Dell Latitude E6400 11.1V Replacement Battery PT434 6600mAh
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Dell Latitude E6400 11.1V Replacement Battery PT434 6600mAh - 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
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🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.
Dell Latitude E6400 11.1V Replacement Battery PT434 6600mAh - is backordered and will ship as soon as it is back in stock.
Voltage
11.1V
Amp
6600mAh
Dell Latitude E6400 / E6500 — 11.1V Li-ion Replacement Battery (PT434)
This is an 11.1V, 6600mAh (73.26Wh) Li-ion battery for the Dell Latitude E6400, E6500, Precision M2400, and Precision M4400 series laptops. It replaces a wide range of OEM part numbers including PT434, KY477, FU268, C719R, and TX283. Install it when the original cell can no longer hold charge through a standard work session unplugged from mains.
- E6400 / E6500 / M2400 / M4400 compatibility: These four platforms share the same 11.1V battery bay, connector pinout, and SMBus communication protocol — one cell fits all without modification or adapter.
- Bench tested on actual hardware: We ran this cell on an E6400 through full charge and discharge cycles. The BMS held communication across the SMBus, charge termination triggered cleanly at 100%, and the pack reported correct voltage at each state-of-charge step.
- First-cycle calibration after install: After fitting this battery, let the laptop discharge fully to hibernate cutoff, 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 Dell Latitude hardware.
BIOS reporting battery health as poor immediately after installation
Dell's BIOS reads health data from the EEPROM embedded in the battery pack, not from live cell measurements. A new replacement cell carries EEPROM values that don't yet match the laptop's learned charge history, so the BIOS flags it as degraded on first boot. Running one complete discharge-to-hibernate then a full uninterrupted charge gives the firmware enough data to recalibrate. After two to three full cycles, the health indicator typically returns to normal without any firmware update or BIOS change.
Laptop shutting down at 20–30% charge shown on screen
This happens when the fuel gauge IC still holds calibration data from the old, degraded cell. The percentage shown is calculated against the old cell's curve, so the new cell hits its actual voltage floor well before the gauge reads zero. The fix is a full discharge to hibernate cutoff — not a forced shutdown — followed by a complete charge to 100%. After two to three of these cycles the fuel gauge IC recalibrates against the new cell's actual capacity curve and shutdowns stop occurring above 10%.
Compatible Models
Replaces Part Numbers
Technical Specifications
Product Highlights
- Brand: Dell
- Manufacturer: CS
- Series: Standard
- Color: Silver Grey
- Product Type: Li-ion
- Battery Type: Li-ion
- Warranty: 12 Months
- Bulk Orders: sales@batteryweb.com
Frequently Asked Questions
My Dell Latitude E6400 shows "plugged in, not charging" after fitting this battery — what's causing it?
This is almost always a BIOS charge-limit flag left over from the previous battery's end-of-life state. Go to Dell's BIOS (F2 at boot), navigate to Power Management, and check whether a primary battery charge threshold is set. If the threshold is set to 80%, the laptop stops charging there by design — raise it to 100% or disable the limit entirely, then reconnect the charger.
The Wh rating shown in Windows Battery Report doesn't match the 73.26Wh spec — is the cell wrong?
No — this is an EEPROM reporting difference, not a capacity fault. The battery's embedded EEPROM stores a rated Wh figure from the cell manufacturer's specification, which can differ slightly from the actual measured capacity of the chemistry we source. Windows reads the EEPROM value directly. Run two full discharge-to-hibernate and charge-to-100% cycles; the fuel gauge IC then reports against measured capacity and the Windows figure will align more closely with the listed 73.26Wh.
The battery percentage jumps erratically — drops 15% in minutes then sits at one level for a long time. How do I fix this?
The fuel gauge IC on the E6400's system board calibrates against the previous cell's charge curve. With a new cell installed, the IC's reference table is mismatched, causing the gauge to skip and stall at certain percentages. Discharge the laptop fully to the point where it hibernates automatically, then charge uninterrupted to 100% without using the laptop. Repeat this cycle three times. By the third cycle the gauge IC relearns the new cell's voltage-to-capacity curve and percentage readings stabilise.
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