CECT V10 Replacement Battery 3.7V 1200mAh Li-ion

CECT V10 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 1200mAh Li-ion cell that replaces the original battery in the CECT V10 candybar smartphone. It fits the V10 directly and restores normal device operation when the original cell has degraded or failed to hold charge. Capacity figures come from the product data: 1200mAh, 4.44Wh.

• V10 platform fitment: The CECT V10 uses a compact 53.00 × 33.90 × 5.70mm cell at 3.7V nominal. This replacement matches those physical dimensions and the voltage rail the phone's charge IC expects. A mismatch in cell thickness is the most common fitment failure on candybar phones — this cell sits flush under the back cover.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench and monitored BMS cutoff behaviour. The protection circuit tripped correctly at the low-voltage threshold and resumed normally after reconnection. No abnormal heat was observed at the charge IC during the first cycle.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC build an accurate discharge curve against the new cell before high-current charging begins on an uncalibrated reference.

Sudden shutdown at 20–30% on the replacement cell

The CECT V10's fuel gauge IC was calibrated to the discharge curve of the original aged cell. A fresh 1200mAh cell has a steeper voltage cliff at the low end than a degraded one. When the modem transmits or the screen peaks in brightness, current draw spikes and the new cell's voltage dips sharply — enough to trigger the low-voltage cutoff even though the reported percentage is still above 20%. One full discharge-to-shutdown followed by an uninterrupted charge to 100% lets the coulomb counter re-anchor its curve to the new cell.

Phone warm near the battery compartment on the first charge cycle

A brand-new cell arrives with higher internal impedance than a broken-in one. The charge IC pushes current into that higher resistance, and the resulting heat is normal on cycle one. If the phone is warm to the touch but not hot, this is expected behaviour and typically resolves after the first full cycle. If the case becomes hot enough to be uncomfortable, disconnect immediately and check that the replacement cell's dimensions are not causing pressure against the back cover. Normal operating temperature on cycle two should drop noticeably.