About this replacement
Samsung Galaxy Core Max — 3.85V Li-ion Replacement Battery (EB-BG510CBC)
This is a 3.85V, 2000mAh Li-ion replacement battery for the Samsung Galaxy Core Max, compatible with SM-G5109, SM-G510F, Galaxy Core Max Duos, and related variants. It replaces OEM part EB-BG510CBC directly. Use the product dimensions — 54.90 × 50.60 × 6.00mm — to confirm fitment before installation.
- Core Max and Duos compatibility: The SM-G5109 and SM-G510F share the same battery bay dimensions, connector pinout, and BMS handshake protocol — both accept the EB-BG510CBC cell without modification.
- Bench tested on actual hardware: We cycled this battery on the SM-G510F platform and confirmed the BMS negotiated correctly with the charge IC, reaching full cutoff at 4.35V with no false-full triggers.
- First-cycle fuel gauge recalibration: After fitting this cell, disable fast charging and run one full discharge down to auto-shutdown, then charge uninterrupted to 100%. This gives the fuel gauge IC a clean reference curve against the new cell before high-current charging begins.
Why the Galaxy Core Max reports wrong battery percentage after a cell swap
The Core Max uses a coulomb counter in the fuel gauge IC that was calibrated against the discharge curve of the original cell. A new cell has slightly different internal resistance and voltage-versus-capacity behaviour. Until the IC recalibrates, the percentage reading lags or jumps — the hardware is not faulty. One full discharge-charge cycle with fast charging off writes a new baseline to the fuel gauge and stabilises the percentage readout.
Sudden shutdown at 20–30% on the replacement cell
This happens when the cell voltage drops sharply under combined modem and display load — what engineers call a voltage cliff. The phone's protection circuit triggers a shutdown before the percentage display reaches zero because the cell cannot sustain the voltage rail under peak draw. It is not a defective battery — it is the fuel gauge IC reporting a percentage that does not yet map accurately to this cell's load curve. Run two full unconstrained discharge-charge cycles and the shutdowns will stop as the IC learns the new curve. If the problem persists after three cycles, check that the battery connector is fully seated and the contact pins are clean.