{"product_id":"toshiba-tecra-z40-a-17k-replacement-battery-144v-3800mah-li-ion","title":"Toshiba Tecra Z40-A-17K Replacement Battery PA5149U-1BRS 14.4V","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eToshiba Tecra Z40\/Z50-A Series — 14.4V Li-ion Replacement Battery (PA5149U-1BRS)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 14.4V, 3800mAh (54.72Wh) Li-ion replacement battery for the Toshiba Tecra Z40-A-17K and the broader Tecra Z40\/Z50-A and Z40-B series. It matches the OEM part number PA5149U-1BRS and uses the same connector and BMS handshake as the original cell. Voltage, capacity, and physical dimensions align directly with what the Z40-A-17K chassis expects.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eTecra Z40\/Z50-A and Z40-B compatibility:\u003c\/strong\u003e\n    These models share the same 14.4V power rail, identical four-pin connector, and the same BMS communication protocol. The BIOS on all variants reads the battery via the same EEPROM query, so one cell covers the full platform without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell on a Tecra Z40-A under full CPU and display load. The BMS held voltage above the 10.8V cutoff threshold throughout discharge, and charge acceptance reached 100% without triggering the BIOS charge-limit flag.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBIOS learn cycle after install:\u003c\/strong\u003e\n    After fitting this battery, run a single 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 any cell swap on this platform.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Tecra Z40-A BIOS reports poor health immediately after a battery swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Z40-A BIOS reads charge cycle count, rated capacity, and health state directly from the battery's EEPROM at boot. A new cell carries fresh EEPROM data that doesn't match the learned values the BIOS stored from the old battery. Until a full discharge-to-hibernate and uninterrupted recharge cycle is completed, the BIOS treats the mismatch as a fault condition. After one full calibration cycle, the health status updates to normal and the warning clears.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eTecra Z40-A shutting down at 20–30% charge remaining\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the cell cannot hold its voltage above the system cutoff threshold under combined CPU and display load — the fuel gauge shows percentage remaining, but voltage collapses faster than the gauge predicts. It is almost always a fuel gauge IC calibration issue on cycles 1–3 with a new cell, not a faulty battery. The gauge IC needs to observe a full discharge curve to map the new cell's voltage-to-capacity profile accurately. Run the Z40-A fully down to automatic hibernate at least twice, charging to 100% each time, and the shutdowns will stop.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43410735005786,"sku":"BWCS-TOZ400NB-1","price":111.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43410735038554,"sku":"BWCS-TOZ400NB-2","price":127.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43410735071322,"sku":"BWCS-TOZ400NB-3","price":139.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-TOZ400NB-1.webp?v=1779580625","url":"https:\/\/batteryweb.com\/products\/toshiba-tecra-z40-a-17k-replacement-battery-144v-3800mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}