Ask the EV Experts: Charging Etiquette
05.05.2017 - by Plug In America
Ask the EV Experts: Charging Etiquette

In our latest episode of Ask the EV Experts, we answer a questions from two of our viewers, Joe and Robert. Have a question of your own? Let us know in the comments below, post it on Facebook, Tweet at us, or email us at #AskTheEVExpert

Question 1:

“Does it hurt my car to use only level 2 charging? I’ve heard that it’s a good idea to plug in on a level 1 charger as well. What do you think?”


So the simple answer is yes, plugging in on level 1 instead of level 2 is technically better for overall battery life and health. However, at the end of the day, the car has to be convenient for you. If you need to charge on level 2 to meet your daily needs, then charge on level 2 – and don’t worry about hurting the battery. Charging on level 2 all the time isn’t going to make a significant difference in the lifecycle of your battery.

Question 2:

“When an electric car is parked next to you with its charging door open and there are no available chargers, is that a hint to plug them in when you are done?”


Yes! This is indeed them asking you to plug them in when you’re done. Now this will only work at stations that have free charging, since the charge session at a pay station usually automatically ends when you unplug. However, if you happen to be at a free station, definitely do plug them in – they will appreciate it!

If you have a question that you’d like answered in our next episode, please let us know in the comments below or email us at

16 comments on “Ask the EV Experts: Charging Etiquette”
  1. Howard Johnson says:

    I live in an independent living complex. My garage has no electric outlet except for the garage door opener and I live in San Antonio Tx.. How would I deal with battery recharging for a Tesla X ?

    1. Glennsan says:

      If you can’t get your HOA (?) to install an L2 then the best you could do is use any available public chargers, assuming there are some in your area.

  2. Marc Fontana says:

    Using L2 (208/240v) to charge your EV all the time is fine. Actually, not only is it much faster than charging using 120v, it uses LESS electricity. I measured a 12% difference. So, if you have a choice and want to save energy, use L2 charging, it will cost you less in electricity.

    1. Stanislav Jaracz says:

      During charging, the whole ensemble of electronics is powered. The longer you charge, the more you spend on this “overhead” cost and more wear-N-tear you impose on your vehicle electronics. So, L1 uses more energy and wears down electronics in your vehicle. I think the big difference for battery stability is when charging at L3.

  3. Bill Dale says:

    The better rule is “20/80”, although it is really a matter of the closer you get to 100% or 10%, the more nrgayive the effect it will have on the battery pack life. So if you routinely stayed between 85% and 20%, you would have a longer battery life than if you stayed between 90% and 20%, and even better life than if you stayed between 95% and 20%.

    It is also a matter of how often you find it necessary to charge more than 80%, and 20%.

    If you have a Volt, by fiddling with the settings available using the four small buttons in the middle of the far right section of the dashboard, you will find that Nissan provides one crude setting in which you can select a top charge percentage of 100% or 80%. Ideally, they should have made it selectable by single percentage points, for the following reason:

    Suppose you had a daily commute that could be done with just 83%, but 80% would have taken your charge down too far. That would mean you’d be charging to 100% every night unnecessarily, chipping away at the life span of your battery.

    We should do all we can to make our battery packs last at least another 5 or six years. This is because the battery chemistries keep improving incrementally every year, and in the next few years we are likely to have a radically new and revolutionary chemistry to dramatically increase our range per charge, and other metrics as well such as cost, charge rate, weight, safety (fires, explosions), etc.

    You may have heard of John Goodenough, the British chemist who invented the lithium ion battery in 1984. He is now 94, and running a lab at the University of Texas in Austin; a couple of weeks ago he announced that he had a radically new, solid state (no electrolyte) battery that will provide 3 to 10 times the energy density (the measure of how much range a new EV will have), as, well as bring much less expensive, safer, and non-toxic. All of its key chemical components will be plentiful, making the batteries much easier to make.

    There are other such promising battery candidates, including the “ceramic nanopore” battery being developed at the University of Maryland in Baltimore.

    Batteries with such high energy densities will allow us vehicles with ranges of more than 1000 miles on a single charge..
    wrap your head around that!

    Such a battery chemistry would also allow us to have practical electric powered passenger aircraft.

  4. storm connors says:

    The Volt allows level one or level 2 charging. As far as I have seen, all the public chargers use the J1772 attachment to the vehicle. I don’t know of a “J1771” standard. The only way to get a level 1 charge is to plug the J1772 attachment that came with your Volt into a standard 120v outlet. Have you really looked around your apartment complex to see if there isn’t a 120v receptacle somewhere? Find it and get permission to use it. Maintenance people can be helpful in finding outlets.

  5. Howard Johnson says:

    Jim, I believe that you have a J1772 charger for your Volt……which allows you to use any of the J1772 chargers that are available on the app “Plugshare”…….depending on your location…….
    And yes, it is not good for your battery to be exhausted for a long period of time…See Alan’s comment above……

  6. Yesac says:

    What is Level 2 exactly?

    1. BAJohnson says:

      220v (up to) 40amp charging via a J1772 plug. Much faster than using 120v 15amps. Much slower than using 440VDC fast charging via the Chademo port.

    2. Howard Johnson says:

      240 volts…… In comparison, level 1 is like your home wall receptacles that are 120 volts……
      You simply get a faster charge @ level 2…….

  7. Ben Schmid says:

    What work is being done on making it possible to use the energy in an electric car battery in a household when the power goes out? Critical loads may need to be powered, eg medical devices, sump pumps, furnaces, etc.

    1. Cary Budach says:

      If you need to power critical loads with your electric vehicle..> Try this: You should have a 12v battery onboard. It’ powers the radio, blower motor, wipers, dash lights, head and tail lights, interior light, etc. Somewhere there also exists a dc/dc converter… that takes your drive battery and recharges the 12v battery. (Only when the vehicle is ‘on’ and ready to drive). Go to harbor Freight, get a cheap 2000 watt inverter, and clip it to the 12v battery. The drive battery will power this unit for many days. Easy and always ready.. Just don’t drain yourself dry… Keep an eye to have enough juice to get to the nearest recharge station.

      1. Marc Fontana says:

        I have had bad experiences with “cheap” (ie modified sine) inverters causing damage to some appliances. Some loads don’t care, but to be on the safe side, i would stick with “Pure Sine” inverters if you don’t want to damage any sensitive electronics.

  8. Alan Soule says:

    While charging with Level 1 may be theoretically better for your battery than charging with Level 2 and better than fast charging, my experience is that the Level of charging has not noticeably degraded my battery. What does noticeably degrade my battery is charging to more than 90% state of charge or running the battery down to less than 10% state of charge. I have a Roadster and a Model S. Before I learned the 10-90 rule I would charge the Roadster to 100% most of the time and the battery range decreased significantly. I learned the 10-90 rule before I got my Model S and have 85 K miles on it with no decrease in the battery range. I have fast charged dozens of times. I attribute this to never having charged the car above 90% nor discharged it below 10%.

  9. Jim Aydelott says:

    We drive a 2014 Volt and recently moved into apartments. For two years we lived in a house where we plugged in every night and seldom bought gas. The apartments do not have any place to allow plugging in the Volt so we have an empty battery most of the time except when we can find a charger (level one) and that is seldom.. Will it damage the battery at all to be empty as described above? We wish Chevrolet would put a level two charging ability into the Volt, the adapters do not allow anything but J1771s

    1. Michael Murphy says:

      Jim: your battery is not actually empty. Your 2014 Volt will discharge to about 22% SOC-RAW when it is at 0% SOC-USABLE, and is at about 88% SOC-R when at 100% SOC-U. It will not damage your battery to be at that level for a long time. BTW, your car has level 2 capability: that is governed by the supply equipment. Your plug is J1772. there is no such thing as J1771.

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