Samsung SCH-i415 Replacement Battery EB-L1K6ILZ 3.7V 3600mAh

Samsung SCH-i415 / Galaxy S Relay 4G — 3.7V Li-ion Replacement Battery (EB-L1K6ILZ)

This is a 3.7V Li-ion replacement battery rated at 3600mAh (13.32Wh) for the Samsung SCH-i415 Stratosphere II and Galaxy S Relay 4G. It replaces OEM part EB-L1K6ILZ. These are CDMA-era Samsung smartphones that share the same battery bay dimensions and connector pinout across the SCH-i415 platform.

• SCH-i415 / Stratosphere II / Galaxy S Relay 4G platform fit: These models share the same battery form factor, voltage rail, and BMS communication protocol. The EB-L1K6ILZ connector carries both power and fuel-gauge data lines, so the replacement cell must match the original footprint exactly — and this one does at 69.70 × 51.90 × 10.90mm.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the SCH-i415 platform. The BMS accepted charge handshake without rejection errors, and the protection circuit tripped correctly at low-voltage cutoff. No thermal anomalies were recorded during the charge cycle.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one full discharge-to-charge cycle. The fuel gauge IC on these Samsung models is calibrated to the original cell's discharge curve. Skipping this step often causes erratic percentage readings on a new cell before the coulomb counter has re-anchored its reference points.

Sudden shutdown at 20–30% on the SCH-i415 after cell replacement

This is a voltage cliff problem, not a capacity problem. When the SCH-i415's modem fires during a call or the screen ramps brightness, the instantaneous current draw pulls cell voltage below the BMS protection threshold — triggering a hard cutoff even though the fuel gauge still shows charge remaining. A new cell with a mismatched internal resistance curve makes this worse in the first few cycles. Running two full discharge-charge cycles without fast charging allows the internal resistance to stabilise and the fuel gauge IC to map the actual voltage curve of the new cell.

SCH-i415 not powering on after the battery sat in storage

Li-ion cells that drop below approximately 2.5V per cell trigger a BMS lockout to prevent unsafe charging of a deeply discharged cell. The SCH-i415 will show no boot screen and no charge indicator — appearing completely dead. Connect the phone to a wall charger rated at 5V and leave it untouched for 20–30 minutes. The charge IC will trickle current into the cell at a safe low rate until voltage recovers above the BMS re-enable threshold, after which normal charging resumes. Do not attempt to force-boot during this window.