ZTE Blade L5 Plus Li3821T43P3h745741 Replacement Battery 3.8V 2150mAh

ZTE Blade L5 Plus — 3.8V Li-ion Replacement Battery (Li3821T43P3h745741)

This is a 3.8V, 2150mAh Li-ion replacement battery for the ZTE Blade L5 Plus and Blade L5 Plus Dual SIM. It also fits the C370 and Blade L5 variants sharing the same internal cell footprint and connector. OEM part number is Li3821T43P3h745741.

• Blade L5 / C370 platform fitment: The Blade L5, Blade L5 Plus, Blade L5 Plus Dual SIM, and C370 share the same 74.50 x 57.00 x 4.20mm cell cavity, 3.8V nominal rail, and three-contact battery connector — so the same cell works across all four variants without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Blade L5 Plus unit. The BMS handshake completed on first connect, charge IC accepted the cell without rejection flags, and the protection circuit tripped correctly at low-voltage threshold during drain testing.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and run one full discharge-charge cycle before resuming normal use. The phone's fuel gauge IC is calibrated to the old cell's discharge curve — one uninterrupted cycle lets the coulomb counter reset against the new cell and report accurate percentages.

Sudden shutdown at 20–30% on the Blade L5 Plus after a cell swap

This is a voltage cliff issue, not a capacity fault. When the modem transmits or the screen brightness peaks, the phone draws a short burst of high current. If the fuel gauge IC hasn't mapped the new cell's discharge curve yet, it can't predict when terminal voltage will drop below the 3.4V cutoff under that load. The phone shuts down before the reported percentage reaches zero. One full discharge-charge cycle with fast charging disabled resolves this — the coulomb counter rebuilds its model against the actual cell, and the OS percentage tracking stabilises.

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

Li-ion cells self-discharge over time, and if the cell voltage drops below approximately 2.5V, the BMS enters a lockout state to prevent unsafe charging of a deeply discharged cell. The phone will show no response — no boot screen, no charging indicator. Connect the phone to a low-current charger (a standard 5V USB wall adapter, not a fast charger) and leave it for 20–30 minutes without attempting to power it on. Once the BMS detects voltage has recovered above its recovery threshold, the charge IC will engage and the charging indicator will appear.