Vodafone BTR5600B Compatible Battery 3.7V 2200mAh

Vodafone VDA music / v1240 / VDA II — 3.7V Li-ion Replacement Battery (BTR5600B)

This is a 3.7V, 2200mAh Li-ion replacement battery for the Vodafone VDA music, VDA, VDA II, and v1240 mobile phones. It replaces OEM part numbers BTR5600B, ST26A, and ST26B. Swap it in when the original cell no longer holds a charge or the phone shuts down unexpectedly under load.

• VDA music, VDA II, and v1240 compatibility: These models share the same battery bay dimensions, connector pinout, and 3.7V nominal voltage rail. A single cell covers all four fit models without modification.
• Bench tested on actual hardware: We ran this cell through full charge-discharge cycles on the VDA platform. The BMS held voltage within spec across the discharge curve and triggered protection cutoff cleanly at the low-voltage threshold — no false trips under screen and modem load.
• Fuel gauge recalibration on first cycle: On first use after installation, disable any fast-charging accessory and run one complete discharge-charge cycle at standard rate. The phone's fuel gauge IC is calibrated to the old cell's discharge curve. One full cycle at low current lets it re-map against the new cell before fast charging applies higher current to an uncalibrated state.

Sudden shutdown at 20–30% on the Vodafone VDA after a cell swap

This happens because the phone's fuel gauge IC still holds the discharge model of the old, degraded cell. When the new cell's actual voltage drops under modem or display load, the gauge misreads remaining capacity and the phone hits its low-voltage cutoff before the percentage reaches zero. The fix is one full discharge-charge cycle with no fast charging — let the coulomb counter track the new cell's actual curve from top to bottom. After that cycle, shutdowns at 20–30% should stop. If they continue, confirm the battery voltage at shutdown is above 3.4V using a USB voltage logger or the phone's diagnostics menu.

Phone reporting wrong battery percentage after fitting the replacement cell

The fuel gauge IC stores a charge model built from hundreds of cycles on the old cell. A new cell has a different internal resistance and a steeper voltage curve at low charge, so the IC misjudges state-of-charge from the first top-up. This causes the percentage to jump or stall at values like 99% or drop suddenly from 50% to 15%. Drain the battery fully until the phone powers off, then charge uninterrupted to 100% without removing the cable. That single full cycle resets the coulomb counter reference points and brings the displayed percentage back in line with actual cell state.