About this replacement
BLU Dash JR K / D140K / D141K — 3.7V Li-ion Replacement Battery (C654405140T)
This is a 3.7V, 1000mAh Li-ion cell that replaces the original battery in the BLU Dash JR K, D140K, and D141K smartphones. It matches the OEM part number C654405140T and fits within the original battery compartment at 64.42 × 43.75 × 4.62mm. Capacity is 1000mAh (3.7Wh), identical to the factory spec.
- Dash JR K / D140K / D141K compatibility: All three models share the same battery bay dimensions, 3.7V single-cell architecture, and connector pinout — which is why one cell covers the entire variant group without modification.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on a D141K unit. The BMS accepted charge current without fault, held voltage through screen-on and modem-active loads, and cut off cleanly at the low-voltage threshold.
- Fuel gauge recalibration after install: After fitting this cell, run one complete discharge down to automatic shutdown, then charge uninterrupted to 100% before using the phone normally. The Dash JR K's fuel gauge IC is calibrated to the old cell's discharge curve — skipping this step causes the percentage counter to read inaccurately for the first several days.
Sudden shutdown at 20–30% on the replacement cell
This happens because the fuel gauge IC still holds the discharge curve from the old, degraded cell. When the new cell hits a voltage that the old curve mapped to 20–30%, the IC tells the OS the battery is critically low and triggers an immediate shutdown — even though usable charge remains. The fix is one full calibration cycle: discharge to auto-shutdown, then charge to 100% without interruption. After that cycle, the coulomb counter resets its endpoint references to match the new cell.
Phone won't power on after the battery sat in storage
Li-ion cells self-discharge in storage, and if the voltage dropped below roughly 2.5V the BMS will have entered lockout mode to prevent cell damage. The phone will show no response — no boot logo, no charge indicator. Connect the phone to a wall charger (not a PC USB port) and leave it for 15–20 minutes without pressing the power button. The charge IC needs to trickle current into the cell until it clears the BMS recovery threshold, typically around 3.0V, before the phone will respond.