About this replacement
Panasonic MX6 / SA6 Series — 3.7V Li-ion Replacement Battery (EB-BS002)
This is a 3.7V, 1000mAh Li-ion cell built to the EB-BS002 specification. It fits the Panasonic MX6, MX7, SA6, and SA7 smartphones. Swap it in when the original cell can no longer hold a usable charge through a normal day.
- MX6, MX7, SA6, SA7 fit group: These four models share the same battery bay dimensions, connector pinout, and BMS handshake protocol — all four accept the EB-BS002 cell without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the MX6 platform. The BMS accepted the cell, reported voltage correctly, and thermal cutoff behaved within normal parameters at full charge.
- First-cycle fuel gauge reset: After fitting this cell, run one full discharge to automatic shutdown, then charge uninterrupted to 100% before resuming normal use. This lets the fuel gauge IC map its coulomb counter to the new cell's discharge curve — skip this and the percentage display will drift.
Sudden shutdown at 20–30% on the MX6 after a cell swap
A new cell has a slightly different internal resistance profile than the worn cell the phone was calibrated against. Under modem transmit or screen-on load, the phone pulls current that drops the cell voltage below the BMS cutoff threshold — even though the fuel gauge still shows 20–30%. The BMS interprets that voltage sag as a dead cell and cuts power instantly. One full discharge-charge cycle recalibrates the coulomb counter and eliminates the premature shutdown. After calibration, the gauge and the actual cell voltage track together under load.
Phone stays warm near the battery during the first few charges
A fresh cell starts with higher internal impedance than a broken-in one. The charge IC pushes current into a cell that resists it more than expected, and that resistance converts some charge energy to heat. This is normal for the first two to three cycles and fades as impedance drops with use. If warmth continues past the third full charge, check that the back cover is seated correctly — trapped heat with no airflow path will sustain elevated temperatures even after the cell breaks in.