Inside the Tesla Battery for Electric Car

Today we are going to talk about the battery pack in the Tesla electric cars Model S, and Model X (and Model 3 soon).

For those who don’t know, Model S and Model X battery pack are identical because it’s built on the same platform.

So the battery pack is essentially a large weld aluminum box, weighs approximately 250 pounds and is compartmentalize. There is 14 different battery modules and they’re off our world from one another and in the front of your give a look at it, there is a hole in the front.

Inside the battery itself, there are 16 battery modules. The battery module use 18650 battery cells. Those are wired together - 444 of them together wired and there’s a thermal management system that runs in all battery modules to maintain the heat and the temperature inside the batteries.

There are 7104 battery cells all of them approximately 3,400 million powers of battery at 3.6 V, so that the battery pack generate approximately 85 KW of worth of energy.

With chemistry improvements, of course, and size differences in a battery cell, eventually get larger battery packs.

What is in 18650 battery, well size comparison this is your typical AA battery, and it’s 18650 battery cell.

It‘s called 18650 because 18 millimeter wide and 65 millimeter tall. So, there are 7104 of this in 85 or 90 KW battery pack.

The battery modules on the smaller battery packs have blanks in them up to the same. Cells themselves are wired with very tiny wires that act with fuses so if one of the cells go thermal for whatever reason or short out, it doesn’t affect the rest of the battery modules.

Each one of the battery modules has a circuit board called the battery management system (BMS). It’s designed to monitor all the cells in the battery pack and report that to main computer. The battery pack total weight average of 1,000 to 1,200 pounds is very big and Tesla designed it to be a structure element as part of the vehicle and that’s why it is installed from the bottom. The way it keeps the center of gravity of the vehicle very low. That’s why you don’t get a lot of body roll and it’s in excellent hands on these cars.

Compare to his mother vehicles on the market special things like GM Volt or Nissan Leaf or BMW i3 for example. They all use battery cells and they look like this and those are used to put into their own rectangular modules and then they’re put into the battery pack itself.

In the case of a Volt, it’s a T-shape because they modified in existing shape. The Leaf and the i3 both use the same kind of battery that do work in the bottom of the vehicle. However, because these manufacturers are not using cylindrical cells like Tesla did, their thermal management system is nowhere near and good.

When Nissan first came up with a Leaf, they have a lot of trouble in hotter climates like Arizona’s of the batteries are prematurely because they had no temperature management system of the overheating. If I remember correctly lithium-ion cells really want to operate about 28 degrees Celsius (28 C). So Tesla has a thermal management system which is a coolant loop that runs between all the battery modules and it’s essentially.

Keep in mind that in winter months or colder climates that Lithium icon cells don’t like to be cold, that’s why you have to some kind of thermal management system in there to maintain the batteries optimal running temperatures so that they don’t lose things like electric range and stuff. What’s nice about the Tesla vehicles is that when you have them plugged into the wall in the winter months is a you can use the app on your to do preconditioning which is basically turn on the heating system in the vehicle so that it heats up the battery pack.