KAZAM Thunder 345L Replacement Battery 3.8V 1800mAh

KAZAM Thunder 345L — 3.8V Li-ion Replacement Battery (TH345L)

This is a 3.8V, 1800mAh Li-ion replacement battery for the KAZAM Thunder 345L and Thunder 345 LTE smartphones. It replaces OEM part numbers TH345L and TH345L-XDFBK0002256. Swap it in when the original cell has degraded to the point where the phone can no longer hold a usable charge.

• Thunder 345L and 345 LTE compatibility: Both models share the same battery bay dimensions and connector pinout, running the same 3.8V nominal voltage rail with an identical BMS handshake — one cell covers both variants.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the Thunder 345L. The BMS accepted the charge IC handshake correctly, and protection circuits triggered at expected low-voltage cutoff thresholds without false trips.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging starts pushing current into an uncalibrated state — skipping this step causes erratic percentage readings early on.

Sudden shutdown at 20–30% on the Thunder 345L after a cell swap

The Thunder 345L's fuel gauge IC retains the discharge curve of the old, degraded cell. When a fresh cell is installed, the IC misreads the actual remaining charge and triggers a low-voltage shutdown well before the cell is genuinely depleted. The modem and display together pull enough current to cause the cell voltage to sag sharply at that point, which the phone interprets as a dead battery. One full discharge-to-charge cycle with fast charging off forces the coulomb counter to reset against the new cell's actual curve — after that, shutdowns at 20–30% stop.

Phone won't power on after the replacement battery sat in storage

Li-ion cells discharge slowly in storage, and if the cell dropped below approximately 2.5V per cell, the BMS will have entered a lockout state to prevent damage. Plugging the phone in may show no response at all — no charging indicator, no boot. Connect the phone to a wall adapter rather than a PC USB port, which supplies a full 5V at higher current, and leave it for 15–20 minutes without pressing the power button. The charge IC will trickle current into the cell until it clears the BMS lockout threshold and resumes normal charging.