UTStarcom BTR-8030 Replacement Battery 3.7V 800mAh Li-ion

UTStarcom BTR-8030 — 3.7V Li-ion Replacement Battery (BTR-8030)

This is a 3.7V, 800mAh Li-ion replacement battery carrying OEM part numbers BTR-8030 and BTR-8030B. It fits UTStarcom mobile phones that originally shipped with those part numbers. Capacity is 2.96Wh at 3.7V nominal — use the product data, not the original battery label, to confirm fitment.

• BTR-8030 and BTR-8030B platform: Both part numbers share the same 3.7V cell configuration, connector pinout, and BMS handshake protocol. UTStarcom released the B-suffix variant with a minor BMS firmware revision — electrically they are interchangeable at this voltage rail.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the bench. The BMS accepted charging current correctly, reported cell voltage accurately to the charge IC, and held voltage above the cutoff threshold throughout the discharge curve without tripping the protection circuit.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging for one complete discharge-charge cycle. The fuel gauge IC in these UTStarcom phones calibrates against the cell's discharge curve. Skipping this step with a fresh, uncalibrated cell can cause the reported percentage to drift by 10–15% before the first full cycle completes.

Sudden shutdown at 20–30% on the BTR-8030 replacement cell

UTStarcom phones using this battery draw a sharp current spike when the modem transmits or the screen refreshes at full brightness. A new cell with a slightly different internal resistance curve can hit the BMS low-voltage cutoff before the OS fuel gauge reaches 0%. The phone reads 25% remaining but the cell voltage has already dropped below the 3.0V protection threshold under that instantaneous load. One full calibration cycle — drain to auto-shutdown, then charge uninterrupted to 100% — resets the coulomb counter and eliminates most premature cutoffs.

Phone will not power on after the BTR-8030 cell sat in storage

Li-ion cells self-discharge roughly 2–3% per month. A BTR-8030 battery stored for six months or more can drop below 2.5V per cell, triggering BMS lockout — the protection circuit disconnects the cell entirely to prevent damage. The phone will not respond to the power button or show a charging indicator on a standard cable. Connect it to a 5V USB charger and leave it undisturbed for 20–30 minutes; the BMS trickle-charges the cell back above 2.7V before allowing normal charge current. Once the charging LED activates, charge fully to 4.2V before first boot.