1. How to diagnose
You need some App/Tools to read CAN bus data related to the HV Battery. There are some Tools/Apps in Market. Please feel to contact us. We will recommend you some good App/Tool. Its really good to read data before removing/opening HV Battery Pack. (dropping HV Battery Pack). Please take photos/screenshot and share with us. We will be happy to help you which module has an issue.
Depend on Tool/App, you might need OBD Diagnostic cable for particular model/year, OBD Bluetooth Adapter etc.
2. How to remove
Disablement High Voltage
- Follow Vehicle HV Disablement Procedure
- Follow safety procedure from OEM related to car/model
- Procedure could vary
Take down the HV Battery
Remove Top Plastic Cover (Battery Insulation Blanket)
- Check if you see any sign of water below plastic cover.
Remove bolt which holds top cover of battery pack
There are mica sheets on top of each battery Module
There are coolant hoses inside battery pack
How to drain the battery
It could be drain out the battery with Toolbox or other ways. Initiate battery drain process.
3. HV Battery Pack Architecture
Pack
Tesla's High Voltage Battery pack is made up with 16 Modules in series. 1 Module gives approximately 24 Volts (16 Module * 24 Volts = 400 Volts total).
Where are module located/numbering?
- Module 1 is located on the left side at the back.
- Module 7 is located on the left side at the front.
- Module 8 and 9 are located very front (8 on bottom and 9 on top)
16 Module Pack Architecture
| 9 | ||
| 8 | ||
| 7 | 10 | |
| 6 | 11 | |
| 5 | 12 | |
| 4 | 13 | |
| 3 | 14 | |
| 2 | 15 | |
| 1 | 16 |
14 Module Pack Architecture
| 7 | 8 |
| 6 | 9 |
| 5 | 10 |
| 4 | 10 |
| 3 | 12 |
| 2 | 13 |
| 1 | 14 |
Module
A module is made up with bricks.
There are 6 bricks in 1 module. Module has approximately 24V (6 Bricks x 4 Volts). Module is made up with 444 individual cells.
Bricks
Brick is a group of cells electrically connected in parallel.
85kWh Battery pack
Brick is made up with 74 cells connected to the same plate in parallel.
When you diagnose via some Tools/Application. They call it cells however, its brick.
Cell
Cell is smallest component in Battery Pack. HV Battery module is made up with multiple battery cells connected in series.
A fully charged cell voltage is a little over 4 Volts and empty little over 3V.
There are 18650 cells inside battery pack. Cells are cylindrical in shape with 18mm diameter, 65mm length/tall and 47 grams weight. Cell stores up to 3500 mAh. Cells can be charged as high as 4.2V and discharged as lows as 2.5V.
Values are different depend on battery generation/model. Please contact us to get to know more for your model.
Cell Material: lithium-ion
4. Most common Failures
BMB Module
It is located outside the battery pack. Some of components could be corroded because of moisture/water ingress and it get bad connection.
Which Tools need?
Need battery bench, which could hold around 1000 kg. HV Battery could wight around 600 kg.
Gloves, PPE, Safety Glasses, Isolated Tools. You could check tools from KamasaTools
Sources Tesla
