To enable a BullTron battery to work on the P-Bus, it must be configured once. This involves two steps: a setting in the SMART BMS app and a firmware update via the BULLTRON app. No tools or technical experience are required — just a smartphone and about 15 minutes. Why this conversion is worth it is explained in the article Integrating a BullTron battery directly into the P-Bus.
Note Follow steps 1 through 7 in this exact order. The order is not interchangeable: the SMART BMS app must be closed before the BULLTRON app can take over the connection. There is no problem with going through these instructions multiple times.
What you need
- The battery, switched on and within range. Connection is via Bluetooth, not the bus.
- A smartphone or tablet with Bluetooth enabled. iOS and Android are both supported.
- The BULLTRON and SMART BMS apps. Both are free and both are required.
- The battery type. This can be found on the battery's nameplate or in the purchase documents and determines the update code.
1. Install both apps
Open the App Store (iPhone or iPad) or the Play Store (Android) and search for BULLTRON and SMART BMS. Tap "Install" for each and wait for the apps to download completely.
Install both, even if you will only use one of them regularly later. You can recognize the BULLTRON app by the bull's head icon, and the SMART BMS app by the round green icon.
2. Connect to the battery
Open the SMART BMS app, having previously checked in your device's settings that Bluetooth is enabled. Tap "Local Monitoring" and select your battery from the list. The name starts with BT-, followed by a sequence of numbers and letters.
3. Enter password
As soon as the connection is established, the app will display the charge level in percent. Tap "Parameter Settings" in the bottom right corner. A window will appear requesting a password: enter the digit 0 six times, i.e., 000000.
4. Set communication protocol to NONE
You are now in the parameter settings. Locate the "Communication Protocol" item, tap it, and select NONE from the list.
Afterward, close the SMART BMS app completely — do not just move it to the background; truly quit the app. As long as it holds the Bluetooth connection, the BULLTRON app will not be able to access the battery.
5. Open the BULLTRON app
Now open the second app, BULLTRON, and select your battery from the list again. Ensure the name starts with BT-. Then, tap the "System" tab at the bottom.
Warning Do not select the entry starting with JHB-. That is the wrong connection. An update started through it will not reach the intended destination.
6. Determine and apply update code
In the "System" tab, you will see several tiles. First, verify which of the two codes belongs to your battery. The assignment is based on the battery type, not the capacity — two batteries with similar ampere-hour ratings may be in different columns.
| Code MEFEJD | Code HYICVL |
|---|---|
| 100 Ah Slim Polar | 170 Ah Polar |
| 105 Ah Polar | 210 Ah Polar |
| 165 Ah Polar | 230 Ah Polar |
| 185 Ah Polar | 270 Ah Polar |
| 320 Ah Polar | 350 Ah Underseat Polar |
| 460 Ah Polar | 540 Ah Underseat Polar |
| 750 Ah Polar | 105 Ah 24 V Polar |
| 50 Ah 24 V Polar | — |
| 100 Ah 24 V Slim Polar | — |
| 230 Ah 24 V Polar | — |
You can find the exact battery type on the battery's nameplate or in your purchase documents. If you are unsure, it is better to ask before starting the update.
Tap the "Firmware Update" tile. An input field will open. Type in the appropriate code and then tap "Execute". The update will start automatically and may take several minutes.
Warning Keep the app open and in the foreground during the update and do not turn off your device. If the screen goes into sleep mode, it will interrupt the Bluetooth connection — and thus the ongoing update.
7. Restart the battery
Once the update is complete, one step remains: switch the battery off using the button, wait 10 seconds, and switch it on again. Only with this restart will the battery adopt the new firmware.
After that, it is configured for the P-Bus. The Control Unit PCU, PSL, and PSM 3 will now display battery values directly from the BMS. How to wire the battery is explained in the article Wiring the P-Bus.
Troubleshooting
| Observation | Solution |
|---|---|
| Battery does not appear in the list | Check device Bluetooth and battery switch, move closer |
| Multiple entries to choose from | Choose the entry with BT-; entries with JHB- are the wrong connection |
| Password is not accepted | Enter exactly six zeros and check for extra characters in the field |
| BULLTRON app does not find the battery | SMART BMS is still open and holding the connection — exit the app completely |
| Update aborts | Restart the battery (off, 10 seconds, on) and repeat step 6 |
| PCU does not show battery values | Check bus connection and termination, then restart the battery |
Terminology
- BMS. The Battery Management System inside the battery. It monitors every cell and maintains the charge status. What it does and doesn't do is explained in the article What a BMS does and what it doesn't.
- Firmware. The built-in software of the battery. The update brings it up to the version that includes communication with the P-Bus.
- Charge status. How full the battery is at that moment, in percent — comparable to a fuel gauge.
- P-Bus. The bus system by philippi through which on-board devices exchange data. The architecture and topology are explained in the article Understanding the P-Bus.
Typical errors
- SMART BMS only moved to the background. The Bluetooth connection remains active, and BULLTRON cannot find the battery.
- Entry with JHB- selected. It looks like the battery, but it is the wrong connection.
- Code selected based on capacity instead of type. The assignment follows the battery type; similar ampere-hour ratings say nothing about the code.
- Device put away during update. The screen turns off, the connection breaks, and the update gets stuck.
- Forgot to restart after the update. Without off-wait-on, the configuration is not completed.
- Communication protocol not set to NONE. The battery will continue to use a different protocol and remain silent on the bus.
