Jabra Speak 510 Replacement Battery 3.7V 320mAh

Jabra Speak 510 — 3.7V Li-Polymer Replacement Battery (AHB582035PR-03)

This 3.7V, 320mAh Li-Polymer cell replaces the original AHB582035PR-03 battery in the Jabra Speak 510 portable Bluetooth conference speaker. It fits the compact Speak 510 unit used for wireless speakerphone calls and audio playback. Dimensions are 37.20 × 20.30 × 5.74mm — verify against your existing cell before installation.

• Speak 510 fit notes: The Speak 510 uses a single small Li-Polymer pouch cell on a 3.7V rail. The BMS inside the speaker manages charge termination and low-voltage cutoff — the replacement cell must match the original footprint exactly or the housing will not close flush.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a Speak 510 unit. The onboard BMS accepted the cell without fault flags, balanced charge terminated cleanly at 4.2V, and low-voltage cutoff triggered correctly before cell damage threshold.
• Fuel gauge recalibration after swap: After fitting a new cell, run the Speak 510 down to automatic shutoff once, then charge uninterrupted to full. The speaker's fuel gauge reads the original cell's wear curve — one full discharge-to-charge cycle resets it to the new cell's actual capacity.

Capacity fade from constant desk-top charging on the Speak 510

The Speak 510 sits plugged in between meetings on most desks, which means the 320mAh pouch cell spends hours held at 4.2V. Li-Polymer cells degrade faster when held at full charge under heat — the amplifier and charging circuit both add warmth inside the sealed housing. Over several months this compresses the cell's usable voltage window, so the speaker shuts off earlier than expected even though the indicator showed full. Discharge the cell below 20% at least once a month before recharging to slow this effect.

Audio distorting before the battery indicator reaches empty

At higher volume levels the Speak 510's amplifier draws current spikes the aging 320mAh cell cannot sustain without voltage sag. Internal resistance rises as a Li-Polymer cell ages, so the cell voltage drops sharply under load even when the resting voltage reads mid-range. The BMS reads this sag as a near-empty cell and throttles power — the amplifier clips, producing audible distortion before the indicator hits the low-battery warning. Replacing the cell removes the high internal resistance causing the sag, and distortion at volume should stop immediately.