Scope and operating assumptions
This note examines current feedback in a DC installation containing a charger, a lithium battery and parallel loads. It is relevant when reviewing auxiliary-power integration around Schneider Electric equipment, without asserting that any named product implements this charging algorithm. The documented architecture accepts either combined charger-output measurements or battery-monitor feedback. Applicability must be established for the actual controller; no JTM charging settings are specified.
Working principle and control logic
In the documented controller, absorption can finish when sensed charging current remains below its configured termination threshold for a qualifying duration. A maximum-duration condition provides another route to the subsequent charging stage. The documentation also describes a configuration that disables current-based termination.
For a single DC bus, define charging as positive into the battery. Current conservation then gives I_battery = I_chargers - I_loads, with every current expressed in amperes. This accounting statement assumes all relevant branches are included. A load consuming charger output makes charger current greater than net charging current. Consequently, using charger output alone can conceal a declining battery-acceptance current; battery-monitor feedback represents a different measurement boundary. A negative battery-current value means net discharge under this convention. It does not, by itself, predict a controller transition: treatment of signed values, validity checks and operating mode remains implementation-specific.
Parameters and interfaces
The termination threshold is a current in A; qualification duration and absorption timeout are time quantities whose units must match the controller documentation. The feedback-source setting determines which measurement enters the comparison. Battery current, aggregated charger current and individual charger channels must not be interchanged. No threshold, duration, network protocol or register address is prescribed here.
Verification and fault diagnosis
Compare existing logs only after checking current polarity, sensor location, included branches and timestamp alignment. A difference between current channels can be consistent with parallel consumption, but is not proof: omitted branches, offsets and asynchronous samples also require consideration. Examine the recorded stage-transition reason to distinguish timeout from current-based termination. A current trace alone cannot establish that reason.
Limitations
The discussion is an interpretation of a documented architecture, not a universal charger specification. A low-current transition does not independently prove cell balance or battery health. Thresholds and voltage limits require product-specific evidence. Review logged data and documented configuration only; no live wiring, protection bypass or improvised battery tests are instructed.