Questions about charging on a long road trip

[Kamban]

First post here

I am going to buy a Tesla SR+ in a week's time. LR-RWD was my choice but not available. I plan to take a 600 mile trip a month later.

I used a better route planner with Tesla superchargers and it gave me these first 3 charging options, when starting out at 90% charge from home
At 09 miles battery at 39% charge to 75% in 15 mins for $3.46
Next charge 121 miles later when battery is 10% and charge to 52% in 14 mins for $6.21
Next in 77 miles when charge is 10% and charge to 60% in 17 mins for $7.40

My questions are
1. I do not want to charge the first charge to only 75% and run it down to 10% for the 2nd charge since that leg will be climbing part of Appalachian mountains where battery consumption can be higher than predicted. So if I play it safe and charge to 90% at the first super charger instead of 75% can I expect to have 25% charge left in my natter when I arrive at 2nd supercharger instead of 10%. In other words is it linear that the battery power and between 10 and 20 % is almost the same as between 50 and 60% or 80 and 90%.
2. Why is the charging between 39 and 75% (36%) in the first leg only $3.46 but between 10 and 52% (42%) in the 2nd supercharger quite a bit expensive at $6.21. Are KWH different between different battery percentages?

Thanks

 

[Rottenapplr]

May be the area where you are charging to has different electric rates???

 

[Evbwcaer]

In response to question #1, yes the consumption is linear. It is not like some gas cars where the fuel needle barely moves for 100 miles then starts to dive. The only exception to this might be in the 0-5% window in cold weather.

I’d start out with a 100% charge, or very close to it, if you are able to leave as soon as that high state of charge is achieved.

Have a good trip.

 

[TexasGator]

Abetterrouteplanner takes elevation changes into account - but yes if you want more margin when arriving at the supercharger you just charge to a higher percentage at the first stop.

there is a setting in the detailed settings where you can adjust that "arriving charge %" up - i believe 10% is the default - as most folks with more EV experience want as much time as possible in the steepest portion of the charging curve (10% - 80%

 

[M3BlueGeorgia]

Use abetterrouteplanner.com to plan your trip.
It'll give you an optimum route and show you the Superchargers you'll be skipping.

No reason to charge above 90%, unless there is some immediate benefit to it.

Once you start the drive, have the trip plan in mind when you punch the destination into the Tesla Navigator. You may opt to override its selections and target different Superchargers.

In general, try to arrive at a Supercharger with 15% - 20% charge, and then only charge enough to get to the next stop with the same target charge. Once you get confidence, you may change that to 8% - 15%, especially if you are passing an intermediate Supercharge you plan to skip (but might use for a top-up).

Because the Supercharger network was laid out originally to service Model S with 60 and 75 batteries, you should find there's enough stations at a reasonable distance for your trip.

 

[sootless]

A better route planner will optimize your charges to take the least amount of time. The charge rate starts to drop off at 40-50% quite significantly. ABRP is quite good at estimating but can be off if you run into rain or a headwind or temperatures are lower than expected. 10% is probably fine. Your consumption would need to be 13% more than what ABRP is expecting for you to completely deplete the battery. There is no harm charging to 85% or more at that first stop except for the time penalty. It sounds like it will save you some money too. You can also set your minimum arrival percentage in ABRP. If you aren't yet comfortable with 10% then increase it to 15% or more. As you use ABRP you will get more comfortable with it. I now have no issues with 8-10% battery arrival but also do keep an eye on the weather. I find it to be at most out 2 or 3%. It may differ with your setup. A real cool thing with ABRP is you can drive with it on the browser of your car and it will graph your actual vs planned. This takes a lot of the range anxiety out of the experience. Have a great trip!

 

[darth_vad3r]

The price difference could be due to Superchargers that bill per minute instead of per kWh ... since it's slower to charge at higher state of charge (SoC) then it will take longer and cost more to charge at those superchargers even if you are adding the same amount of energy to the battery.

Also what reference speed did you punch into ABRP's settings? You should only use the default 100% if you actually follow the speed limit. I crank mine up to 125 or 128% because I drive fast, but apparently our limits are a bit lower than in the US. Adjust according to your driving style to get more accurate estimates.

Speed kills battery!

 

[KenC]

First post here

I am going to buy a Tesla SR+ in a week's time. LR-RWD was my choice but not available. I plan to take a 600 mile trip a month later.

I used a better route planner with Tesla superchargers and it gave me these first 3 charging options, when starting out at 90% charge from home
At 09 miles battery at 39% charge to 75% in 15 mins for $3.46
Next charge 121 miles later when battery is 10% and charge to 52% in 14 mins for $6.21
Next in 77 miles when charge is 10% and charge to 60% in 17 mins for $7.40

My questions are
1. I do not want to charge the first charge to only 75% and run it down to 10% for the 2nd charge since that leg will be climbing part of Appalachian mountains where battery consumption can be higher than predicted. So if I play it safe and charge to 90% at the first super charger instead of 75% can I expect to have 25% charge left in my natter when I arrive at 2nd supercharger instead of 10%. In other words is it linear that the battery power and between 10 and 20 % is almost the same as between 50 and 60% or 80 and 90%.
2. Why is the charging between 39 and 75% (36%) in the first leg only $3.46 but between 10 and 52% (42%) in the 2nd supercharger quite a bit expensive at $6.21. Are KWH different between different battery percentages?

Thanks

Start with 100% at home, and set your stop %age to 15%, not 10%, that'll give you a little more cushion. Abetterrouteplanner takes elevation into account.

The different cost is likely due to a different cost structure in a different State.

 

[Kamban]

Thanks everyone for your replies.

I did not realize that superchargers charge differently based on local electricity rates. I thought that Tesla went to cost per KWH for all chargers to make it more fair.

I left it at default settings of 100% of speed with max speed of 80 miles per hour. Good idea of charging to 95% or so at start at home and charging to higher percentages in states with lower supercharger rates and keeping minimum arrival charge at 15%..

I think that my SR+ does not have usable browser if I understand correctly what I have read. Maybe I have to depend on my cellphone, which is a bit spotty in the mountains.

 

[gavine]

Use the trip tab in the energy app. It graphically shows what percentage of battery you will have at your destination and gives you a comfort level. It is also more accurate than the battery meter.

 

[srs5694]

I did not realize that superchargers charge differently based on local electricity rates. I thought that Tesla went to cost per KWH for all chargers to make it more fair.

Tesla has to play by the rules set by each state, and many states forbid anybody but utilities from selling electricity. Tesla (and other EV charge station providers) get around this by charging per-minute rates, often tiered based on the charge rate in kW.

More broadly, ABRP tends to be a bit pessimistic on range, in my experience -- but OTOH, maybe I just drive more efficiently than most people. (I don't speed as much as many do.)

I'd also say that, although ABRP is a useful planning tool to see what's possible, IMHO sticking too closely to a planned route could be a mistake -- or at least, it could create a sub-optimal trip. In my experience with road trips (mostly in ICE vehicles), I may want to stop at a particular time to eat, use the bathroom, etc., and in an EV, I'd rather charge when I do that. If I take scheduled charge stops, then either I'm putting my own biological needs on a schedule dictated by the car's needs, which is entirely backwards; or I'll be doing two types of stops (charging and my own breaks), which will increase drive time. Instead, my strategy on my (so far one and only) Tesla road trip was to use PlugShare and the car's navigation system to identify Superchargers on the route, sometimes planned at the previous stop and sometimes identified in transit, at locations that were good stopping points for my own needs. This worked fine, and in fact I found that I ended up stopping for longer than I needed to for car-charging purposes. I documented my experience here, if you care to check it out.

 

[ewoodrick]

ABRP gave you an option. It probably isn't the only one. Your car will also give you an option.

Going over the Smokies is no big deal. Horrendous numbers going up, but you gain most back on the way down. ABRP should take it into consideration.

Start your trip at 100%.
Don't plan on staying the specific number of minutes. Combine meals and breaks around charging stops. A meal often takes longer than charging.
Feel free to skip chargers along the way, just point the car at the next one to make sure you can do it.
The car will tell you to slow down if it seems you might not make the next stop. But the car is really conservative.
I've been from Atlanta to Dayton OH. Atlanta to Ft Lauderdale. Over the Smokies.

Not a problem. Range anxiety is normal, just takes time to get over it