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Data needed for new battery integration
This page describes the values that are used in the battery emulation SW. The values can come from various sources, such as battery communication, data sheets, manual configuration, etc.
If you want to integrate a battery, this page will help you figure out what you need to be able to extract from the battery via CAN logs and such.
Unless the communication protocol is already reverse engineered and available, the minimum battery CAN communication logs needed to integrate a new battery are:
- CAN logs from a working vehicle
- Vehicle idle
- Vehicle startup
- Vehicle charging
- Vehicle completing charge
- CAN logs from a standalone battery
- (optional) CAN logs from a vehicle while driving
This data is typically matched to noted values "offline", such as reading the SOC in the instrument cluster to match it with the CAN data.
You will first have to get some hardware capable of reading the communication. Here are some examples, listed from least expensive to more expensive. Do note that more expensive tools will be easier to use, since the software provided with the tools are very user friendly. Also more expensive tools will have better timing and accuracy on timestamps.
LilyGo board (can log data in testing mode!)💲
USBCAN PCAN clone 💲 Recommended,link: https://www.aliexpress.us/item/1005006341852788.html
Raspberry PI with CAN shield 💲💲
USB2CAN Korlan 💲💲 Recommended, link: https://www.8devices.com/products/usb2can_korlan
Kvaser 💲💲💲
Peak PCAN 💲💲💲
Softing 💲💲💲
Take pictures of HV and LV connectors on the battery. Figure out the pinout with manuals found online, or behind paywalls. Add this info to wiki page for the new battery. If the wiki page for your battery does not exist yet, create a new page.
Start battery by applying 12V to it, and CAN H-L pins to a CAN reader / LilyGo. Note, on some batteries you might need to satisfy interlock or airbag / crash signals before they startup.
Get a CAN log of the battery in standalone operation. An example from start to finish can be seen here: https://github.com/dalathegreat/Nissan-Leaf-Battery-to-OBD2
The CAN-logging is available when using the TEST_FAKE_BATTERY mode. This enables easy CAN logging without expensive CAN reading hardware. When you are using this test mode, all the received CAN messages will get timestamp, ID, DLC, and data fields printed out via the Arduino IDE Serial. This can then be exported to a .txt file for later analysis. Example format:
7556 54A 8 10 0 70 2 0 0 0 2B
7558 54B 8 1 8 80 12 4 0 0 0
7560 54C 8 61 66 0 0 0 0 57 0
7590 1DC 8 6E F 8F FD C E4 E0 D1
7591 380 8 2 4 10 21 0 0 0 8D
7592 5BF 8 0 0 0 0 28 0 0 1A
7593 1D4 8 F7 7 0 0 47 46 0 BC
Note
If your serial monitor is filled with strange symbols "???!"?¤¤%" , change the baud rate in the serial monitor window from 9600 -> 115200
This table lists the typical values used. The more values available, the better. The more values directly received from the battery, the better.
The Source(s) column describes the possible origins of the value.
- Battery: The value is extracted from battery communication
- Manual configuration: The value is known based on battery make/model, inverter make/model, etc
- Estimation: The value can be estimated based on various battery information
| Value | Type | Source(s) | Comment |
|---|---|---|---|
| SOC | Mandatory | Battery | State of charge. Shall be given by the battery BMS or calculated based on verified methods |
| DC voltage | Mandatory | Battery | Total HV battery DC voltage |
| DC current | Mandatory | Battery | HV battery DC current |
| Pack max temperature | Mandatory | Battery | HV battery max measured temperature |
| Pack min temperature | Mandatory | Battery | HV battery min measured temperature |
| Maximum pack DC voltage | Mandatory | Battery Manual configuration |
The maximum allowed HV battery pack voltage |
| Minimum pack DC voltage | Mandatory | Battery Manual configuration |
The minimum allowed HV battery pack voltage |
| Pack capacity | Mandatory | Battery Manual configuration |
Total HV battery pack capacity in kWh or similar |
| Remaining pack capacity | Mandatory | Battery Manual configuration |
Remaining HV battery pack capacity in kWh or similar |
| Allowed charge power | Recommended | Battery Estimation |
The maximum allowed charge power of the HV battery. Preferably taken from battery communication, but can be estimated |
| Allowed discharge power | Recommended | Battery Estimation |
The minimum allowed charge power of the HV battery. Preferably taken from battery communication, but can be estimated |
| SOH | Optional | Battery Estimation Manual configuration |
State of health. Preferably taken from battery communication, but can be estimated |
| Cell voltages | Optional | Battery | Voltages of individual cells in the pack. Good for extra layers of safety and for judging the overall health of the pack |
| Number of cells | Optional | Battery Manual configuration |
The total number of cells in the pack. Used for tracking min/max, displaying values in the web UI properly, etc |
| Pack chemistry type | Optional | Battery Manual configuration |
The chemistry leads to different values for min/max voltages (both pack and cell), etc |
One the mandatory info has been found for the battery communuication, it can be integrated to the software. Create a battery .cpp and .h header, see the other batteries for how the structure should look like. If in doubt, contact the developers!