Sanyo SCP-4700 Replacement Battery 3.7V 1700mAh Li-ion

Sanyo SCP-4700 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 1700mAh Li-ion cell built to replace the original battery in the Sanyo SCP-4700 flip phone. It fits directly into the SCP-4700 battery bay and connects to the same three-contact terminal used by the factory cell. Capacity comes from the product specification — 1700mAh, 6.29Wh.

• SCP-4700 fit: The SCP-4700 uses a single-cell 3.7V nominal Li-ion pack with a three-pin connector carrying positive, negative, and a thermistor line for charge temperature monitoring. This cell matches that pin layout and voltage rail.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a SCP-4700 unit. The BMS accepted charge from the OEM charger without fault flags, and the protection circuit tripped correctly at low-voltage cutoff.
• Fuel gauge recalibration on first use: On the first complete cycle after installing this cell, let the battery drain to automatic shutdown before charging back to full. The SCP-4700 fuel gauge IC needs one full reference cycle against the new cell's discharge curve — skip this and percentage readings will drift.

Sudden shutdown at 20–30% on the SCP-4700 after cell replacement

A new Li-ion cell has a slightly different voltage-versus-capacity curve than the aged cell it replaces. The SCP-4700's fuel gauge IC was last calibrated against the old, degraded cell. When the new cell hits a steep voltage drop near 3.5–3.6V under load — typically during a call or screen-on state — the phone interprets it as a hard cutoff and shuts down, even though the display shows 20–30% remaining. One complete discharge-to-shutdown followed by a full charge resets the coulomb counter reference and eliminates the premature cutoff.

SCP-4700 not powering on after the replacement battery sat in storage

Li-ion cells self-discharge during storage. If this replacement cell was stored for an extended period before installation, its resting voltage may have dropped below 2.5V — the threshold at which the BMS latches into lockout to prevent cell damage. The phone will show no response to the power button and may not respond to the charger initially. Connect the OEM charger and leave it for 15–20 minutes without pressing any buttons; the charge IC will trickle current into the cell until the BMS unlocks at approximately 2.9V, after which normal charging resumes.