About this replacement
Dell Chromebook 13 3380 Series — 7.6V Li-Polymer Replacement Battery (FMXMT / V1P4C)
This is a 7.6V, 7000mAh (53.2Wh) Li-Polymer replacement battery for the Dell Chromebook 13 3380 series. It fits the 3380-6TXJ4, 3380-7TFG4H, and 3380 base model, as well as the Inspiron 7486 Chromebook 14 2-in-1. Direct OEM part number cross-references are FMXMT and V1P4C.
- Chromebook 13 3380 and Inspiron 7486 2-in-1 fit: These models share the same 7.6V battery rail, physical connector pinout, and BMS handshake protocol. The same cell works across the cluster because Dell used a common power board layout across these 13–14 inch Chromebook chassis.
- Bench tested on actual hardware: We ran this cell on the 3380 platform and confirmed the BMS handshake initialised correctly, the BIOS accepted the cell without fault codes, and charge regulation stepped through all three charge stages without tripping the protection circuit.
- BIOS learn cycle after install: After fitting this cell, run one full discharge to the hibernate cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears on first boot after every cell swap.
BIOS reporting poor battery health immediately after replacement
The Dell BIOS reads health data from EEPROM registers embedded in the battery pack. When you swap cells, the BIOS compares the new cell's EEPROM values against the charge history stored in firmware — the mismatch triggers a false health warning. This is not a fault with the replacement cell. Run one full discharge-to-hibernate cycle followed by an uninterrupted charge to 100% and the BIOS recalibrates. After two to three full cycles the health status clears and reports correctly.
Laptop shuts down at 20–30% charge shown on screen
This happens when the fuel gauge IC hasn't calibrated against the new cell yet. The gauge was trained on the old cell's discharge curve, so it misreads the remaining capacity and signals shutdown too early. The cell itself still has usable charge at that point — the voltage simply drops below what the uncalibrated gauge expects under CPU and display load. Run two full discharge-to-hibernate cycles charged back to 100% each time, and the fuel gauge IC relearns the new cell's voltage cliff at the correct threshold.