Charging a Tesla is all about keeping within limits for battery longevity. What if you need to go on a trip within the maximum range? But your Tesla won’t charge to 100%. Read on to find the solution.
Tesla won’t charge to 100 because a charge limit is set, the onboard computers protect the battery, or a Battery Management System calibration is required.
In this article, we’ll look at why your Tesla won’t charge to 100 and tips to get the battery back charging to its highest capacity.
Tesla Charge Limit Set
The most common reason for your Tesla not charging all the way to 100% is that the charge limit is set below 100. This makes sense.
Tesla recommends that we charge a Tesla daily at home and keep the range between 20% and 80%. This prolongs the life of the battery. The more you charge above that upper level, the hotter your battery will get leading to long-term degradation. The charging limit can be checked and altered through the Tesla App and the car’s touchscreen.
You can move the slider to 100%, but this is advised only if absolutely required. Why would you need to charge 100%? The obvious reason is that – you need the extra range for a trip. And even at that, the SuperCharger network nationally is enormous and has plenty of opportunities to charge.
For day-to-day charging and commuting, having your battery capacity at 100% daily is unnecessary. If your commute is a round trip of 200-300 miles per day, then your battery range needs to be high, but the reality is that most people travel 50-60 miles per day, and a charge of 50% is more than adequate.
Tesla recommends charging your car daily, using a Tesla Wall Connector, to a maximum of 80%.
In fact, when Elon was asked if a Tesla should be charged 100%? His answer was No; it should only be charged to 80-85%. If your car is charged to 100%, then the regenerative braking system can’t function properly.
The regenerative brakes generate energy for the high-voltage battery every time they are used. As the battery is already charged to 100%, this wastes the additional energy, making your Tesla inefficient with energy use.
As I said, your high-voltage Tesla battery is the most crucial element of your car. Without it, you’re not going anywhere. But along with your high voltage battery is the high-tech onboard computer. The brain of your car.
The computer is constantly monitoring your activity. The way you’re driving. How you’re charging and how often you’re charging.
The reason behind all this analysis is to protect the life of your Li-Ion battery. The more often your Tesla is charged to 100%, the higher the risk of cell damage.
Over time, this leads to individual cells (of which there are just under 7000) dying. This, in turn, leads to your Tesla no longer being able to accept a full 100% charge.
The onboard computers (and Tesla) want your battery to last for years, and to make this a reality, the computer can actually limit the amount of charge going to your battery.
It’s basically assessing the situation and taking over the decision-making. This is especially the case if you use a Supercharger regularly. I wrote a post that covers why that is in more detail – Supercharging payment failed.
Superchargers use DC charging and a higher temperature. Your Li-Ion is being exposed to a higher temperature more often, and overall longevity will decrease.
It’s Tesla’s way of saving your battery. If you have your limit set to 100%, but you can only achieve 85-90%, this is likely the reason behind it. Tesla can switch out dead cells but be aware that they also know through your computer the complete breakdown of your charging history and setup.
If you have been abusing (letting your battery range deplete regularly) your car, they may decide to charge for the cell refit, even though the car may still be within warranty.
BMS (Brake Management System) Calibration Required
The onboard computers base your charging limits on your average charging ways or routine. If you constantly charge from 50-80%, the computer can become out of sync. It loses the ability to know the limits of charge available.
This is why it’s a good idea every month (or two) to get in the habit of recalibrating your battery.
It has been known to increase battery range by up to an additional 5%.
You need to plan when you will carry out the procedure, as although your Tesla is still in use, you need access to a charger.
Why is this? Well, to recalibrate, it is necessary to deplete the battery to as low as you can without becoming stranded. This might mean no charging for a few days or not leaving your home.
You also need to deactivate Sentry Mode and also deactivate any third-party apps you have installed. This is so the battery can learn precisely the limits from bottom to top.
When your battery is as low as you can, you need to charge it (preferably with a TWC) to 100%. When it reaches 100%, don’t disconnect it immediately. If it says that it is still drawing power, leave it until it is finished.
I know what you’re thinking! I’ve just told you not to charge to 100% to protect your battery, and now I’m telling you to charge to 100%.
For one, this is a very occasional operation. The thinking behind this is that for your battery to have its full potential, it has to learn the upper and lower limits. It allows all cells (or as many as possible) to reach full capacity.
Your future charging then occurs at a more proportional rate. All cells increase or decrease together, leaving less of a strain on your battery over time.
In the grand scheme of things, your battery not achieving 100% is not unusual and not something you should be aiming for each charge. If your limit is set to 80-85%, you’ll get more efficiency from your Tesla long into the future.
If, on the other hand, you feel that your range is rapidly depleting or you’re not achieving the range you should be, it’s always worth talking with a Tesla Service Center so they can do a health check.
I’ve written a ton on common Tesla issues, which hopefully you won’t ever experience, but if you do, we have you covered with these posts:
Check out the Tesla troubleshooting page for problem Teslas.
Check out the Tesla charging page for common Tesla charging problems.
Check out the Tesla category page for a list of popular Tesla posts.
If you are curious about other EV models, check out the EV FAQ category.
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