About this replacement
JBL Flip Essential 2 — 3.7V Li-ion Replacement Battery (ICA085NA)
This is a 3.7V, 3350mAh Li-ion replacement battery for the JBL Flip Essential 2 Bluetooth speaker (JBLFLIPES2). It replaces the original ICA085NA cell when the speaker stops holding a charge or shuts off unexpectedly during playback. Capacity figures are taken from product data — 12.4Wh total.
- Flip Essential 2 cell fit: The Flip Essential 2 and its JBLFLIPES2 variant share the same 71 × 20 × 20mm cell bay, 3.7V nominal rail, and BMS connector pinout. Swapping to a mismatched voltage or footprint will prevent the fuel gauge from initialising correctly.
- Bench tested on actual hardware: We cycled this cell through the JBL charging circuit and confirmed the BMS handshake completes without error flags. Charge termination triggers cleanly at full capacity with no overcharge bleed.
- Fuel gauge reset after install: After fitting this battery, run the speaker down past the first low-battery warning before recharging — do not top it off immediately. Skipping this step causes the fuel gauge to misread state-of-charge from the first cycle, showing full when the cell is at roughly 70%.
Capacity fade from constant desk-top charging on the Flip Essential 2
The Flip Essential 2 sees a lot of top-off charging — plugged in at a desk, recharged after every short session before the cell drops below 50%. Li-ion cells stressed between 80–100% repeatedly lose capacity faster than cells that regularly cycle through a fuller range. Discharge the speaker to below 20% at least once a month before plugging in. This keeps the electrochemical bookkeeping accurate and slows the voltage-plateau compression that makes the fuel gauge report full charge on a degraded cell.
Audio distorting before the battery indicator reaches empty
The amplifier in the Flip Essential 2 pulls a short high-current spike at peak volume, and a worn or deeply cycled cell sags in voltage under that load before the fuel gauge triggers a low-battery warning. The result is audible clipping at mid-to-high volume while the indicator still shows charge remaining. A fresh cell at 3.7V nominal holds the rail stable under the amp spike. If distortion disappears after installing this replacement, the original cell's internal resistance had risen enough to cause voltage sag — confirm by checking that the low-battery LED now aligns with actual audio cutoff rather than appearing after distortion starts.