Soundcast VG1Ba Replacement Battery 3.7V 3400mAh

Soundcast VG1 — 3.7V Li-ion Replacement Battery (VG1Ba)

This is a 3.7V 3400mAh Li-ion cell built to fit the Soundcast VG1 portable Bluetooth speaker. It matches the OEM part number VG1Ba and slots into the VG1's battery bay with the original connector. When the stock cell loses its ability to hold a charge, this replaces it and restores cordless playback.

• VG1 platform fit: The VG1Ba cell operates at 3.7V nominal, which matches the VG1's amplifier and Bluetooth radio power rails. The connector pinout and BMS communication are consistent with the OEM cell — the speaker's charge circuit recognises the pack normally.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the VG1 platform and confirmed the BMS accepted charge from the OEM charger without fault flags. Cell voltage at full charge settled at 4.19V, consistent with a healthy Li-ion pack.
• Fuel gauge reset after swap: After fitting this battery, run the VG1 down until it shuts off on its own — do not manually power off. Then charge it uninterrupted to full. This lets the speaker's fuel gauge recalibrate to the new cell's actual capacity and prevents false "low battery" warnings mid-session.

Capacity fade from constant top-off charging on the VG1

The VG1 is often left on a desk or shelf and plugged in whenever it drops below 80%. That pattern — charging before the cell gets a real discharge — causes lithium plating stress on the anode and compresses the cell's usable capacity over time. The speaker's charge indicator still shows "full," but the actual stored charge shrinks with each shallow cycle. To slow this, let the cell discharge below 20% at least once a month before recharging. A fresh 3400mAh cell gives the fuel gauge a clean baseline to work from; pairing it with full discharge cycles keeps that figure accurate.

Audio distorting before the battery indicator reaches empty

When the VG1's Li-ion cell is aged or partially degraded, its internal resistance rises. At loud volume, the amplifier draws a spike of current and the cell voltage sags briefly below the amplifier's stable operating threshold — you hear this as clipping or distortion even though the indicator still shows charge remaining. The BMS hasn't triggered a cutoff yet, so the speaker stays on, but the amp is starved of clean voltage. If this happens on a new battery, check that the charge cycle reached 4.2V before use — an incompletely charged cell will sag earlier under the same load.