Surron Battery Reviver
A purpose-built bridge and diagnostic system that wakes supported Sur-Ron batteries, reads the data hidden behind the BMS, logs every session, and presents the measured state in a customer-readable recovery workflow.
Total pack voltage is not enough when one group can decide whether the original charger starts.
Why I built it
A deeply discharged Ultra Bee pack can still communicate even when it no longer behaves like a normal battery at the charge port. The original charger sees one or more groups below its enable threshold and refuses to start. A voltmeter across the whole pack cannot explain which group is responsible, how large the imbalance is, or whether the reported data is complete.
I wanted one tool that could establish CAN communication, show the evidence, preserve raw logs, teach a first-time user what the numbers mean, and keep the dangerous decisions visibly separate from the visual design.
What I built
Hardware and software that communicates with supported battery variants, tracks live RX/TX activity and exposes the battery state to the interface.
A dependency-free interface for phone, tablet and desktop with Basic, Advanced and Technician views.
Horizontal and vertical cell views, voltage thresholds, highest, lowest, average and delta—with incomplete groups kept visibly incomplete.
Individual-cell charting, pack voltage, current, temperatures, event records and CSV export for later comparison.
Support for older 4-pin Ultra Bee charge connectors and newer 6-pin Ultra Bee / Light Bee 2 variants.
Interrupting acknowledgements, complete-snapshot requirements, stale-data treatment and a non-negotiable 2.00 V product floor.
The hard part was not the graph
The difficult work was learning which CAN behavior was observed, which decode was provisional, and which data was still unknown. The interface keeps those evidence levels intact. A badge cannot become “confirmed” because a different color looks cleaner.
The BMS wake and output authorization behavior also demanded a defensive connection sequence: request a short wake, explicitly release it, then watch fresh state and current before enabling controls. If the browser or phone disappears, the next connection begins by requesting Latch OFF again.
Important: this is not a blind charger or a BMS-bypass tutorial. The system is designed to keep diagnosis visible even when recovery is blocked. Below the product's 2.00 V hard floor, the recovery command remains unavailable.
Supported launch targets
- Sur-Ron Ultra Bee, 2024 and earlier — 4-pin charge connector
- Sur-Ron Ultra Bee 2025 and early 2026 — 4-pin charge connector
- Sur-Ron Ultra Bee mid-year 2026 — 6-pin charge connector
- Sur-Ron Light Bee 2 (LB2) 2026 — 6-pin charge connector
What comes next
The immediate work is the sellable enclosure, final bridge hardware, production provisioning, authenticated cloud history, field testing across connector variants, and a launch-quality support workflow. The web interface is already functioning against the local live bridge and storing real session logs.