Olympus BR-402 Replacement Battery 2.4V 800mAh

Olympus DS-5000 / DS-2300 Series — 2.4V Ni-MH Replacement Battery (BR-402 / BR-403)

This is a 2.4V 800mAh Ni-MH battery replacing OEM part numbers BR-402 and BR-403. It fits the Olympus DS-5000ID, DS-5000, DS-2300, and DS-3300 digital dictation recorders. These are handheld audio recorders used for professional transcription and voice memo capture — not cameras.

• DS-5000 / DS-2300 / DS-3300 platform fit: These models share a common 2.4V two-cell Ni-MH battery bay and the same physical form factor — 46.10 × 21.00 × 11.00mm. The connector and contact orientation are identical across the series, so one cell covers the full range.
• Bench tested on actual hardware: We cycled this cell through record and playback loads on a DS-5000. The BMS accepted the cell without prompting a fault or low-battery cutoff at normal operating voltage. Charge termination via delta-V detection behaved correctly in the OEM charger.
• Ni-MH conditioning on dictation recorders: Olympus DS-series recorders are often left in a dock charger between uses. Continuous trickle charging degrades Ni-MH cells faster than it would Li-ion. Rotate full charge-discharge cycles every three to four weeks to slow capacity fade in the new cell.

Why the DS-5000ID shows a low-battery alert immediately after fitting a new cell

Ni-MH cells ship in a partial or depleted state. The DS-5000ID reads terminal voltage to estimate charge level — a new, uncharged cell sits below the device's threshold and triggers the alert on first boot. This is not a fault with the replacement cell. Place the battery in the OEM cradle charger or the device itself for a full charge cycle before use. After one complete charge, the voltage-based indicator should read correctly.

DS-5000 powering off mid-recording with no low-battery warning

This typically happens when the cell has developed high internal resistance — either from age, memory effect, or extended trickle-charge storage. Under record-mode load, voltage sags sharply across that internal resistance and drops below the device's cutoff threshold before the indicator registers low. The fix is a full discharge-then-charge cycle to recondition the cell. If the behaviour persists after two conditioning cycles, measure resting terminal voltage — a healthy 2.4V Ni-MH cell should read at least 2.55V fully charged at rest.