve is slow compared and wastes time and ties up a charger that may be needed by someone else.
He's just making a general statement to avoid where fast charging most cars starts to become not-so-fast.
 

branden

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I would guess that Branden is referring to using a level 2 charger(At a hotel or at home to charge to 100% overnight) and then hitting a level 3 DCFC station for your second and subsequent charges(to enough range to hit the next DCFC to stay in the peak charging speed) on a road trip.

I fully agree with this charging strategy.
Precisely.
 

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Franksmartin

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Well Rivian was right about 140 miles in 20 minutes, they just didnā€™t mention what you get in the second 20 minutes.
 

ads75

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Curious. How many times a year do you guys drive more than 250 miles in a day?
Although I agree with your point, I don't want to spend 40 minutes at a charger on the days I do. At least from this video I know I can expect to.
 

LaunchGreen

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Although I agree with your point, I don't want to spend 40 minutes at a charger on the days I do. At least from this video I know I can expect to.
Not sure I had a point other than wondering if I was part of a minority or if it was the majority where this wasnā€™t a major concern.

The answer for me, by the way, is 4 days in the last 11 years (excluding rental cars).
 

r1t_kev

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Although I agree with your point, I don't want to spend 40 minutes at a charger on the days I do. At least from this video I know I can expect to.
Using the numbers from this video, starting the day at 80% SoC, you'd have 215 miles of range. Tommy pulled into the charger at 20% SoC with 60 miles of range left. After about 20 minutes at this charger, he could have left in the mid-50s% SoC and 135ish miles of range. Not saying that's super fast, but I don't think it's necessary to sit at a DCFC for 40 minutes if you don't need to. On a 250 mile day, one 20 minute stop would give you enough for a round-trip, with a pretty big margin, even leaving your house at 80%.
 
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JayinNJ

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Very disappointing results and would have liked to see 0-100%.

Peak speed was 151 kw. Took 41 min from 20-80%. The curve is not very impressive either with a big taper by 80% all the way down to 51 kw.

The range in the cold weather seems decent but we donā€™t know where they were driving and at what speed. Showed 215 miles at 80%.

The taper looked fine. I just would have expected it to hit higher levels till about 40% and then follow this curve. Could very well be a combination of temperature and the specific charger. It held the ~150kW for so long that is seems suspicious. It will probably take a few more attempts at different locations to know the real potential.
 

ads75

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Not sure I had a point other than wondering if I was part of a minority or if it was the majority where this wasnā€™t a major concern.

The answer for me, by the way, is 4 days in the last 11 years (excluding rental cars).
I probably average about 1-2 trips a year where I drive more than 250 miles to a destination. And then home, a few days later, where vacation houses sometimes have outdoor outlets, and sometimes may not. I've been playing with A Better Route Planner, to see what my potential charge times/destinations are. I realize, if I am stopping, it is going to probably be, 20-30 minutes, each time, at least until I get comfortable with a charging network. But I also drive 125 miles to a destination, and then home in a day (about 250 miles round trip, with an expected range of about 275 miles max for my desired R1T configuration, figuring in wheel range loss, and highway travel) fairly frequently, and the all terrain range hit and highway range hit, will impact my plans.
 

SANZC02

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Although I agree with your point, I don't want to spend 40 minutes at a charger on the days I do. At least from this video I know I can expect to.
Itā€™s funny, Iā€™m a point A to point B traveler as well, thought I would hate stopping to charge. When we travel in the Tesla, Iā€™ve just been coordinating meals and bathroom breaks with the charge stops and it really has been nowhere near what I was dreading.
 

Craigins

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Curious. How many times a year do you guys drive more than 250 miles in a day?
For me:
Precovid 5-6 trips a year.
Post covid 12-13.

360 miles each way. Only 1 50kw charger in the second half of the trip. Going to be really risky until the 2 planned RAN stations are built.

Tempted to not trade in my Ram at this point.
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