No Bluetooth BMS? Here's How to Track Your Lithium Bank | PYS Tech Talk
July 17, 2026 · 6 min · 2K views
What this video covers
Monitoring the state of charge of a lithium battery bank without a Bluetooth-enabled Battery Management System (BMS) requires installing a shunt-based battery monitor.Watch Lithium batteries maintain a steady voltage throughout most of their discharge cycle, making it impossible to accurately infer remaining capacity from voltage readings alone, unlike lead-acid or AGM batteries.3:02 To capture all current transactions, the battery bank must be electrically isolated from the charging sources and DC loads.1:20 Install a dedicated battery busbar for the lithium bank and a separate charging busbar for solar arrays, alternators, and chargers.1:13 Place a shunt between these two busbars to act as a single choke point for all energy entering or leaving the system.0:52 The battery monitor connected to this shunt tracks the net current, providing an estimate of the bank's capacity.1:11 This configuration ensures that all power draws and charging inputs are accounted for, regardless of the BMS capabilities.5:09
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