Charging Habits

[sleepies]

After reading many columns and threads, I’m still a bit confused on the best way to charge my Model Y.

My daily commute to work is 2 miles each way. I currently rent a room in a townhome with no home charging but my workplace provides free charging. Every Friday after work, I drive 130 miles back home where I do have a home charger installed in the garage of my primary residence. Then on Monday or Tuesday morning (depends on when I flex - 9/80 schedule), I drive 130 miles back to work and charge at work to 90%. Then rinse and repeat.

(1) Should I charge each weekday to 90% at work and then stop to free up a spot for another car to charge.
(2) Keep it plugged in all day until I’m off (this will make me hog a spot and prevent others from charging).
(3) Charge when I get back to work from the weekend to 90% then don’t charge the rest of the week until Friday before I head home for the weekend?
(4) Or any other recommendations?

Sorry, I have a headache myself just thinking about all these possibilities.

 

[jcanoe]

(1) Yes
(2) No
(3a) Charge to 90% when you get back to work after the weekend. (3b) you don't have to charge every day but you may want to if you use Sentry mode.
(4) Extra Strength Tylenol

 

[DonaldBecker]

It doesn't matter that much.
Keeping the state of charge between 50-80% is very slightly better than 30-90%.
I suggest charging to 80-90% at the beginning of the week, and only topping up if you drop below 50%. Then charge to 90% just before the trip home.

It is better to charge to 95% or 100% indicated than drop below 20%.

 

[silverstoned83]

If you want to make to most out of the free charging at work, I suggest charging to 100% on Friday, while ensuring that you leave work shortly after it finishes. When you get home, only give it enough charge to get back to work on Monday, which may be nothing at all depending on how efficient your driving habits are. When you get back to work, your SoC should be low, 10-20%.
At this point, I suggest maintaining a charge between 50-70%, especially since it’s such a short trip. If you’re not using sentry mode, you could probably get away with charging to 70% on Monday and not have to worry about topping up until Friday.
This approach will certainly have an impact on your electric bill.

 

[frankvb]

How about biking or walking to work

 

[Big Earl]

Charging every day seems silly when you’re only consuming <10 miles of rated range. It’s also inconvenient to move the car every day after less than 30 minutes on the charger, which segues into scenario two, which is very poor charging etiquette.

Scenario three will lower your average state of charge for the week. I personally like to keep the car more than half full in the event I need to drive a long distance unexpectedly.

My recommendation is to charge at work twice per week. Once before your trip and once on your first day back. That has you using the communal chargers only twice per week, vacating the charging station at lunch and keeping your average range up in case of an unexpected travel event. If you end up consuming more range than expected due to extensive preheating or additional weekday driving, add a third charging session to your work routine.

 

[TexasNancy]

I'm sorry to say I misunderstood Elon Musk when he said don't let the battery get below 20% and don't charge it above 80%, except for long road trips. I charge my Model Y up to 80% and plug it in to charge when it's at about 40%. Evidently, I'm supposed to plug it in "when not in use", which seems a bit ridiculous to plug, unplug, plug, unplug four or five times a day. My new charging routine will be to plug it in every evening and charge up to 80%. Only once have I let the car get down to 10% due to an unexpected side trip.

 

[Big Earl]

I'm sorry to say I misunderstood Elon Musk when he said don't let the battery get below 20% and don't charge it above 80%, except for long road trips. I charge my Model Y up to 80% and plug it in to charge when it's at about 40%. Evidently, I'm supposed to plug it in "when not in use", which seems a bit ridiculous to plug, unplug, plug, unplug four or five times a day. My new charging routine will be to plug it in every evening and charge up to 80%. Only once have I let the car get down to 10% due to an unexpected side trip.

You don't need to plug it in constantly. It's fine to continue doing what you were doing before - charge to 80% and recharge when you get to 40%. "A happy Tesla is a plugged in Tesla" is an oversimplification.

 

[TexasNancy]

You don't need to plug it in constantly. It's fine to continue doing what you were doing before - charge to 80% and recharge when you get to 40%. "A happy Tesla is a plugged in Tesla" is an oversimplification.

I'm glad to hear that. I was just following Elon's advice (on Twitter). My car's battery seems to be fine and I've had it a year and a half. Thanks for your input! Greatly appreciated!

 

[jcanoe]

I'm sorry to say I misunderstood Elon Musk when he said don't let the battery get below 20% and don't charge it above 80%, except for long road trips. I charge my Model Y up to 80% and plug it in to charge when it's at about 40%. Evidently, I'm supposed to plug it in "when not in use", which seems a bit ridiculous to plug, unplug, plug, unplug four or five times a day. My new charging routine will be to plug it in every evening and charge up to 80%. Only once have I let the car get down to 10% due to an unexpected side trip.

If would be rare to have to plug in to charge more than once a day. Constant plugging and unplugging just adds wear and tear. If you want to be grid friendly, setup Scheduled Departure so that your Tesla Model Y completes charging by 0600 or whatever time you choose. In general the period between 9PM and 6AM is when the grid is least heavily loaded. Off-peak kWh rates may be available from your local utility if you sign up for one of the time of use (TOU) rate plans. (You may be able to shave a few cents per kWh off of the current $0.115 rate.)

 

[TexasNancy]

If would be rare to have to plug in to charge more than once a day. Constant plugging and unplugging just adds wear and tear. If you want to be grid friendly, setup Scheduled Departure so that your Tesla Model Y completes charging by 0600 or whatever time you choose. In general the period between 9PM and 6AM is when the grid is least heavily loaded. Off-peak kWh rates may be available from your local utility if you sign up for one of the time of use (TOU) rate plans.

I currently charge once a week when the battery is at 40% and I do so at night. I'm not concerned about what time to charge or the cost. I'm concerned about the battery life. If charging daily is better than charging weekly, then I will change my charge routine, but Big Earl told me what I was doing was just fine. So...I will continue with my old charging routine. Thanks for the advice!

 

[jcanoe]

I currently charge once a week when the battery is at 40% and I do so at night. I'm not concerned about what time to charge or the cost. I'm concerned about the battery life. If charging daily is better than charging weekly, then I will change my charge routine, but Big Earl told me what I was doing was just fine. So...I will continue with my old charging routine. Thanks for the advice!

There is some lithium battery charging test data that shows that charging up to 60% or 70% would be a bit better than charging up to 80% (but leave you without as much range if you suddenly decide to take a trip.) Charging daily, keeping the battery within 10% of one of those values would be even better but not provide much usable range.

I drive very little, end up charging about every other day and on weekends for 90 minute charging sessions (free 2 hour parking, with free 6kW charging.) In general this enables me to maintain the battery between 55% and 85%. I believe that my 2020 Tesla Model Y will be functionally, technologically obsolete within 5 years, long before the battery has significant degradation. Either that or an encounter with deer or a collision with another vehicle will take out my Model Y.

 

[TexasNancy]

There is some lithium battery charging test data that shows that charging up to 60% or 70% would be a bit better than charging up to 80% (but leave you without as much range if you suddenly decide to take a trip.)

Yeah, I've read that too and you're right, not much range. I can drive from Irving to north of Decatur and back on 80%. Thanks!