BLU Studio J5 Replacement Battery 3.8V 2300mAh C795344230L

BLU Studio J5 / S0290UU — 3.8V Li-ion Replacement Battery (C795344230L)

This is a 3.8V, 2300mAh Li-ion battery for the BLU Studio J5 (model S0290UU). It replaces OEM part C795344230L and restores power to the handset when the original cell has degraded or failed. Dimensions are 79.48 × 53.20 × 4.90mm — measure your existing cell before installing if you are unsure.

• Studio J5 and S0290UU compatibility: Both model references point to the same physical handset. They share the same battery bay dimensions, 3.8V supply rail, and BMS connector pinout — one cell covers both.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Studio J5 platform. The BMS accepted the handshake without fault flags, and the charge IC brought the cell up to full voltage without thermal events.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one full discharge-to-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before the OS starts reporting capacity figures you can trust.

Sudden shutdown at 20–30% on the Studio J5 after a cell swap

The Studio J5 fuel gauge IC holds a discharge curve learned from the original cell. When a new cell goes in, that stored curve no longer matches real voltage behaviour. At around 20–30% reported charge, the cell voltage drops below what the modem and display draw can sustain, and the phone cuts off to protect the circuit. This is a calibration gap, not a faulty battery. One full discharge — run the phone down until it shuts itself off — followed by an uninterrupted charge to 100% re-anchors the coulomb counter to the new cell. After that cycle, shutdowns at false-high percentages stop.

Phone not powering on after the replacement cell sat in storage

Li-ion cells self-discharge in storage. If the C795344230L cell dropped below roughly 2.5V while waiting on a shelf, the BMS may have entered lockout mode to prevent damage — the phone will show nothing when you press power. Connect the phone to a wall charger, not a PC port, and leave it for 15–20 minutes before attempting to power on. A wall charger delivers enough current to nudge the BMS out of lockout; USB ports on computers often cannot. If the charging indicator appears, the BMS has recovered — continue charging to at least 3.7V before booting.