About this replacement
Dell Latitude LST C400ST / L400 / Ls — 14.8V Li-ion Replacement Battery (09H348)
This is a 14.8V, 1900mAh (28.12Wh) Li-ion replacement battery for the Dell Latitude LST C400ST, Latitude L400, and Latitude Ls series notebooks. It cross-references OEM part numbers including 09H348, 312-0025, 451-10064, and 3J426, among others. If your original pack no longer holds charge or the BIOS flags a battery fault, this is a direct cell swap.
- Latitude C400ST and L400 compatibility: These slim Latitude models share the same 14.8V battery rail, connector pinout, and BMS handshake protocol — which is why a single replacement pack covers the full LST, L400, and Ls lineup without modification.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on Latitude hardware. The BMS communicated correctly with the system controller, and the pack reached rated capacity without triggering thermal or voltage cutoff faults.
- Post-install discharge cycle on Dell Latitude: After fitting this battery, run one full discharge 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 these systems.
BIOS reporting poor battery health immediately after swapping the C400ST cell
Dell's BIOS reads health data stored in the old pack's EEPROM and compares it against the new cell on first boot. A fresh cell has no charge history logged, so the system flags it as degraded or unknown — this is a firmware interpretation issue, not a fault with the replacement pack. Running the battery learn cycle (full discharge to hibernate, uninterrupted charge to 100%) writes fresh calibration data to the EEPROM and clears the warning. After one or two full cycles, the BIOS health indicator should display accurately.
Laptop shuts down abruptly at 20–30% charge shown on the gauge
This happens when the fuel gauge IC is still calibrated to the old, degraded cell's discharge curve. Under combined CPU and display load, voltage drops faster than the uncalibrated gauge expects — the system hits its low-voltage cutoff while the display still shows 20–30% remaining. It is not a fault in the new cell. Run two full discharge-to-hibernate and charge-to-100% cycles to re-anchor the fuel gauge IC against the new cell's actual voltage curve, and the shutdowns will stop.