{"product_id":"thunderobot-st-plus-replacement-battery-111v-4400mah-li-ion","title":"Thunderobot ST-PLUS Replacement Battery 11.1V 4400mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eThunderobot ST-PLUS Series — 11.1V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is an 11.1V, 4400mAh (48.84Wh) Li-ion battery for the Thunderobot ST-PLUS, ST-PLUS TB, PLUS-U5G, and PLUS-U5F laptops. It replaces a degraded or failed original cell and restores the notebook's ability to run away from mains power. Voltage and connector spec match the original pack exactly.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eST-PLUS platform compatibility:\u003c\/strong\u003e\n    The ST-PLUS, ST-PLUS TB, PLUS-U5G, and PLUS-U5F share the same 11.1V three-cell configuration, connector pinout, and BMS communication protocol — which is why one cell fits all of them.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell through charge and discharge cycles on ST-PLUS hardware. The BMS handshake completed without fault codes, and the pack held voltage across the full discharge curve without sagging early.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install calibration cycle:\u003c\/strong\u003e\n    After fitting this battery, run the laptop on battery until it hibernates at low charge, then charge it uninterrupted to 100%. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS reporting battery health as poor after replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Thunderobot BIOS reads health data stored in the old cell's EEPROM and compares it against the new pack. When the values don't match its learned baseline, it flags the battery as degraded even though the cell is new. This is not a fault with the replacement — it's a calibration gap. Run one full discharge-to-hibernate cycle followed by a full uninterrupted charge, and the BIOS will rewrite its health baseline against the new cell's actual data.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eLaptop shutting down at 20–30% charge shown\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the fuel gauge IC's capacity model still reflects the old cell's degraded chemistry. Under full CPU and display load, the new cell's actual voltage doesn't match where the gauge thinks it is — so the laptop cuts power before the battery is genuinely empty. Run two to three full discharge and charge cycles to let the fuel gauge IC recalibrate against the new cell. After calibration, the reported percentage and actual cutoff voltage — around 9V — should align correctly.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43409601757274,"sku":"BWCS-CLN855NB-1","price":73.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43409601790042,"sku":"BWCS-CLN855NB-2","price":86.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43409601822810,"sku":"BWCS-CLN855NB-3","price":95.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-CLN855NB-1.webp?v=1779580170","url":"https:\/\/batteryweb.com\/products\/thunderobot-st-plus-replacement-battery-111v-4400mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}