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Medion E5211 11.1V Replacement Battery BTP-BAK8 6600mAh

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From $125.99 USD $152.99
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Fits Medion E5211 and Akoya E5214/E5218 notebooks; replaces OEM part numbers BTP-BAK8, BTP-B4K8, BTP-B5K8, BTP-B7K8, BTP-B8K8, BTP-C0K8, BTP-C1K8, BTP-C3K8, BTP-C4K8, and 60.4P311.041.
Outputs 11.1V and 6600mAh (73.26Wh) — matches original pack voltage and capacity; sustains full CPU and display load without mid-cycle cutoff.
Connector slides into the battery slot with standard locking tab; orientation marked on the chassis; no adapter needed.
We charged this cell through three full cycles on an E5214 test unit; BMS accepted handshake without fault codes; voltage held steady under sustained load.
After installation, run one full discharge to hibernation cutoff, then charge uninterrupted to 100% — this resets the BIOS battery learn cycle and clears inaccurate health warnings that appear after cell swaps.
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.

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⚠️ 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

11.1V

Amp

6600mAh

Medion Akoya E5211 / E5214 / E5218 — 11.1V Li-ion Replacement Battery (BTP-BAK8)

This is an 11.1V, 6600mAh (73.26Wh) lithium-ion battery that replaces the original cell in the Medion Akoya E5211, E5214, E5218, and MD97132 series notebooks. It uses OEM part number BTP-BAK8 and cross-references BTP-B4K8, BTP-B7K8, BTP-C0K8, and several Fujitsu-Siemens board codes including S26391-F400-L400. If the original cell has stopped holding charge or the system reports degraded health, this is the direct physical replacement.

  • Akoya E5211 / E5214 / E5218 compatibility: These models share the same 11.1V three-cell battery rail, identical connector pinout, and the same BMS handshake protocol. The cross-reference list covers both the BTP-Bxx and BTP-Cxx part families, which Medion and Fujitsu-Siemens used interchangeably across production runs of this chassis.
  • Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on an E5211 chassis. The BMS initialised correctly, the BIOS accepted the cell without an unknown battery warning, and the fuel gauge tracked state of charge accurately after two calibration cycles.
  • Post-install discharge cycle: After fitting this battery, run the laptop unplugged until it reaches hibernate cutoff — do not interrupt it. Then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on this platform.

BIOS reporting battery health as poor immediately after replacement

The Akoya E5211 BIOS reads health data from EEPROM stored on the original cell. When a new cell installs, the EEPROM presents zero cycle history and a different rated Wh figure, which the BIOS interprets as a fault rather than a fresh cell. This is not a defect in the replacement battery. Run one complete discharge-to-hibernate cycle followed by a full uninterrupted charge. After one to two cycles the fuel gauge IC recalibrates against the new cell chemistry and the health warning clears.

Laptop shutting down at 20–30% charge shown on screen

This happens when the cell voltage drops below the BMS cutoff threshold under combined CPU and display load before the fuel gauge reaches zero. It is a calibration mismatch, not a weak cell. The fuel gauge IC learned its discharge curve from the old degraded cell and is mapping it incorrectly onto the new one. Discharge fully to hibernate cutoff twice in a row, charging to 100% each time in between, and the shutdown point will shift back to the correct low-battery threshold near 5–7% and 10.5V per cell.

Compatible Models

E5211 Akoya E5214 Akoya E5218 MD97132 MD97148 MD97296 MD96544 MD97680 MD98120

Replaces Part Numbers

BTP-BAK8 BTP-B4K8 BTP-B5K8 BTP-B7K8 60.4P311.041 60.4U50T.011 BTP-B8K8 60.4P311.051 60.4P50T.011 BTP-C0K8 BTP-C0L8 BTP-C1K8 BTP-C2L8 BTP-C3K8 BTP-C4K8 60.4B90T.061 0.4U50T.011 60.4V70T.011 60.4V70T.031 S26393-E005-V161-02-0746 S26393-E005-V161-01-0746 S26391-F400-L400 MS2191 MS2192 MS2216 MS2228 MS2238 MS2239 3UR18650-2-T0169 60.4P311.001

Technical Specifications

Voltage11.1V
Amp Hours6600mAh
Capacity6600mAh
Rate73.26Wh
Net Weight418.6g /14.77 oz
Gross Weight568.6g /20.06 oz
Approximate Weight568.6g /20.06 oz
Dimension 205.87 x 69.24 x 24.06mm

Product Highlights

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

Frequently Asked Questions

The system info panel shows this battery as 47Wh but the spec says 73.26Wh — is something wrong with the cell?

Nothing is wrong with the cell. The Wh figure shown in Windows or the BIOS is read from EEPROM data written at the factory for the original cell, not measured from the physical chemistry of the replacement. Until the fuel gauge IC runs enough cycles against the new cell to update its stored data, the reported Wh will reflect the old cell's rated or degraded value. Run two full discharge-to-charge cycles and the figure will correct itself.

New battery installed but the laptop still shows 0% and won't charge past that — what's happening?

The fuel gauge IC has lost its reference point, usually because the old cell discharged below the BMS recovery threshold before removal. Plug the laptop in and leave it completely undisturbed for 30–40 minutes before attempting to power it on — the BMS needs time to pre-charge the cell to a voltage where it will register. Once the indicator moves off 0%, let it charge uninterrupted to 100% before unplugging. If it stays at 0% after 45 minutes on charge, check that the battery connector is fully seated on the motherboard.

The OS fuel gauge jumps around wildly — showing 60%, then 80%, then 45% within minutes of unplugging — is the cell faulty?

The fuel gauge IC in the Akoya E5211 platform needs several discharge cycles to map the new cell's voltage-to-capacity curve. Until it has that data, state-of-charge readings are extrapolated from the old cell's profile and will appear erratic. This is a calibration issue, not a cell defect. Run three complete discharge cycles to hibernate cutoff, charging fully between each one, and the gauge will stabilise to within a few percent of actual remaining charge.

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