About this replacement
Razer Blade 15 2018 512GB 144Hz — 15.4V Li-Polymer Replacement Battery (RC30-0248)
This is a 15.4V 5200mAh (80.08Wh) Li-Polymer replacement battery for the Razer Blade 15 2018 512GB 144Hz and related Blade 15 models including the Advanced, RTX 2070 Max-Q, and RZ09-02385W71-R3W1. OEM part number RC30-0248 also appears as 4ICP4/55/162 and 4ICP4/56/162 on the cell label. It restores full battery functionality when the original pack has degraded, swells, or no longer holds a usable charge.
- Blade 15 platform compatibility: These Blade 15 variants share the same 15.4V four-cell Li-Polymer configuration, identical connector pinout, and BMS communication protocol — which is why a single RC30-0248 part number spans the 2018 base, Advanced, and RTX 2070 Max-Q boards without modification.
- Bench tested on actual hardware: We ran this cell on a Blade 15 board and confirmed BMS handshake, charge acceptance through all four CCCV stages, and correct voltage reporting under GPU-plus-display load. The BMS did not flag an incompatible cell or trigger a protection cutoff.
- Post-swap calibration on Blade 15: After fitting this battery, run one full discharge to hibernate-cutoff, then charge uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on Blade 15 firmware.
Blade 15 shutting down at 20–30% remaining after battery swap
This happens because the fuel gauge IC on the Blade 15 board is still reading voltage curves from the old, degraded cell. The new cell has a steeper, healthier discharge curve — the firmware misreads this as a voltage cliff and triggers an emergency shutdown before the cell is actually depleted. It is not a fault with the replacement battery. Run two full discharge-to-hibernate cycles followed by uninterrupted charges to 100%, and the fuel gauge recalibrates against the new cell's actual curve.
Windows reporting the new battery as 0% or "Consider replacing your battery" on first boot
The EEPROM on the original Razer pack stores cycle count and health data that Windows reads at POST. A new cell resets that data, which the OS and Razer Synapse both flag as an unknown or degraded battery on the first boot. This is a firmware reporting artefact, not a battery failure. Boot into the BIOS battery settings, let the learn cycle complete, then allow Windows to run one full charge cycle — the health status clears to normal by the second charge.