About this replacement
JBL Pulse 4 — 3.7V Li-ion Replacement Battery (SUN-INTE-168)
This is a 3.7V, 7800mAh (28.86Wh) Li-ion replacement battery for the JBL Pulse 4 portable Bluetooth speaker. It restores power to the speaker's audio amplifier, Bluetooth radio, and LED light ring. Fit is confirmed against OEM part numbers SUN-INTE-168 and DH03073CHM.
- Pulse 4 compatibility: The Pulse 4 runs a single-cell 3.7V pack that powers both the Class D amplifier and the LED sync circuit from the same voltage rail. This cell matches that rail and the connector pinout used by the Pulse 4's charge management IC.
- Bench tested on actual hardware: We cycled this pack through the Pulse 4's onboard BMS and confirmed the protection circuit trips correctly on overcurrent and that the fuel gauge registers capacity accurately across charge states.
- Discharge cycling for the Pulse 4: The Pulse 4 is typically kept on a desk and topped off constantly. Let the battery drop below 20% at least once a month before recharging — skipping this causes fuel gauge drift and accelerates cell capacity fade.
Why the Pulse 4 LED ring flickers under heavy bass at high volume
The LED ring and amplifier share the same battery rail. At high volume with heavy bass, the amplifier pulls sharp current spikes. If the cell's internal resistance is elevated — common in aged packs — voltage on the shared rail briefly sags. The LED controller reads that sag as a low-power event and dims or flickers the ring. A fresh cell with lower internal resistance holds the rail steady under those spikes.
Pulse 4 not waking from USB-C charge after sitting unused for months
Li-ion cells left fully discharged for extended periods drop below the minimum voltage USB-C PD chargers will accept — typically around 2.5V per cell. The Pulse 4's BMS blocks charge input at that level to protect the cell, so the speaker appears completely dead. Some packs recover with a trickle charge applied directly, but if the cell has sat below 2.5V for weeks, recovery is unlikely. Prevent this by storing the speaker at 40–60% charge if it won't be used for more than a few weeks.