EB504465VU Samsung SGH-T839 Replacement Battery 3.7V 1700mAh

T-Mobile SGH-T839 — 3.7V Li-ion Replacement Battery (EB504465VU)

This is a 3.7V, 1700mAh Li-ion cell for the Samsung SGH-T839 on T-Mobile. It replaces OEM part numbers EB504465VU, EB504465VK, EB504465VA, and EB504465VUBSTD. Swap it in when the original cell no longer holds a usable charge or the phone shuts down unexpectedly under load.

• SGH-T839 fitment: The T839 uses a specific connector pinout and BMS handshake tied to the EB504465 cell family. This replacement matches the physical footprint at 64.60 × 43.90 × 5.20mm and carries the correct identification data the phone's charge IC expects.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the T839 platform, monitoring BMS communication at each stage. The protection circuit engaged correctly at low-voltage cutoff and the charge IC accepted the cell without fault flags.
• Fuel gauge recalibration on first use: After installing a new cell, disable fast charging for one full discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes into an uncalibrated state — preventing erratic percentage readings from the first session.

Sudden shutdown at 20–30% on the SGH-T839 after a cell swap

The T839's modem and display draw spike current that can pull cell voltage below the BMS cutoff threshold faster than the fuel gauge tracks. When the gauge IC is still calibrated to the old cell's discharge curve, it reports 20–30% remaining while actual cell voltage is already near 3.4V under load. The BMS then trips and the phone cuts out — not a faulty battery, but a calibration mismatch. Run one full discharge to auto-off followed by an uninterrupted charge to 100% to reset the coulomb counter.

Phone not powering on after the replacement cell sat in storage

Li-ion cells self-discharge during storage, and if the cell drops below approximately 2.5V per cell the BMS enters lockout mode to prevent damage. The phone will show no response — no charge indicator, no boot. Connect the phone to a wall charger and leave it for 15–20 minutes without pressing the power button; the charge IC needs that window to trickle current into the cell and bring it above the BMS re-enable threshold. Once voltage recovers above 3.0V, normal charging and boot will resume.