MSI MegaBook S271 Replacement Battery 14.4V 4400mAh 0299-MP1006J443
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MSI MegaBook S271 Replacement Battery 14.4V 4400mAh 0299-MP1006J443 - is backordered and will ship as soon as it is back in stock.
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Battery Care Tips
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
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
⚠️ 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.
MSI MegaBook S271 Replacement Battery 14.4V 4400mAh 0299-MP1006J443 - is backordered and will ship as soon as it is back in stock.
Voltage
14.4V
Amp
4400mAh
MSI MegaBook S271 — 14.4V Li-ion Replacement Battery (BTY-S27)
This is a 14.4V, 4400mAh (63.36Wh) Li-ion battery pack for the MSI MegaBook S270, S271, S262, and S260 series notebooks. It replaces OEM part numbers including BTY-S25, BTY-S27, BTY-S28, and 0299-MP1006J443, among others. If your original cell no longer holds charge through a normal session, this swap restores full capacity to the same voltage rail the laptop expects.
- MegaBook S260–S271 series fit: These models share the same connector pinout, 14.4V rail, and BMS handshake protocol across the S260, S262, S270, and S271 variants. The cell communicates charge state to the EC via the same SMBus lines, so the pack seats and registers without modification.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the MegaBook platform and confirmed the BMS engaged charge termination correctly at full capacity, with no overcharge events or premature cutoff under sustained CPU and display load.
- Post-install calibration on MSI notebooks: After fitting this cell, run the laptop down until it hibernates on its own, then charge uninterrupted to 100% without waking it. This forces the BIOS battery learn cycle to reset against the new cell's actual capacity and clears the false "battery health poor" flag that appears after every cell swap.
BIOS reporting battery health as poor after fitting a new cell
MSI MegaBook firmware stores learned capacity data from the previous cell in the EC's EEPROM. When a new cell goes in, the BIOS compares live readings against stale data and flags a health warning immediately. This is not a fault with the replacement pack — it is a calibration mismatch. Run one full discharge to hibernate cutoff, then charge without interruption to 100%. After that cycle, the BIOS re-learns the cell and the health warning clears.
Laptop shutting down at 20–30% charge shown on screen
This happens when the fuel gauge IC has not yet calibrated against the new cell's discharge curve. The gauge reads a state-of-charge percentage that does not match the actual cell voltage — when the real cell voltage drops below the EC's cutoff threshold, the system shuts down even though the OS shows charge remaining. It is not a fault in the replacement pack. Complete two to three full discharge-to-hibernate and full-charge cycles, and the fuel gauge IC will map the new cell's curve accurately. After calibration, shutdown should not occur above 5% displayed charge.
Compatible Models
Replaces Part Numbers
Technical Specifications
Product Highlights
- Brand: MSI
- Manufacturer: CS
- Series: Standard
- Color: Pearl
- Product Type: Li-ion
- Battery Type: Li-ion
- Warranty: 12 Months
- Bulk Orders: sales@batteryweb.com
Frequently Asked Questions
MSI MegaBook shows the new battery as 0% or "unknown" in Windows — won't charge at all
The EC is reading EEPROM data from the old cell and hasn't initialised the new pack yet. Shut the laptop down fully, remove the AC adapter for 30 seconds, then reconnect power before booting. This forces the EC to re-poll the battery on cold start. If Windows still shows 0%, boot into the BIOS once, let it sit on the battery info screen for 60 seconds, then exit — the EC completes its SMBus handshake there before the OS loads.
The Wh rating showing in Windows (or HWiNFO) doesn't match the 63.36Wh spec — is the pack faulty?
It is not faulty. The Wh figure Windows reports is pulled from the EEPROM embedded in the cell, and third-party replacement packs sometimes carry a rated chemistry value that differs slightly from the actual measured capacity at the fuel gauge IC. The cell chemistry and voltage are correct at 14.4V Li-ion. Confirm the pack is charging by checking the charge current in HWiNFO — if current is flowing and voltage climbs toward 16.8V at full charge, the pack is working correctly regardless of what the Wh field displays.
New MSI MegaBook battery stops charging at 80% and won't go higher
MSI firmware on several MegaBook-era BIOSes includes a charge limit that caps charging at 80% when a battery conservation or eco-charging mode is active. Check the MSI EC or any pre-installed MSI software under Windows — look for a "Battery Calibration" or "Battery Conservation" toggle and switch it off. If no MSI software is installed, enter the BIOS and check for a charge threshold setting under the Power menu. Disable it, save, and reboot — the pack will then charge to 100%.
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