Tesla can use the motor to warm the battery itself. In this case, about 4% of the battery was used just to raise battery temperature. Tesla does this to protect the battery. So if you ever notice a small battery drop without driving, it’s not a problem. It’s simply the car taking care of its battery.

When comparing Tesla charging data, an interesting pattern appears. Under similar charging currents, NCM batteries heat up more, while LFP batteries stay noticeably cooler. At first glance, this looks counter-intuitive. LFP chemistry is well known for being more thermally robust.

This charging session is not Supercharging. As battery level approaches ~80%, the current starts to decrease, so charging speed goes down. Even so, the battery module temperature keeps rising continuously and exceeds 50 °C over about 10 minutes. In other words, temperature increases despite lower charging power, mainly at high battery level. This is one practical reason Tesla recommends daily charging up to around 80%. It’s not only about fast charging, but about reducing tim

This experiment is based on a user scenario involving a vehicle that is already out of warranty and has shown signs of the BMS a079 symptom. The approach focuses on keeping the vehicle operating as stably as possible for as long as possible, while accepting a certain level of inconvenience. It has now been eight weeks since the BMS a079 symptom was first detected. So far, the BMS a079 error code has not occurred even once. Around the third week, the battery condition showed s

This experiment is based on a user scenario in which a vehicle that is already out of warranty shows BMS a079 symptoms, and the owner tries to continue using the car as stably as possible while accepting a certain level of inconvenience. It has now been five weeks since the BMS a079 phenomenon was first detected. So far, the BMS a079 error code has still never appeared. At around week 3, the battery condition worsened slightly. So, we limited the charging level to 60% and cap

This experiment is based on a user scenario in which a vehicle that is already out of warranty shows BMS a079 symptoms, and the owner tries to keep using the vehicle as stably as possible while accepting a certain level of inconvenience. This is the third-week result since the first detection of the BMS a079 phenomenon. So far, the BMS a079 error code has not actually occurred. In last week’s middle graph, the cell voltage deviation widened up to 0.09 V. Starting this week, h

These days, because of recent Tesla issues, many people say things like “using cylindrical cells was a mistake” or “Tesla had no choice but to use them.” That might have been true long ago when prismatic and pouch cells were not widely available. But even today, choosing a cell type is far from a simple decision. In battery pack design, there is always a trade-off. Safety, energy density, manufacturing complexity, and cost are all interconnected, and the outcome depends on wh

This is the second week’s result since the first detection of the BMS a079 phenomenon last week. So far, the BMS a079 error code has not yet appeared. As shown in the left graph, even under the same charging conditions, the maximum cell deviation remains around 0.05 V, similar to last week. However, in the right graph, the maximum deviation has increased significantly to about 0.08 V. This difference is also clearly visible in the statistical data. While it’s possible to redu

I recently came across a post on Reddit’s DrEVdev where someone cited an article claiming that Tesla Supercharging is not related to battery degradation. I will not specify the original source here. Collecting and analyzing such data is not an easy task, and I have no intention of criticizing the author. However, since the article has been widely referenced in blogs and YouTube videos, leading some people to believe that fast charging has no relation to battery degradation, I

Although we have analyzed numerous user datasets and real-world cases, this is the first time we have personally observed the same issue on our own vehicle. This gives us a valuable opportunity to study the problem not only from the developer’s perspective but also as an actual owner experiencing it firsthand. To share some background: the vehicle was purchased used in June of last year with about 120,000 km. It has mainly been used for development, and the annual mileage is

People use their batteries very differently. Some may only consume 10% in a day, others 50%, and some even require more than a full charge daily. So why does Tesla set 80% as the default charging limit for most users? From a battery health perspective, 50% state of charge is actually the most stable. But if a manufacturer simply told users to "keep your battery around 50%," most people would find that confusing and difficult to apply in real life. That’s why 80% has become th

You’ve probably heard EV owners throw around the phrase “ABC:  Always Be Charging.” But what does it really mean? It’s not just “plug in...

Many consumers judge the condition of a used car only by age and mileage. However, for electric vehicles, the most accurate indicator of...

Model Y: In this graph, the battery heater does not activate. The temperature rise is gradual and caused only by the thermal load from...

As many of you may already know, Tesla’s manual recommends limiting regular use of NCA/NCM batteries to 80% state of charge. The...

This method is intended to reassure owners who may be worried about BMS a079 even without visible symptoms, and to help used car buyers...

Previously, you could only review data from your most recent session . Now, we’ve expanded the feature so you can analyze battery and...

Some owners believe that the battery management system (BMS) is designed solely to maximize battery life. In reality, this is not the...

Until now, Dr.EV only provided the “Personalized Remaining Life Distance,” which is calculated based on your actual driving and parking...