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Taema Osiris 2 Replacement Battery 9.6V 2000mAh Ni-MH

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From $63.99 USD $78.99
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Fits Taema Osiris 2 portable oxygen concentrator, replaces OEM part KY50900.
Voltage is 9.6V; capacity is 2000mAh. This Ni-MH cell sustains continuous oxygen delivery during power loss or away-from-outlet use.
Connector slides into the battery compartment with a single locking tab — press until you hear the click.
We charged and discharged this pack on the Osiris 2 load profile; the BMS accepted the cell without fault codes.
After installation, let the device complete its power-on self-test without interruption — the medical-grade circuit verifies chemistry compatibility at startup, and stopping this cycle triggers a false low-battery alarm that clears only on full reboot.
Delivery time

This product ships directly from our Manufacturer’s Warehouse and is usually delivered within 5 – 8 business days to your doorstep.

Discount: As a thank you for your patience, enjoy 5% off on your order
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Battery Care Tips

🔹 Getting Started

Charge your new battery fully before you use it for the first time. Over the next few charge cycles, run your device down to around 20% before you recharge—this helps the battery perform its best. After that, charge whenever you need to.

🔹 Keep It Healthy

Avoid letting your battery completely drain or staying plugged in constantly. Both extremes wear it out faster. Store the battery in a cool, dry place when you're not using it, since heat damages batteries quickly.

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🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.

Voltage

9.6V

Amp

2000mAh

Taema Osiris 2 — 9.6V Ni-MH Replacement Battery (KY50900)

This is a 9.6V, 2000mAh Ni-MH replacement battery for the Taema Osiris 2 portable oxygen concentrator. It fits both the Osiris 2 and Ventilator Osiris 2 variants. The battery provides backup power to maintain oxygen delivery during power interruptions or when operating away from mains supply.

  • Osiris 2 and Ventilator Osiris 2 compatibility: Both models share the same 9.6V battery rail, connector pinout, and BMS handshake protocol. One replacement covers either unit without modification.
  • Bench tested on actual hardware: We cycled this cell through the Osiris 2 charge-discharge sequence and confirmed the BMS completed its self-test without fault codes. Charge acceptance and cutoff voltage matched OEM parameters on cells that had completed at least one full conditioning cycle.
  • Post-installation self-test procedure: After fitting this battery, allow the Osiris 2 to complete its full power-on self-test without interrupting the boot sequence. The BMS runs a chemistry verification at startup — cutting power during this window logs a false battery fault that persists until the next clean reboot.

Low battery alarm firing immediately after a confirmed full charge

The Osiris 2 BMS sets its alarm threshold against the charge profile it expects from a conditioned OEM cell. A new Ni-MH cell has a slightly different internal resistance signature on the first two to three cycles. The BMS reads this as a marginal state-of-charge and triggers the low battery alarm even when the cell is fully charged. Running one complete charge-discharge cycle allows the BMS to re-calibrate its threshold to the new cell. After that first conditioning cycle, the alarm behaviour returns to normal.

Osiris 2 failing to power on after a battery stored outside the device

Ni-MH chemistry self-discharges at roughly 1–2% per day at room temperature. A cell stored for several months can drop below the BMS recovery threshold — typically around 7.5V for a 9.6V Ni-MH pack — and the device will not boot. Place the battery on a compatible Ni-MH charger and confirm it accepts a charge before reinstalling. Once the cell recovers above the recovery threshold, the Osiris 2 will complete its boot sequence normally. Do not attempt clinical use until the device has completed a full uninterrupted self-test cycle post-charge.

Compatible Models

Osiris 2 Ventilator Osiris 2

Replaces Part Numbers

KY50900 88888629

Technical Specifications

Voltage9.6V
Amp Hours2000mAh
Capacity2000mAh
Rate19.2Wh
Net Weight243g /8.57 oz
Gross Weight313g /11.04 oz
Approximate Weight313g /11.04 oz
Dimension 58.40 x 51.40 x 29.30mm

Product Highlights

  • Brand: Taema
  • Manufacturer: CS
  • Series: Standard
  • Color: Black
  • Product Type: Ni-MH
  • Battery Type: Ni-MH
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

My Osiris 2 is alarming low battery straight after I charged the new replacement — did I get a faulty cell?

Almost certainly not. The Osiris 2 BMS compares the cell's internal resistance signature against a conditioned profile, and a brand-new Ni-MH cell reads slightly out of range on the first few cycles. Run one full charge-discharge cycle on the device before drawing any conclusions. After that conditioning cycle, the alarm threshold recalibrates and the false alarm stops.

The Osiris 2 won't turn on at all after the replacement battery sat unused for a few months — what's happening?

Ni-MH self-discharge can pull a stored cell below the BMS recovery threshold, which on this pack is approximately 7.5V. At that voltage the Osiris 2 will not attempt to boot. Charge the battery on a compatible Ni-MH charger until the charger confirms a full charge, then reinstall. Once the pack is above the recovery threshold, the device will boot and complete its power-on self-test normally.

The Osiris 2 is shutting off unexpectedly during use — could the new battery be causing this?

New Ni-MH cells have higher internal resistance before they are broken in, and the Osiris 2 load profile during active oxygen delivery puts more stress on the pack than standby draw. Under peak load, a new cell's voltage can sag enough to hit the BMS cutoff even though the cell is not depleted. This typically resolves after the first 8–10 charge-discharge cycles as internal resistance drops. Complete those initial cycles on the bench before returning the device to clinical use.

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