Is it Better to Charge a Tesla Slowly? I would!


Owning a Tesla is fantastic, but it comes with specific questions about EVs. Charging is the most pressing issue, and the question is whether you should charge your Tesla slowly. I’m a mechanic and will give you the information you need to charge in the best way possible.

Charging your Tesla slowly will be better for your battery life; Tesla recommends you charge your car daily at home and only Supercharge when necessary.

In this article, we’ll look at the benefits of charging slowly and some negatives involved.

Row-of-Tesla-cars-on-charge-at-Superchargers
Infographic - Is it better to charge a Tesla slowly?

Charging Your Tesla Slowly

Tesla recommends that your car is charged daily at home. They also suggest that you keep the range between 20 – 80%. But does charging your Tesla slowly actually benefit your car, or does it even matter?

Your Tesla is powered by Lithium-Ion batteries. They perform better if they are charged at a constant temperature. The slower the charge, the lower the temperature.

However, slower charging takes longer, so the battery works harder for the same amount of charge. This is especially true if you are using a 120V Level 1 charger. Although the batteries are not getting hot, they are heating to a specific temperature over a much more extended period, and so battery degradation is occurring.

SlowMediumFast (Supercharge)
120V240VDC Charge
3-4 Days6 – 25 hours30 minutes
1-2 miles / hour50+ miles / hour170 miles in 30 mins

For many owners, the 120V is insufficient to charge your car for daily driving. If you are doing a commute of 60-80 miles per day, then Level 1 is not going to give you enough charge overnight.

The better option is the 240V Level 2. This is a better choice for slower charging without generating the heat that a Supercharger creates.

The older your Tesla, the less efficient the battery becomes. This is a pretty standard phenomenon for Li-Ion batteries. (Smartphones work on the same basis).

Over time some of the cells die off. The warranty on your Tesla battery is different for each model.

Model 3Model XModel YModel S
8 Yrs / 120,000 miles8 Yrs / 150,000 miles8 Yrs / 120,000 miles8 Yrs / 150,000 miles

However, you might run into battery problems before then because of the way you are charging. If your battery is still under warranty and no longer charging to the correct capacity, I would advise making an appointment with Tesla Service Center.

They won’t replace the complete battery, but they will switch out any dead cells. But they also can check if you have been neglecting your charging process.

How Often Do You Use Your Tesla?

Most drivers use their Tesla every day, and the length of their commute will determine the charging schedule.

If you only occasionally use your Tesla, you must keep a regular charge in your battery. Overheating of the battery is damaging but equally damaging, allowing the charge to go below 20%. Even though you’re not using your Tesla, it still needs the power to check the system’s health.

Your Tesla could require 1% per day of battery use depending on climate (very hot or very cold could use more). The most common reason for your Tesla to reach 0% is lack of use because it’s a secondary car or on a prolonged vacation.

If your Tesla use is sporadic, you should have it plugged in permanently with at least a 120V charger. This will preserve the life of your battery.

If you are regularly allowing the battery to discharge completely and run into problems with your Tesla, that Tesla can easily do a check on your onboard computer. It is, after all, a large computer with wheels, and you will be charged accordingly for the cell damage.

Alternative Charging

As discussed, the recommended charging schedule from Tesla is to keep your battery level between 20 and 80% and to charge daily from home.

But I know what you’re asking… I have a Tesla with Free Supercharging, so why would I not avail of this? And you’re right to ask because Free Supercharging is not something that is offered widely anymore.

Free Supercharging is not transferable from pre-2017 cars, and even the original Model S40 didn’t offer it as standard.

But there are still plenty of Teslas out there with the original owner that can avail of the free Supercharge.

Free is free, right? well, yes, but you must consider what effect this has on your battery. When Tesla launched in 2012, it also launched the Supercharge Network. Musk didn’t want Tesla owners to be confined to one area. The Supercharge Network spans the length and breadth of the States.

But the truth is that Supercharging your Tesla regularly is not good for your battery life. Home charging uses AC power, but Superchargers use DC power. This is why in fairness, we can reach 170 miles in 30 minutes of charging.

But charging using DC produces a lot of heat. And Supercharging regularly, over time, degrades your battery. Your onboard computers have a battery-saving component that will only charge to 90% if conditions are not acceptable.

The less you Supercharge, the longer your battery will retain its ability to hold a full charge. There are only so many charging cycles available in your Tesla life, and it doesn’t matter if this is achieved through Level 1 or SUpercharge.

On the upside, Tesla is constantly upgrading their systems, and the battery that is in a 2012 S is nowhere near as good as a 2022 model.

Overall, charging your Tesla slowly is better for your battery life, but Supercharging is sometimes necessary if you’re on a trip.

The occasional Supercharge is not going to cause too much damage.

Other posts you might find useful:

Tesla won’t charge in the cold

Tesla Model 3 won’t charge

Can you charge a Tesla with Jumper Cables?

Tesla Supercharger Won’t Start

E John Cunningham

Hey, I’m John and I'm a technical writer here at EVjuicedup.com. I’m a Red Seal qualified Auto Service Technician with over twenty-five years experience working on Classic and Modern Cars. I've worked for GM, Jaguar, Land Rover, Volvo, Audi, and VW main dealers. Yep, I’ve skint my knuckles on them all!

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