About this replacement
Samsung Galaxy Ace GT-S5830 Series — 3.7V Li-ion Replacement Battery (EB494358VU)
This is a 3.7V, 1350mAh Li-ion replacement cell for the Samsung Galaxy Ace GT-S5830 and related variants including the GT-S5830T and Galaxy Cooper. It replaces OEM part EB494358VU. The battery fits the same slot, uses the same connector, and communicates with the phone's charge IC without modification.
- GT-S5830 family fit: The GT-S5830, GT-S5830T, and Cooper variants share the same battery bay dimensions (57.50 × 42.50 × 4.80mm), voltage rail, and three-contact connector. One cell covers the full range because the BMS pinout and charge termination voltage are identical across these models.
- Bench tested on actual hardware: We cycled this cell in a GT-S5830 chassis and confirmed the charge IC accepted the new BMS handshake without error flags. Charge termination cut off cleanly at 4.2V and the protection circuit responded correctly to a simulated short on the discharge path.
- First-cycle fuel gauge recalibration: After fitting this cell, disable fast charging if available and run one full discharge-charge cycle from 100% down to automatic shutdown and back to full. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before resuming normal use.
Sudden shutdown at 20–30% on the GT-S5830 after a cell swap
The GT-S5830's fuel gauge IC retains the discharge curve of the old, degraded cell in its internal register. When the new cell is installed, the IC does not immediately know the new cell's voltage-versus-capacity profile. Under modem or display load, the new cell's voltage can sag briefly — enough to cross the IC's cutoff threshold even though usable capacity remains. The fix is one complete discharge-charge cycle with no fast charging, which forces the coulomb counter to relearn the new curve. After that cycle, shutdowns at 20–30% should stop.
Phone showing wrong battery percentage after replacement
The Galaxy Ace stores fuel gauge calibration data tied to the previous cell's internal resistance and voltage slope. A fresh cell has lower impedance, so the IC overestimates remaining charge at high states and underestimates it near empty — producing jumpy or inaccurate readings. Run the phone down to automatic cutoff, then charge uninterrupted to 100% with the screen off. This single full cycle writes a corrected baseline to the fuel gauge and the percentage display should stabilise from that point forward.