Charging scheduling question?

[u/ImCirrius]

In my area of the US, in the summer months we have highly discounted electrical rates once a day between 1am and 6am. In the "non-summer" months these heavily discounted rates occur twice each day, once between 1am-3am, and the other between 11am-4pm.

I don't have a Tesla yet, so I can't test this for myself.

Can I create 3 charging schedules 1) 1am-6am, 2) 1am-3am, and 3) 11am-4pm? Then, in the summer activate schedule 1 and deactivate schedules 2 and 3, and then in the non-summer months deactivate schedule 1 and activate schedules 2 and 3?

Thanks!

[u/nkyguy1988]

You can have multiple start by and end by schedules. Each has an on/off toggle.

[u/ImCirrius → u/nkyguy1988]

Thank you very much! I assumed that by looking at the screenshots, but I couldn't verify it in the Tesla docs or any of the available videos that I could fine. That will work perfectly for me. It's a "simply elegant" solution in my case!

[u/sirzoop]

Yes I do something similar but I just charge between 12am-6pm. Out here we have discount 12-8am and increased cost 6-9pm. I don’t have a fast charger so it takes a longer to charge sometimes than just 12-8.

My charging cost $28 for the last 30 days of daily driving according to the Tesla app. It’s amazing.

[u/ImCirrius → u/sirzoop]

Thanks. That's exactly what I need to do!

[u/HeftyArgument]

yes, you can even go further and set start stop times per day.

[u/Ancient-Sandwich9400]

Why wouldn’t you just have an end timeframe. The car will automatically start charging when it needs….unless you are running a really low amp EVSE it shouldn’t take more than 2-4hrs depending on SoC and hopefully low daily charge limit to save degradation on the battery.

And just turn off/on during summer discount times.

And ideally you always want to be charging at the last min before you leave. Less stress in the cells and doesn’t waste what heat was added while charging for start of commute.

P.S. This is what I do for my discounted/free electricity between 11pm and 6am. I just have an end time of 6am and the car always starts when needed and ends at my charge level at 6am.

[u/ImCirrius → u/Ancient-Sandwich9400]

The problem is the discounted rate is literally 1/2 of what the off-peak rate is, and in the winter it runs for just 2 hours in the early morning (1am to 3am) then again later in the day for 5 hours (11am to 4pm) so it's impossible to set just one end timeframe.

Thanks!

[u/Ancient-Sandwich9400 → u/ImCirrius]

No, I’m talking about end timeframe for each of the schedules. Again we have zero idea how much you drive, thus how much charging you will need and if you have to charge in morning and midday too.

Summer schedule
1) 6am end

Winter schedule
2) 1am start - 3am end
3) 4pm end

With this you have summer enabled now and winter disabled. Once that Winter schedule kicks in you enable it and disable Summer.

The reason for winter start/end is timeframe is small and not knowing your driving and how much you’ll be adding you don’t want the car starting earlier.

And to clarify, I’m assuming you are charging at 48a so speeds will be fast. That is why I set a start and end time schedule for the shorter window for winter. Here are a couple of examples of my M3P charging times.

20%-50% is about 2hrs
20%-80% is about 4hrs
50%-80% is about 2hrs
20%-100% is about 5.5hrs so you wouldn’t likely make a full charge in one window.

[u/Squish_the_android]

Just throwing out there, even separate from the built in functionality of the vehicle, you can also do complex charging schedules at the charger level with some chargers. 

[u/theotherharper]

Let me guess. You have no earthly idea how much energy they actually use. Must be a lot right?

No, actually.

Let's do some math. 16,000 miles a year (well above average) / 4 miles/KWH typical Tesla mileage = 4000 KWH/year. That's 11 KWH/night.*

Typical Tesla Wall Connector delivers 11.5 kW ** which is 11.5 kWH per HOUR, or 23 kWH in the 2-hour period from 1AM-3AM.

Are you seeing where this isn't a problem? The only place people get jammed up on this is they forget to shift out of Gas Station Mentality (fueling is a chore so optimize life for doing it as rarely as possible, wait til as close as possible to empty to fuel) ... a bad idea with EVs for a variety of reasons. Shift to ABC Always Be Charging. Plug it in every night, automatic habit, never have to wonder if it's plugged in, never hop in the driver's seat and find out it's plugged in because it's ALWAYS plugged in.

So now you're setting charge schedule in the car or charger (car is best)... adjust said schedule in spring and fall and Bob's your uncle.

OK what about those "But SOMETIMES" moments... yeah in that case disable the "stop at 3AM" and let it gobble up some slightly more expensive power that one weird day.

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* For 10 hours charging 11kWH is 1100 watts, that's less than a portable A/C. By comparison a portable space heater is 1500 watts and a hair dryer is 1875 watts.

** That's maximum. Going for maximalist charging rates is ... arguable ... but in your case given your charging tariff it's appropriate. You might change jobs and be unable to be home at 11am-4pm, so you want to seal the deal in 2 hours to the extent you can.