TDK Life on Record A73 Replacement Battery 7.2V 2000mAh

TDK Life on Record A73 — 7.2V Ni-MH Replacement Battery (6AA-HHC)

This is a 7.2V, 2000mAh Ni-MH replacement battery for the TDK Life on Record A73 and A73 Boombox portable speakers. It replaces OEM part number 6AA-HHC and restores wireless operation when the original cell no longer holds a useful charge. Capacity is 14.4Wh, matching the original pack.

• A73 and A73 Boombox compatibility: Both models share the same battery bay geometry, voltage rail, and connector pinout. The 7.2V Ni-MH chemistry is what the speaker's charging circuit expects — swapping chemistry here causes incorrect charge termination and shortens cell life.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the A73 platform. The protection circuit terminated charge correctly at full capacity, and voltage held stable under sustained audio output without dropping into low-battery cutoff prematurely.
• Ni-MH memory management for daily use: Unlike Li-ion, Ni-MH cells in this speaker benefit from a full discharge-to-empty cycle every four to six weeks. Constant partial top-off charging causes voltage depression — the speaker reports full but actual usable capacity drops noticeably over time.

Audio distortion before the battery indicator reaches empty on the A73

Ni-MH cells exhibit a steeper voltage drop curve near end-of-discharge than the A73's fuel gauge is calibrated to track precisely. As the pack approaches depletion, output voltage sags under the amplifier's current draw before the indicator registers low. The amplifier clips at reduced rail voltage, producing audible distortion — crackling or thinning of bass — while the display still shows one or two bars. If this starts happening earlier than expected, run the pack through a full discharge cycle to around 6.0V total pack voltage before recharging.

A73 Bluetooth dropping out at high volume on a freshly charged battery

At peak volume, the A73 amplifier and Bluetooth radio draw current simultaneously — the combined spike can cause instantaneous voltage sag on a weakened or newly installed cell. A new Ni-MH pack sometimes needs two to three full charge-discharge cycles before the cells reach rated capacity and internal resistance stabilises. Until that break-in is complete, the radio module can brown out briefly under high combined load and drop the Bluetooth connection. Run two full cycles before testing at maximum volume.