Toshiba Portege Z30 Replacement Battery PA5136U-1BRS 14.8V
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Toshiba Portege Z30 Replacement Battery PA5136U-1BRS 14.8V - is backordered and will ship as soon as it is back in stock.
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Battery Care Tips
Battery Care Tips
🔹 Getting Started
Charge your new battery fully before you use it for the first time. Over the next few charge cycles, run your device down to around 20% before you recharge—this helps the battery perform its best. After that, charge whenever you need to.
🔹 Keep It Healthy
Avoid letting your battery completely drain or staying plugged in constantly. Both extremes wear it out faster. Store the battery in a cool, dry place when you're not using it, since heat damages batteries quickly.
Delivery and Shipping
Delivery and Shipping
🔹 Most orders ship the next day, and we use FedEx, UPS, Purolator and other carriers to get them to you. Lithium batteries have to ship by ground only, not air or USPS. Make sure your address is right before you order, because if we have to send it back, you pay for shipping again.
Disclaimer
Disclaimer
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🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.
Toshiba Portege Z30 Replacement Battery PA5136U-1BRS 14.8V - is backordered and will ship as soon as it is back in stock.
Voltage
14.8V
Amp
3350mAh
Toshiba Portege Z30 Series — 14.8V Li-Polymer Replacement Battery (PA5136U-1BRS)
This is a 14.8V, 3350mAh (49.58Wh) lithium-polymer replacement battery for the Toshiba Portege Z30 ultrabook. It uses OEM part number PA5136U-1BRS and fits the Z30, Z30-A-12U, Z30-A-M5S, Z30-A1301, and over 250 additional Z30-series variants. Install it when the original cell no longer holds a charge or BIOS flags battery health as degraded.
- Z30-series platform fit: All Z30-A variants share the same 14.8V four-cell Li-Polymer architecture, connector pinout, and BMS handshake protocol — which is why a single part number covers the full production run across regional SKUs.
- Bench tested on actual hardware: We ran this cell through full charge-discharge cycles on a Z30-A unit. The BMS negotiated correctly with the Toshiba EC, charge current stepped down cleanly at the 80% threshold, and the cell reached 100% without voltage fault interruption.
- First-cycle conditioning on the Z30: After fitting, run the laptop on battery until it hibernates at low-battery cutoff, then charge uninterrupted to 100%. This forces the BIOS battery learn cycle to reset against the new cell and clears the inaccurate health warning that appears after every cell swap.
BIOS reporting poor battery health immediately after fitting the PA5136U-1BRS
The Z30's embedded controller reads health data from EEPROM on the battery's BMS board. When a new cell arrives, that EEPROM contains factory default values that don't match the EC's learned profile from the old battery. The EC interprets the mismatch as a degraded cell and flags it in BIOS and Windows battery settings. One complete discharge-to-hibernate followed by a full uninterrupted charge resets the learn cycle and writes fresh calibration data — the health warning clears without any BIOS update or driver change.
Portege Z30 shutting down at 20–30% charge shown on screen
This is a voltage cliff issue, not a fuel gauge error. Under combined CPU and display load, the cell's discharge curve drops steeply in the lower capacity band — voltage falls below the EC's cutoff threshold before the reported percentage reaches zero. The fuel gauge IC is reading state-of-charge against a stale discharge curve from the old cell. Run two full calibration cycles — full discharge to hibernate cutoff, full charge to 100% — so the fuel gauge IC maps its curve against the actual chemistry of the new cell. After the second cycle, the reported percentage at shutdown should align with real cell voltage near 13.2V.
Compatible Models
Replaces Part Numbers
Technical Specifications
Product Highlights
- Brand: Toshiba
- Manufacturer: CS
- Series: Standard
- Color: Black
- Product Type: Li-Polymer
- Battery Type: Li-Polymer
- Warranty: 12 Months
- Bulk Orders: sales@batteryweb.com
Frequently Asked Questions
My Portege Z30 shows the new battery as "0% available (plugged in, charging)" and never moves — what's wrong?
The EC hasn't finished initialising the EEPROM handshake with the new cell's BMS. Shut the laptop down completely, remove the AC adapter for 30 seconds, reconnect power, and boot. This forces the embedded controller to re-poll the battery rather than reading cached data from the previous cell. If the percentage still doesn't update after one full charge cycle, confirm the battery connector is fully seated — the Z30's slim connector can appear locked while one pin is still floating.
Windows reports this battery as 49Wh but my old battery showed 60Wh — is the replacement underspecced?
The Wh figure Windows reports pulls from the EEPROM "design capacity" field on the BMS board, not from a live measurement. Factory EEPROM on replacement cells is written to the rated chemistry spec — 14.8V × 3350mAh = 49.58Wh — which is the correct value for PA5136U-1BRS. If the original cell had been reconditioned or was a higher-capacity variant, its EEPROM would have held a different figure. The replacement cell is not underspecced; the Wh reading is accurate for this part number.
The Z30 charges fine but the fuel gauge jumps erratically — shows 74%, then 91%, then drops to 55% within minutes.
The fuel gauge IC is running its impedance tracking algorithm against discharge-curve data it learned from the old, degraded cell. It cannot accurately map state-of-charge on a new cell until it completes calibration cycles. Run the battery down to hibernate cutoff without interruption, then charge fully to 100% twice in a row. After the second full cycle the fuel gauge IC rewrites its internal model against the new cell's actual curve, and the percentage reading stabilises.
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