Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Always Be Connected?

This site may earn commission on affiliate links.
Hi,

I remember reading about Always Being Connected/Charging (ABC).

What benefit does this have?


I have left my car plugged in using a 32amp commando and the UMC, stopped it from charging to see what would happen.
I was hoping that the car would be powered from this instead of using the batteries but I could see battery level going down still during the day.

I also tried setting it up for charge but leaving the charge level below what it currently was set to, just incase this was the issue.



What I ideally want is to power the car from the wall instead of adding additional charge cycles to the car that can be avoided.
If what I done above is correct, then why was my charge level still going down?
 
Understanding how your car gets power should help...

When you have your car plugged in to an AC power source (like the setup you mentioned using your UMC) there is an important distinction to be made: The UMC IS NOT THE BATTERY CHARGER. All the UMC does is provide a source of power to the car's built in battery charger. This unit is located on the car itself. The onboard battery charger takes AC power, converts it to DC, and charges the car's main battery.

Whenever you have your car connected to AC power, the car's built in battery charger is what charges the battery.

Another important distinction to be made: your car is always powered by the battery. If you happen to be able to supply the car with more power than what the car is actually using at the moment, you might also be charging the battery at the same time, but at no point in time does the UMC itself actually power the car; the battery always does that. (Edit: OK, that's not exactly what happens, but from an owner's standpoint, it's easiest to think of it in those terms.) The only thing the UMC does is provide power to the car's onboard battery charger. So if you have the UMC plugged in, but have disabled charging, it can't do a thing to "power your car."

Simply plugging in the UMC does nothing if you have stopped the charging process; you might as well unplug it at that point. The ONLY thing the UMC does is provide the onboard battery charger with a source of power.

Also, keeping the car plugged in to keep the battery topped up to whatever charge level you have set doesn't add additional charge cycles to the battery. There is far less wear and tear on a battery that is only being charged up a small amount daily (to say, offset phantom drain) than a battery that just went from 100% full to 5% full and then was SuperCharged back up to full charge again. Trickle charging your car at home with a UMC to keep it topped up (assuming you're not keeping the pack at 100% charge level) is not harmful to the battery pack at all.

To those that have a bit of a pedantic twist to them: Yes, I know. But let's leave it at this, as it's close enough. No need to get into the weeds, as it's pretty clear that the OP just needs a bit of understanding to help them out.
 
Last edited:
One thing is that every time you open the app it wakes up the car, starting a number of systems and increasing drain. Like waking your laptop from sleep.

Beyond that, I wouldn't overthink it. Tesla recommends to just leave it plugged into a power source. That's basically what everyone does and there are no significant issues from that that I've heard of.
 
I understand what you mean about the UMC not being an actual charger and the difference between AC and DC.

I would have been nice if it was possible for the charger to act as an inverter to power the car while connected instead of using the onboard batteries, this is what I though happened which is why I was questioning it.

In regards to the additional charge cycles, eventually after using battery power and then recharging, it will count as a full charge cycle?

What is the actual benefit of Always Being Connected/Charging? Vs me just topping up to the 80-90% each day?
 
What is the actual benefit of Always Being Connected/Charging? Vs me just topping up to the 80-90% each day?
The most important way to preserve the Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it. This is particularly important if you are not planning to drive Model 3 for several weeks. When plugged in, Model 3 wakes up when needed to automatically maintain a charge level that maximizes the lifetime of the Battery. NOTE: When left idle and unplugged, your vehicle periodically uses energy from the Battery for system tests and recharging the 12V battery when necessary. There is no advantage to waiting until the Battery’s level is low before charging. In fact, the Battery performs best when charged regularly.

NOTE: If you allow the Battery to discharge to 0%, other components may become damaged or require replacement (for example, the 12V battery). In these cases, you are responsible for repair and/or transporting expenses. Discharge-related expenses are not covered by the warranty or under the Roadside Assistance policy. The peak charging rate of the Battery may decrease slightly after a large number of DC Fast Charging sessions, such as those at Superchargers. To ensure maximum driving range and Battery safety, the Battery charge rate is decreased when the Battery is too cold, when the Battery’s charge is nearly full, and when the Battery conditions change with usage and age. These changes in the condition of the Battery are driven by battery physics and may increase the total Supercharging duration by a few minutes over time.
 
  • Like
  • Informative
Reactions: hcdavis3 and Fizzyo
I understand what you mean about the UMC not being an actual charger and the difference between AC and DC.

I would have been nice if it was possible for the charger to act as an inverter to power the car while connected instead of using the onboard batteries, this is what I though happened which is why I was questioning it.

In regards to the additional charge cycles, eventually after using battery power and then recharging, it will count as a full charge cycle?

What is the actual benefit of Always Being Connected/Charging? Vs me just topping up to the 80-90% each day?

Its not much different, other than the car being able to automatically top the battery back up, and have the car have the amount of battery charge you expect when you go to drive it.

Tesla advises that because its "easier" for owners to remember to plug in every day, rather than possibly forget one day and not have enough charge.

Also, there is no harm in charging the battery daily, or even more than daily (every time it is in a place to charge). Charging cycles are an entire cycle from 0-100% so when you read "the battery has XXXX cycles capacity on average", thats cycles from 0-100, so if you drive 100-0 every day, thats 15 hundred charges. If you drove 100-50% every day, thats 3000 cycles.

If you drove 90-80% every day, thats basically 15,000 cycles.

Its "easiest" to plug it in every day, but its not necessary. Just dont charge over 90 ish percent unless you need to, and dont run it down to 10% unless you need to.
 
The most important way to preserve the Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it. This is particularly important if you are not planning to drive Model 3 for several weeks. When plugged in, Model 3 wakes up when needed to automatically maintain a charge level that maximizes the lifetime of the Battery. NOTE: When left idle and unplugged, your vehicle periodically uses energy from the Battery for system tests and recharging the 12V battery when necessary. There is no advantage to waiting until the Battery’s level is low before charging. In fact, the Battery performs best when charged regularly.

NOTE: If you allow the Battery to discharge to 0%, other components may become damaged or require replacement (for example, the 12V battery). In these cases, you are responsible for repair and/or transporting expenses. Discharge-related expenses are not covered by the warranty or under the Roadside Assistance policy. The peak charging rate of the Battery may decrease slightly after a large number of DC Fast Charging sessions, such as those at Superchargers. To ensure maximum driving range and Battery safety, the Battery charge rate is decreased when the Battery is too cold, when the Battery’s charge is nearly full, and when the Battery conditions change with usage and age. These changes in the condition of the Battery are driven by battery physics and may increase the total Supercharging duration by a few minutes over time.


Note, OP, this quote is the exact quote from tesla in the manual (I have copy / pasted it enough over time to recognize it as the exact quotations from tesla in the manual on this topic).
 
any words on durability of charge port and charge port door opening/ close mechanism ? if you plug / unplug every day you are going thru 2x cycles / day ... 730 / year ... 3,650 / after 5 years .... not sure if that door mechanism which is powered by a little motor is rated for much more than that..
 
  • Funny
Reactions: Gasaraki
Hi,

I remember reading about Always Being Connected/Charging (ABC).

What benefit does this have?


I have left my car plugged in using a 32amp commando and the UMC, stopped it from charging to see what would happen.
I was hoping that the car would be powered from this instead of using the batteries but I could see battery level going down still during the day.

I also tried setting it up for charge but leaving the charge level below what it currently was set to, just incase this was the issue.



What I ideally want is to power the car from the wall instead of adding additional charge cycles to the car that can be avoided.
If what I done above is correct, then why was my charge level still going down?

To add to other people's comments, leaving it plugged in DOES NOT INCREASE YOUR CHARGE CYCLES.

Define: Charge cycle - One charge cycle is 100% to 0% then back to 100%.

Scenario 1 - I don't leave it plugged in. Lets say the car naturally drains 1% per day. The car is set to 50% charge level and I unplug and let it sit for 5 days. On day 5, I'm at 45% charge. If I then realize that I need to go somewhere and I charge it back up to 50%, then head out.

Scenario 2 - I leave the car plugged in. The car is kept at 50%. Lets say that the car "charges" whenever it drop one percent. So over the 5 days it would "charge" 5 times for 1% each.

You are assuming that a "charge cycle" is every time the car charges the battery, so in scenario 1 it would be one cycle because it only charged once and in scenario 2 it with be 5 cycles because 5 times. THIS IS NOT TRUE

They both charged 5 percent so it put the same amount of "cycles" in to the car, which is .05 of one cycle.
 
  • Like
Reactions: Phlier and Skione65
I just have the cable connected, set to charging all the time. I think there is some way to configure it so it allows it to drain for a bit, then recharges once a day. Maybe using scheduled departure?
Ours is plugged in all the time it's garaged, but only scheduled to charge to 60% at 10pm nightly. Aside from the scheduled charge anytime we open the car during the day and the HVAC kicks in it does start drawing AC too, presumably to offset that usage.
 
Leaving it plugged in benefits:

- Makes sure your battery stays at 50% or greater in case life happens and you end up not driving for a week or more
- Allows you to pre-condition battery and cabin without using as much battery power (assuming you're on L2)
- Allows you to set it to 90-100% while laying in bed and you suddenly decide to drive to Vegas in the morning
- Helps promote shallower discharges of the battery, which is gentler than deeper discharges
- Gives you "set and and forget it" peace of mind. The car will do the rest.
- and I'm sure more that others' will think of.

Not leaving it plugged in benefits:

- No risk of strangers tripping over the cord.

I don't think anyone is suggesting plugging it in repeatedly as you go about your normal day and run little errands. Just plug it in when you expect you're done with your car each day. Or if you're on a long road trip, then the mantra of "Always be charging" is beneficial because you might as well be topping up whenever you can to avoid wasting time. Eating lunch, using restroom, roadside attraction.... if there's a charger... plug in. That way your time spent waiting for a charge is reduced.

In the same way my mother used to make me finish my dinner "because there are starving kids in Africa..." I choose to plug in my car whenever its at home for all the apartment dwellers who wish they could do the same...
 
  • Helpful
Reactions: Acps110
I lived in an apartment where I could not install a charger for over 1 year and my only charging options were public charging. So my car remained unplugged most of the time. Tesla's recommendation to keep it plugged in are very general in nature so people don't end up with a very low state of charge and then go on vacation and leave the car that way for extended periods. If you know how to manage the situation and keep your SoC above 50% (mine was always relaxing at 80-90%) you won't have any issues. I've been using TeslaFi and Teslamate since day 1 and also don't have any abnormal degradation. I'm now finally in a new townhome and have a charger at home and do keep it plugged in, but it's not something that will hurt you if you don't follow this practice AS LONG AS you do not let the car sit at a low SoC for extended periods. My solution was to use the public charger 2 miles away when needed which was typically only once a week during that period.
 
  • Like
Reactions: Zoomit