Pylontech Battery Support — US2000 / US3000 / US5000 BMS Faults & Inverter Pairing
Pylontech battery not charging, BMS communication fault, PYLON protocol pairing issues, or inverter compatibility problems — we diagnose Pylontech battery systems across all common inverter pairings. Independent battery specialists, not affiliated with Pylontech or your installer.
Most Pylontech BMS and pairing issues are resolved remotely. Tell us the battery model, your inverter brand, and what you're seeing.
Book Remote Diagnostic — from £75 → See the Solar Health PlanSafety: If your Pylontech battery shows a red fault LED or unusual heat, isolate at the DC switch before investigating.
Common Pylontech problems we diagnose
Pylontech is one of the most widely deployed battery brands in the UK — the faults we see are consistent and well-understood. Most are resolvable remotely.
Pylontech batteries don't hold their own schedule — charging is controlled by the paired inverter's TOU configuration. If the battery isn't charging overnight, start with the inverter's monitoring platform. Check that the charge window is enabled, grid charge is on, and the SoC minimum is below your current charge level.
See diagnostic guide →The inverter has lost communication with the Pylontech BMS. Pylontech batteries use the widely-supported PYLON protocol over RS485 or CAN. Common causes: wrong protocol or baud rate selected on the inverter, damaged communication cable, or DIP switch addressing errors in a multi-module stack. Diagnosable remotely from inverter event logs.
See diagnostic guide →Pylontech battery at 100% but the inverter isn't drawing from it. Check the inverter's discharge schedule and minimum SoC threshold. If a BMS protection trip is active (e.g. cell imbalance, over-temperature), the battery will hold off discharge until cleared. Check Pylontech LED status — flashing amber often indicates a cell balance issue.
See diagnostic guide →Pylontech batteries work with open-protocol hybrid inverters (Solis, Sofar, Victron, Lux, SolaX) but not closed systems like GivEnergy or Fox ESS. The inverter must be set to use the correct battery type (Pylontech/PYLON, not generic lithium). A mismatch between expected and actual battery capacity — common when adding modules to an existing stack — can also cause pairing failures. We verify the full communication and capacity configuration.
See diagnostic guide →The US series are low-voltage (48V) modules (US2000C: 2.4kWh; US3000C: 3.5kWh; US5000: 4.8kWh). Common issues in multi-module stacks: one module triggering protection and shutting down the whole bank, incorrect master/slave DIP switch setup, or cell imbalance in older units reducing available capacity. LED status patterns on the front panel indicate which module has faulted.
See diagnostic guide →The Pylontech Force H2 is a high-voltage battery system (up to 614V) used with compatible HV inverters. Common issues: insulation fault on first commissioning (loose HV bus bar connection), BMS master/slave assignment errors in multi-tower setups, or inverter HV battery type selection mismatch. Requires HV-qualified engineer for physical inspection.
See diagnostic guide →EPS/backup mode is controlled by the paired inverter, not the Pylontech battery. If backup power failed during a grid outage, the inverter's EPS circuit may not have been commissioned, the backup load may exceed the EPS output rating, or the Pylontech battery may have had a BMS protection active that prevented discharge.
See diagnostic guide →What we do for Pylontech battery owners
Remote Pylontech Diagnostic
We review inverter logs, PYLON protocol communication data, and battery BMS error history to find the fault — whether it's in the battery, the inverter, or the communication layer.
Inverter Pairing & Configuration
We configure the correct PYLON protocol, baud rate, battery capacity, and module count on the paired inverter. Works with Solis, Sofar, Victron, LuxPowerTek, SolaX, and other open-protocol inverters.
On-Site Pylontech Inspection
RS485/CAN cable verification, DIP switch inspection, multi-module stack health check, and module replacement assessment. HV-qualified engineer available for Force H2 systems.
Pylontech datasheets, manuals & warranty PDFs
Download datasheets, installation manuals and warranty documents for Pylontech battery systems and compatible inverters. Self-hosted and always current.
Pylontech fault code index
Seeing an error code from your Pylontech battery? Our fault code index explains what each code means, common causes, and safe next steps.
About Pylontech batteries — what you need to know
Pylontech is one of the world's largest LiFePO4 battery manufacturers and has one of the highest install bases of any battery brand in the UK residential solar market. Their most widely deployed products are the US series — low-voltage (48V) stackable modules: US2000C (2.4kWh), US3000C (3.5kWh), and US5000 (4.8kWh). These pair with most hybrid inverters via the PYLON RS485 or CAN protocol. For higher-capacity systems, the Force H2 provides a high-voltage architecture. US series batteries are typically rated IP20 for indoor installation with a 10-year warranty.
Pylontech batteries are inverter-agnostic by design, using the PYLON protocol that is supported by most major hybrid inverters. Common UK pairings include Solis, Sofar, Victron, LuxPowerTek, and SolaX inverters. GivEnergy and Fox ESS are closed battery systems and are not compatible with Pylontech. Because the schedule is held by the inverter, most charging problems are inverter configuration issues rather than battery faults. The most common queries: Pylontech US2000 not charging, Pylontech BMS communication fault, Pylontech US3000 LED status, US5000 pairing issue, and Pylontech not discharging. STS provides independent support — not affiliated with Pylontech.
Pylontech battery questions answered
Start with the paired inverter's monitoring platform — Pylontech batteries follow the inverter's schedule, not their own. Check the charge window is enabled, grid charge is on, and the SoC minimum is below your current battery level. If the schedule looks correct but charging still doesn't happen, look for a BMS communication fault in the inverter's event log — this stops the inverter from reading the battery's state.
Pylontech US series modules have front-panel LEDs indicating state: solid green = normal operation; flashing green = charging or discharging; amber = warning (commonly cell imbalance or high temperature); red = fault (often protection trip). When you have a stack of multiple modules, each module has its own LED — an amber on one module while others show green usually points to cell imbalance in that unit.
Pylontech uses the widely-supported PYLON protocol over RS485 or CAN bus, making them compatible with many open-protocol hybrid inverters. Common UK pairings include Solis, Sofar Solar, Victron, LuxPowerTek, and SolaX. Important: GivEnergy and Fox ESS are closed battery systems — they only work with their own batteries, so Pylontech cannot be paired with these brands. The inverter must be set to the correct battery type (Pylontech or PYLON protocol) — using generic lithium mode is a common commissioning error that causes BMS faults.
All three are 48V low-voltage LiFePO4 modules. The US2000C provides 2.4kWh per unit; the US3000C provides 3.5kWh; the US5000 provides 4.8kWh. Multiple units can be stacked to reach the required total capacity. All use the same PYLON protocol for inverter communication. For a given total storage target, fewer US5000 modules are needed compared to US2000C — making the US5000 more common in larger installations.
STS supports all major inverter and battery brands. If your Pylontech battery is paired with a specific inverter, visit that brand's page for inverter-specific guidance.
Browse all supported brands →Ready to fix your Pylontech system?
Tell us your Pylontech model, the inverter it's paired with, and what you're seeing. We'll diagnose the fault — usually same day.