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Dell Alienware M15 R2 Replacement Battery 11.4V 6050mAh

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From $109.99 USD $135.99
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Fits Dell Alienware M15 R2 and M17 R2 laptops; replaces OEM part numbers 08K84V, Y9M6F, and YM9KC.
11.4V at 6050mAh delivers 68.97Wh — matches the original capacity so the M15 R2 fuel gauge recognizes the full system load without voltage sag.
Connector is a four-pin proprietary Dell socket; slides into the battery bay parallel to the keyboard and locks with a single latch tab on the right side.
We ran a full discharge cycle on an M15 R2 motherboard; the BMS held 11.4V through CPU and GPU draw, then cut cleanly at the firmware threshold without early shutoff.
After installation, discharge fully to sleep mode then charge uninterrupted to 100% — this resets the Dell BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap.
Delivery time

This product ships directly from our Manufacturer's Warehouse and is usually delivered within 7 – 10 business days to your doorstep.

Discount: As a thank you for your patience, enjoy 5% off on your order
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Fresh Battery, Worth the Wait

To provide the highest-quality replacement battery, we ship this battery directly from the manufacturer rather than from aging warehouse inventory. This means delivery may take a little longer, but it helps ensure you receive a fresh battery with better performance, a longer lifespan, and greater reliability.

Estimated delivery: 7–10 business days
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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.

Delivery and Shipping

🔹 Most orders ship the next day, and we use FedEx, UPS, Purolator and other carriers to get them to you. Lithium batteries have to ship by ground only, not air or USPS. Make sure your address is right before you order, because if we have to send it back, you pay for shipping again.

Disclaimer

⚠️ Disclaimer: All product names, trademarks, and registered trademarks belong to their respective owners.

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

Voltage

11.4V

Amp

6050mAh

Dell Alienware M15 R2 — 11.4V Li-Polymer Replacement Battery (08K84V)

This 11.4V, 6050mAh (68.97Wh) lithium-polymer cell replaces the original battery in the Dell Alienware M15 R2 and M17 R2 gaming laptops. It fits the same connector and BMS handshake as OEM part numbers 08K84V, Y9M6F, and YM9KC. Install it when the original cell no longer holds a usable charge under GPU and CPU load.

  • M15 R2 and M17 R2 platform fit: Both the M15 R2 and M17 R2 share the same battery bay geometry, connector pinout, and BMS communication protocol — so one cell covers both chassis without modification.
  • Bench tested on actual hardware: We cycled this cell on an M15 R2 under sustained GPU load. The BMS held the voltage rail stable and passed BIOS battery authentication without triggering an unknown-device warning.
  • First-cycle calibration on Alienware firmware: After installing, run the laptop down to hibernate-cutoff under normal use, then charge uninterrupted to 100%. This single discharge-charge cycle resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on Alienware firmware.

Why the M15 R2 shuts down at 20–30% battery remaining after a cell swap

The Alienware BIOS uses a fuel gauge IC that builds a charge map against the original cell's EEPROM data. A new cell resets that map, so the IC loses track of where the actual voltage cliff sits. Under full CPU and discrete GPU load, current draw spikes sharply, and the new cell's voltage drops faster than the stale map predicts — triggering an emergency shutdown well above 0%. Running two or three full discharge-to-hibernate cycles re-trains the fuel gauge IC against the new cell's actual chemistry and eliminates the premature cutoff.

BIOS reporting wrong Wh rating after replacement cell is installed

The Wh figure shown in BIOS and Dell SupportAssist is read from the cell's EEPROM, not measured live. If the replacement cell's EEPROM carries a rated Wh value that differs from the original OEM figure, the system will display the stored number regardless of actual capacity. This is a data field mismatch — it does not affect charging behaviour or output voltage. To confirm the cell is functioning correctly, check that BIOS shows the battery voltage at or near 11.4V and that charge current is flowing normally.

Compatible Models

Alienware M15 R2 Alienware M17 R2 Alienware M15 ALW15M-D4746W Alienware m17 R2-C7XD9 Alienware M15 ALW15M-D4725B Alienware M15 ALW15M-D4505B Alienware M15 ALW15M-D4736W Alienware M15 R2 ALW15M-R4958W Alienware M15 ALW15M-D4738W Alienware M17 R2 P41E Alienware M15 ALW15M-D4758W Alienware M15 ALW15MD4725W Alienware M15 R2 P87F Alienware M15 ALW15M-D4958W Alienware M15 ALW15M-D4728W

Replaces Part Numbers

08K84V Y9M6F YM9KC

Technical Specifications

Voltage11.4V
Amp Hours6050mAh
Capacity6050mAh
Rate68.97Wh
Net Weight204.8g /7.22 oz
Gross Weight464.8g /16.40 oz
Approximate Weight464.8g /16.40 oz
Dimension 331.50 x 127.20 x 9.30mm

Product Highlights

  • Brand: Dell
  • Manufacturer: CS
  • Series: Standard
  • Color: Black
  • Product Type: Li-Polymer
  • Battery Type: Li-Polymer
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

My Alienware M15 R2 BIOS shows the new battery as "poor health" or "unknown" right after installation — is the cell faulty?

The BIOS reads health status from EEPROM data written to the original cell over its lifetime. A fresh cell has no accumulated cycle data, so the firmware flags it as unknown or degraded until the learn cycle runs. Power the laptop down to hibernate-cutoff under normal load, then charge uninterrupted to 100%. After one complete cycle, the BIOS health status updates to reflect the new cell.

The fuel gauge is jumping around — showing 60%, then 45%, then back to 55% within minutes. What's causing that?

The fuel gauge IC calibrates its charge map against discharge curves from the old cell. With a new cell installed, the stored curves no longer match the actual chemistry, so the reported percentage swings erratically. This settles after two to three full discharge-to-charge cycles as the IC rebuilds its map against the new cell's real voltage profile. Do not rely on the percentage readout until those calibration cycles are complete.

The replacement battery stops charging at 80% and won't go higher — is something wrong with the cell?

This is almost always the Alienware Command Center or Dell Power Manager charge limit, not a cell fault. Dell firmware includes a configurable charge cap — commonly set to 80% — to reduce long-term cell stress during AC-connected use. Open Dell Power Manager, navigate to Battery, and set the charge mode to "Primarily AC" or disable the custom charge stop. The cell will then charge to 100%.

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