About this replacement
Samsung Galaxy Core Advance SM-G3812 Series — 3.8V Li-ion Replacement Battery (EB585158LC)
This is a 3.8V, 2100mAh Li-ion replacement battery for the Samsung Galaxy Core Advance series, covering SM-G3812, SM-G3818, SM-G3819, and SM-G3819d. It uses OEM part number EB585158LC and slots directly into the original battery bay. Capacity figures come from the product specification, not estimated from web sources.
- SM-G3812 / G3818 / G3819 series fit: These models share the same battery bay dimensions, 3.8V nominal voltage rail, and EB585158LC connector pinout. The BMS handshake across this range uses the same thermistor and identification lines, so one cell covers the entire group without modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on SM-G3812 hardware. The BMS accepted the cell without fault flags, the charge IC ramped to full current normally, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
- Fuel gauge recalibration on first install: After fitting this cell, run one complete discharge-charge cycle with fast charging disabled. The Galaxy Core Advance fuel gauge IC is calibrated to the old cell's discharge curve — skipping this step causes the reported percentage to lag or jump until the coulomb counter resets against the new cell's actual capacity.
Sudden shutdown at 20–30% on the Galaxy Core Advance after a cell swap
The Galaxy Core Advance modem and display draw a combined current spike that the fuel gauge IC cannot predict accurately on a freshly installed cell. When the IC's internal model drifts from the real cell voltage curve, it misreads remaining capacity and allows the phone to run until the cell voltage drops below the BMS cutoff — which happens earlier than the reported percentage suggests. This is a coulomb counter drift problem, not a defective cell. One full discharge from 100% to automatic shutdown, followed by an uninterrupted charge to 100%, resets the IC's model against the new cell curve. After that single cycle, the shutdown threshold and reported percentage align correctly.
Phone warm near the battery compartment during the first few charges
A new Li-ion cell has slightly higher internal impedance than a broken-in cell. The charge IC on the Galaxy Core Advance pushes a fixed current regardless, so the new cell dissipates more heat during the first several charge cycles as impedance drops with use. This is normal and typically resolves within three to five full charge cycles. If the back cover stays hot to the touch past cycle five, check that the replacement cell dimensions match — 58.19 x 50.33 x 5.55 mm — as an oversized cell pressing against the cover traps heat against the charge IC. Measure cell thickness before assuming a charge IC fault.