About this replacement
Samsung Galaxy A7 2017 — 3.85V Li-Polymer Replacement Battery (EB-BA720ABE)
This is a 3600mAh, 3.85V Li-Polymer replacement battery for the Samsung Galaxy A7 2017 smartphone. It fits SM-A720F, SM-A720F/DS, SM-A720S, and related variants. OEM part numbers EB-BA720ABE and GH43-04688B both cross-reference to this cell.
- SM-A720 series fit: All SM-A720 variants share the same battery bay dimensions, connector pinout, and BMS handshake protocol. This cell matches the 96.40 × 42.30 × 5.00mm form factor and the four-pin connector used across that entire model range.
- Bench tested on actual hardware: We ran this cell in an SM-A720F and confirmed the BMS negotiation completed without error codes. The charge IC accepted the cell on the first cycle and reported state-of-charge normally through the fuel gauge.
- First-cycle calibration on the A7 2017: After installation, disable fast charging in Settings and complete one full discharge-charge cycle at standard current. The fuel gauge IC in the SM-A720 reads a discharge curve to calibrate its coulomb counter — skipping this step with fast charging active pushes high current into an uncalibrated cell and delays accurate percentage reporting.
Why the SM-A720 shuts down suddenly at 20–30% after a cell swap
The A7 2017's fuel gauge IC retains the discharge curve it mapped for the original degraded cell. When a new cell with a steeper voltage drop at low state-of-charge is installed, the IC misreads remaining capacity. Under modem or display load, the terminal voltage drops faster than the IC expects, triggering an emergency cutoff before the percentage reaches zero. One complete slow discharge-to-zero and full recharge cycle overwrites the stored curve and stops the phantom shutdowns.
Phone not powering on after the replacement battery sat in storage
Li-Polymer cells self-discharge in storage, and if the cell voltage drops below approximately 2.5V, the BMS latches into a protective lockout state and blocks normal charging. The SM-A720 will show no charge indicator and appear completely dead. Connect the phone to a wall adapter — not a PC USB port — and leave it undisturbed for 20–30 minutes. The charge IC delivers a low trickle current that nudges the cell above the BMS recovery threshold; once it crosses roughly 3.0V, the BMS unlocks and normal charging resumes.