Stop Charging to 53.2 V – Protect Your Pylontech Batteries the Smart Way

The ServTec CAN-Bus Bridge is a plug-and-play interface designed for installers, engineers, and battery specialists who want finer control over the maximum charge voltage published by Pylontech US-Series batteries.

Installed inline with the CAN-Bus cable between the master battery and inverter, the bridge allows you to override the factory “recommended charge voltage” of 53.2 V via a built-in web interface — ideal for systems where the inverter cannot override the battery-published CVL.

What This Device Does

• Prevents your inverter from charging Pylontech batteries to 100 % SOC and 53.2 V
• Allows the Charge Voltage Limit (CVL) to be reduced (e.g. 52.2 V or lower) using a simple web interface
• Helps reduce stress on ageing batteries by lowering peak charge voltage
• Keeps cell voltages within the flat LiFePO₄ charge curve, reducing imbalance and cell swelling
• Passes all other CAN-Bus messages through untouched
  (SOC, SOH, limits, alarms, status)
• Displays live battery and system data directly from the master battery

New Firmware Features (v1.0.5+)

Built-in Wi-Fi Access Point

• No app required
• Connect directly from a computer, phone, tablet, or laptop
• Optional connection to your home or site Wi-Fi network

Large SOC Display Mode

• Dedicated full-screen SOC page
• Ideal for mobile devices and commissioning
• Displays SOC, voltage, current, and power (V×I)

Enhanced Battery Diagnostics

• System-level data decoding (ICD 2.4.x)
• Minimum and maximum cell voltage with module location
• Cell temperature extremes
• Module status (charge/discharge allowed, comms state)
• Total system capacity and module count
• Supports LV Hub and multiple groups.

Advanced CAN Diagnostics

• Per-bus CAN RX/TX counters (Battery vs Inverter)
• Optional CAN message descriptions
• Serial debug mode for engineers and diagnostics

User-Upgradeable Firmware

• Update via USB-C as new features are released

Supported Batteries

• US2000 Plus / Plus-B
• US3000 Plus / Plus-B
• US2000C
• US3000C
• US5000 / US5000-B

Also compatible with other batteries and BMS devices that emulate the Pylontech 2016 LV CAN protocol, including some JK-BMS-based systems.

When Should You Use This Tool?

Use the ServTec CAN-Bus Bridge when you want to:

• Reduce charge voltage on ageing Pylontech modules
• Avoid unnecessary full-voltage cycling
• Test system behaviour at different CVL levels
• Diagnose battery or inverter CAN-Bus behaviour
• Extend battery service life in retrofit installations

Technical Overview

• Processor: Dual-core Xtensa® LX7, up to 240 MHz
• Wi-Fi: 2.4 GHz IEEE 802.11 b/g/n
• Flash Memory: 16 MB
• Firmware: User-upgradeable

Power Options

The bridge can be powered in one of three ways:

• 5 V / 1 A USB power supply (not included)
• ServTec 48 V → 5 V DC-DC converter (available separately)
• 12–24 V DC supply via 2-pin terminal block

Package Contents

• 1 × ServTec CAN-Bus Bridge (SERV-0046)
• 1.5 m Pylontech battery CAN cable
• 1.5 m inverter CAN cable
• 0.5 m USB-C power cable

Setup Procedure (Summary)

1. Power down the inverter and batteries
2. Disconnect the existing CAN-Bus cable from the master battery
3. Insert the bridge inline between battery and inverter
4. Power the bridge
5. Access the web interface to confirm status
6. Power up batteries and inverter
7. Verify the published charge voltage has changed on the inverter

The bridge ships preconfigured with a default CVL of 52.2 V.
Lower values (e.g. 51.8 V) are supported, but SOC accuracy may reduce due to the flat LiFePO₄ voltage curve.

Important Safety Notice

Use only with well-maintained 15-series LiFePO₄ batteries.
Do not use with batteries that are damaged, swollen, unbalanced, or electrically unstable.

Warranty

This product includes a 1-year return-to-base warranty covering manufacturing defects.

Need Help With Compatibility or Setup?

Our UK-based support team can help with inverter compatibility, CAN pinouts, alternative BMS systems, and commissioning advice.

📧 [email protected]

Further Reading:

Update Instructions

Version 1.0.5 Firmware & Updater

Manual

How Victron deal with this issue within their Cerbo GX.

Firmware Changes