The Truth About Tesla Model 3 Batteries: Part 2

Welcome to another video from Two Bit da Vinci, this is

part

2 of our series on the

truth

about Tesla Model 3

batteries

. First, we need to correct something from Part 1. When we display prices per pound, we accidentally divide the price into kg times 2.2 instead of multiplying it. Here are the corrected prices. While our unit conversion mishap didn't result in the loss of a $125 million NASA orbiter or anything, we felt bad anyway. Rest assured, we will do better in the future! Well, in the first

part

we discussed the raw material supply chain and the manufacturing of battery cells for Tesla's 2,170 cells.

Today we will continue here and discuss how Tesla takes these 2170 cells and creates their world-class battery pack modules. First of all, it is always best to start with

batteries

in parallel that form a brick. This Long Range Edition brick contains 46 batteries, while the base

model

will have 31 batteries. This is so that any failure in a battery does not affect the core voltage of the brick. You'll just lose that amount of capacity and range. The next brick is inverted and added to the first brick in the series. All the batteries that make up a brick are connected in parallel using a bus bar.

You'll notice that a thin filament is actually all that connects a battery to this bar. The reason is that due to its thin gauge, it actually acts as a fuse. If too much current flows, either during charging or discharging, the fuse will overheat and break. This will remove the battery from the rest of the brick and isolate it from any further damage or potential thermal runaway events. For added protection, Tesla 2170 batteries have 3 very small holes that act as vents to discharge electrolyte and prevent pressure buildup and possible explosion. There is also a “blue goo” that is added to add even more stability to the package and prevent cascading failures.

Speaking of thermals, we mentioned that one of the benefits of small cells is the ability to cool each battery better. That's where the cooling manifold comes into play. Tesla has a patent (US20110212356A1 (https://patents.google.com/patent/US20110212356A1/en)) for a cooling manifold assembly for its battery packs. The cells are covered by a thermal interface material, which is a poor electrical conductor, but a good thermal conductor, allowing good contact between the aluminum battery case and the collector. A mixture of water and glycol coolant is pumped through this manifold, where heat can be transferred from the batteries, just like liquid cooling your PC or a conventional liquid-cooled gas engine.

What is special about this design is the wave slots, which allow maximum contact between the battery cells above and below the collector, with minimal increases in flow resistance. In the case of the prismatic batteries in the BMW i3 or the pouch batteries in the Chevy Bolt, this cell-by-cell cooling is not very easy to achieve. One limitation of this design is that the coolant will be colder when it first enters and warmer near the exit, causing slightly uneven cooling of a few degrees. That is why the corrugated design is so important, as it does not substantially reduce the flow rate.

This means that hot coolant can be pumped to the radiators more quickly. Keeping batteries cool while charging and discharging is one of the most important factors for safe operation and also maximizes the life of lithium-ion batteries. You'll notice that there is no radiator in the front of a Model 3, like in gasoline cars, and that's because electric vehicles don't need that level of cooling for the engine. However, if you look down at the front bumper, you'll see the vents that house the battery thermal management system and the powertrain radiator. These motorized vents can be opened and closed to minimize air resistance while still providing airflow to the radiators when needed.

This can only reduce temperatures to the level of the surrounding ambient air, but for particularly spirited driving, super-fast charging or very hot days, the refrigerant can be transported through the air conditioning system via plate heat exchangers to even better cooling. The Tesla Model 3 has a new simplified 4-module battery system. Interestingly, they are not all the same size: the outer modules have 23 groups of cells, while the two inner modules have 25. Again, this is the beauty of a small cell design, which gives them this type of flexibility. A recent teardown of a Model 3 battery pack by Jack Ricard reveals that each cell block has 46 batteries in parallel, coupled to 23 or 25 other blocks in series.

This means that a Tesla Model 3 Extended Range has 4,416 batteries and weighs approximately 1,050 pounds. So the entire Model 3 battery pack has a capacity of about 80 kWh and a density of (1054 lbs = 478 kg _____ 80 kWh = 80,000 Wh / 478 = 167 W/kg Remember the concept of battery swapping in 5 minutes that Elon showed a few years ago "Where a Model S could get a robot to change battery packs in less time than a gasoline car could refuel? Well, it seems that idea is dead, because the design of the Model 3 batteries, with their solid aluminum bottom plate, won't allow this functionality, but that's why Tesla has been investing in DC fast chargers, and their NCA chemistry, combined with the brilliant cooling system and power sharing. air conditioning, means Tesla Model 3s should charge quickly with few thermal bottlenecks.cooling system, the second factor is Tesla's world-class Battery Management System or (BMS).

The BMS tracks the voltage at the cell level, to ensure that the batteries are charged and discharged evenly. It also monitors battery block temperatures through strategically placed thermocouples, and it's something Tesla now has more than a decade of experience with. There are individual BMS for each of the four battery modules. One of the big concerns with large lithium-ion battery packs is that some individual cells do not discharge with the rest. The system then reports low rank and accepts a charge. But when this nearly full battery accepts a charge, its voltage will begin to build up and cause degradation and could even explode.

The BMS monitors this to ensure that all cells are fairly uniform and have greater protection with their individual battery fuses. Jack Rickard reported voltages within one hundredth of a volt between all the bricks of a Model 3 module. This is quite impressive and a true testament to this crucial system in the Tesla Model 3 battery pack. On the back of the battery system you will notice a small hump. Tesla affectionately refers to this as the "Penthouse." To further optimize the Model 3 manufacturing process, all battery-related systems for the entire vehicle are housed in this compartment. In previous

model

s like the S, the different AC-DC inverters and other electronic components necessary for the safe operation of the battery were distributed in various areas of the car.

But now, for the Model 3, this entire package and Penthouse are fully assembled at the Gigafactory and shipped to Fremont, where they can enter the Model 3 more quickly and with fewer hours of assembly required. This is a small innovation, but it really pays dividends when the Model 3 is mass produced. So another question we always ask ourselves is, my cell phone battery only lasts about 2 years before it starts to break down, surely Teslas must have the same problems. Fortunately, the answer is no, and the reason is two-fold: 1. Most electronic devices, such as laptops and smartphones, use LCO or lithium cobalt oxide chemistry because they provide high density, while which suffer the disadvantage of a lower life cycle.

Most people only keep cell phones for a few years, and manufacturers have decided that being small and energy dense is more important than being durable. The second reason is that laptops and smartphones are charged to 100% and are also allowed to discharge to 0%. This extreme state of charge and depth of discharge can really degrade the battery quickly. Again in the case of your smartphone, it is more important that it lasts 12 hours and not 10, so it should last 4 years instead of 2. The Tesla Model 3 will help you charge and discharge at the best level for greater longevity. If you want your batteries to last as long as possible, charge them to about 80-90% of their capacity and only discharge them to about 30%.

If you're going on a long road trip, of course, you can charge to 100% on occasion, but when your trip is beyond your reach, you should always try to charge at the recommended level. In the Model 3 interface, the only user-adjustable setting is the charge status meter. A slider lets you adjust how close to 100 percent you want the car to charge. Just remember to leave this where it is recommended, unless you know you have a long trip ahead of you. Remember that a battery's voltage changes depending on its charge. When fully charged, a 2170 cell has a voltage above 4 volts, while fully discharged, only about 3.

Also, if you remember from part 1 where we talked about the expansion and contraction of the hybrid graphite anode from charged to downloaded, it is again It is best to avoid extremes. This user-adjustable load level has created some confusion and questions that we want to clarify. We were asked if the base model 3 and the extended range car actually have the same battery packs, and depending on the price, the extra range is unlocked via software. This question arises because there were reports that Tesla unlocked additional range for people in Florida fleeing Hurricane Irma. The story is this: a few years ago, Tesla was selling 75 kWh battery packs at a lower price and limiting the car's charging level to just 60 or 70 kWh.

The idea was that this would make a cheaper car possible and also present Tesla with an opportunity for additional sales. You have to remember that they weren't making the Model 3 yet and they were getting creative when it came to selling cars. So by unlocking the maximum range option, or in the case of Hurricane Irma, Tesla can activate a digital switch and set the car's state of charge meter to maximum. But don't worry, there's no such trickery in the Model 3. The Model 3 has two different battery packs, one with 50 and one with 75 kWh of usable capacity. There is no software magic at play here.

So, with incredible battery cooling, a state-of-the-art battery management system, and 10 years of experience, how long will your batteries last? Historical Tesla battery data suggests a range of 95% after 50,000 miles and 90% after 150,000 miles. That means your 310-mile extended range Model 3 will travel 279 after 150,000 miles. That's after 11 years of driving 13,500 miles a year. But the news is even better, because that historical data includes older battery packs. Our good friend Ben Sullins from Teslanomics is a data scientist and has put together some real numbers for Tesla around the world. If you haven't seen his channel, we recommend you visit it! He took the original Google Sheet, which was completed by Tesla owners around the world, and presented it in a great visual representation.

Links to the original Google Spreadsheet and Ben's site will be provided in the video description. (https://docs.google.com/spreadsheets/d/t024bMoRiDPIDialGnuKPsg/edit#gid=1710185683) (https://

tesla

nomics.co/what-is-the-lifespan-of-a-

tesla

-battery-and- how-long-will-it-last?/) Ben's website allows you to sort by kilometers or miles, or charge cycles, or age of the vehicle, and filter by different regions. You'll notice that all the data fits together quite well and that almost all vehicles seem to fit in the 90% range that remains after the 150,000 mile curve. There are some outliers that have dropped to around 85% of range remaining after just 30,000 miles, and that's what we wanted to break down below.

We've read a lot of articles about some Tesla owners needing battery replacements, so we thought we'd break down the cars that needed new batteries from this data. Filtered in this way, it reveals that around 6% of the cars needed a battery change, either due to some failures or a possible excessive loss of autonomy. What we found was interesting: almost all Teslas that needed a replacement battery were manufactured in 2013 or earlier. Cars that were made more recently do not seem to haveno problem, according to this revealing but limited data. Additionally, every single car that needed new batteries had battery changes within 8 years and 100,000 miles. (Show image for standard battery and extended warranty.) We think this is the most revealing information of all.

Tesla will have some bad battery packs, it is almost impossible to remove them completely. All it takes is a few bad cells, a few bad solder joints, or bad sensors to cause potential problems. This has to be the biggest downfall of Tesla's 2170 cell strategy. When you have to create a set of more than 4000 batteries, some errors are bound to arise. But here's the good news: If you have a faulty battery, it will likely be fixed within the warranty period. Tesla knows this and offers the warranty accordingly. Plus, their process and mastery are only getting better and Model 3 owners are likely to get the best results of any Tesla to date.

Keep in mind that gasoline cars are not perfect either. We have the Lemon Law that allows owners to return problematic cars in full. There are also thousands of reports of cars needing new transmissions or engines well below 100,000 miles. At the end of the day, it is a designed and manufactured product and, as human beings, we have never made anything perfect and we never will. What is more important is that failure rates are low and that companies rise to the occasion with great guarantees. Tesla is doing well on both accounts. The next biggest question we get is about cold weather performance.

So why is cold weather such a big concern for electric vehicles? Well, the reaction that occurs inside those lithium-ion batteries is chemical and depends on environmental factors such as temperature. Therefore, the battery thermal management system is also crucial in this case. One thing to note is that for the Model 3, Tesla has ditched the dedicated battery heater. Instead, they have chosen to heat the coolant using waste heat created by the electronics and propulsion systems. That includes the electric motor and the DC-AC inverter. So the battery system and the powertrain system share the same coolant circuit. This architecture makes the Model 3 coolant system more simplified and efficient than previous models.

Unlike cooling a battery, where the coolant passes through the air conditioning stack heat exchanger or source radiator, when heat is needed, the coolant is pumped through the powertrain cooling system. You may be wondering what happens when the car is parked and not running. Turns out it's the same process, only now, electricity is intentionally wasted in the powertrain and inverter, in order to generate heat. This heat is collected by the coolant and pumped through the batteries. Your Model 3 can be programmed to keep the batteries warm in this way, until the charge level drops to 20%. But heating the batteries in the cold is not the only drawback of electric vehicles.

There's also the passenger cabin to contend with, and this is where petrol cars have a strange advantage. Internal combustion cars are so inefficient that around 80% of the gas they burn is wasted as heat. This waste heat makes heating the cabin incredibly easy and is a rare advantage that electric vehicles simply don't have. Tesla AC electric motors have an efficiency of between 80 and 90%. So what should Tesla do? They could have simply installed a simple, inefficient resistive heating element, like the one found in Chevy Volts and Nissan Leafs. But they really thought about this and filed a special patent. (US US20100025006A1) (https://patents.google.com/patent/US20100025006?oq=20100025006) Their patent describes a system in which waste heat from each system that requires liquid cooling, including electronic components and the powertrain , is used to heat the cabin, rather than simply discarded.

And they also have a conventional resistive heater, but it needs to run less because of the heat pump system. Using electricity to generate heat is a very expensive operation and in most electric vehicles, in sub-zero temperatures, range can be reduced by around 50% due to heating requirements. With Tesla's clever waste heat pump, the range reduction will probably be closer to 30%. So your 310-mile Model 3 will have about 200 miles of range. This figure is highly dependent on temperature, so find out how cold it is where you live and ask Tesla specialists to get the best information possible. Let's put this in a little context.

In sub-zero temperatures, many gasoline cars won't even start. As long as it's in your Model 3, you'll be fine, albeit with reduced performance and range. Additionally, you've probably seen outlets outside restaurants and grocery stores in places with freezing winters, for gasoline cars to plug in and run an engine heating pad. This pad keeps the engine warm enough to spin when starting. In the future, when we have millions of electric vehicles on the roads, it is very possible that we will have a similar situation where electric vehicles plug in to keep their batteries warm and charged while you visit your destination.

And in many places these electrical installations already exist. A couple of things you can do to extend your range in cold weather is to turn the heater down to 60 degrees, don't turn on the seat heaters, and make sure you charge them as often as possible. Just remember that you have a finite amount of energy and it's up to you to balance range with comfort. Oh, and if the batteries are cold, that will also reduce the regenerative braking rate. This is again because, in cold climates, the inside of lithium-ion batteries is stronger and they cannot react as quickly to convert electrical energy into chemical potential in the battery.

So when you first start the regenerative braking will be greatly compromised, but as the system warms up the performance and regenerative braking will decrease. Here's some data from Canadian Tesla owners, showing how much they've driven and how much of their original range they have left. You will see that there is not much effect and the amount of charge remaining after hundreds of thousands of miles is quite surprising, close to 90%. https://docs.google.com/spreadsheets/d/t024bMoRiDPIDialGnuKPsg/edit#gid=1710185683 Our advice: If you live in very cold climates, you will probably want to get AWD for extra traction and also Long Range Battery for better range in Cold climates.

That covers cold-weather operation, but what about storage? Is there any risk of damaging your electric vehicle if it remains exposed to the cold? The answer is really no. The problem is not in the steady state, the problem is forcing electrons and ions to flow in these cold climates. That said, the Tesla owner's manual states that these cars should not be exposed to temperatures above 140°F (60°C) or below -22°F (-30°C) for more than 24 hours. So know your region and if in doubt, consult Tesla experts before making any decisions. So with Tesla's BMS and heating magic, you can be sure your batteries will perform effectively for years to come.

If you live in a very warm climate the information is much simpler. The BMS will keep the batteries within comfortable limits, using the AC circuit if necessary. Also, unlike the 30% drop in rage in the cold, turning on the air conditioning to cool the cabin and batteries should only reduce range by 5-10%. So let's wrap this up by reiterating a few points: 1. Tesla is about to mass produce electric vehicles and lithium-ion battery packs on scales never seen before. In response to their success, other established automakers will also make more and more electric vehicles, and this will put incredible pressure on the battery raw material supply chain.

A study conducted by the University of California at Berkeley in 2011 states that with available lithium reserves alone we could produce one billion 40 kWh battery packs. If Tesla's packages are twice that size, it would still be 500 million cars from reserves alone. Other materials such as cobalt and nickel will become increasingly critical and the future is less certain. Everything has a cost, and while Teslas don't directly pollute - stay tuned for a future video on how clean EV emissions really are - they do have other environmental costs. As an engineer, I wish there was an easy answer to all of this, but unfortunately in the real world, things are rarely that simple.

A pure electric vehicle future will require, at current technological levels, large-scale mining operations for some quite exotic materials, in some conflict zones around the world. But that's why brilliant chemists around the world are working on new battery recipes with lower environmental impact and higher performance. We'll need continued improvements in lithium-ion batteries, but we'll also need a crazy, game-changing breakthrough in energy storage that finally sounds the death knell for gasoline cars once and for all. There are future technologies, like solid-state batteries, that will become more widespread, and who knows, maybe there's something else we haven't thought of yet.

But it's a chicken-or-egg situation, where battery research is small because EV sales are small. Electric vehicle sales cannot increase until battery research and development increases. Then Tesla decided he couldn't wait any longer and took matters into his own hands. Tesla has already started stealing sales from premium cars like the BMW 3 Series, and will continue to do so in the future. They have moved this gigantic industry forward, against such strong inertia, and we can safely say that the future is proving to be very exciting. Thank you very much to those of you who have made it to both parts of this video!

Thank you to all our new subscribers and we also wanted to let you know about our Patreon page. We've spent over 100 hours researching this two-part series, 100 hours of 3D modeling and rendering, and another 30 hours of video editing. This takes a lot of time and we do it at the expense of sleep after our daily work. It's simple really, we want to create more content for you, but we need your help! If you like us a little, we hope you'll give it a thumbs up and subscribe. But for some strange reason, if you really LOVE us, check us out on Patreon and consider becoming a patron.

If we've helped you with your Tesla decision, we hope you'll consider using our Tesla referral link. If you don't want a Tesla or have more questions about all of this, that's okay too! Whatever question you have, you're probably not alone. We are two little da vinci, thanks for watching!