{"product_id":"fujitsu-stylistic-q665-replacement-battery-111v-3400mah-li-polymer","title":"Fujitsu Stylistic Q665 Replacement Battery 11.1V 3400mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eFujitsu Stylistic Q665 \/ Q738 \/ Q739 — 11.1V Li-Polymer Replacement Battery (CP690859)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is an 11.1V, 3400mAh (37.74Wh) Li-Polymer replacement battery for the Fujitsu Stylistic Q665, Q738, Q739, and Q616 series detachable tablets. It replaces OEM part numbers CP690859, CP690859-01, CP700540-01, FPB0326S, FPB0349S, and FPCBP479. Install it when the original cell has degraded, lost significant capacity, or stopped holding charge altogether.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eStylistic Q-series compatibility:\u003c\/strong\u003e\n    The Q665, Q738, Q739, and Q616 all share the same 11.1V cell architecture, connector pinout, and BMS handshake protocol — that is why one part number covers all four platforms.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through charge, full discharge to hibernate cutoff, and a second full charge. The BMS reported correct voltage at each stage and did not trip the protection circuit under sustained load.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle calibration on the Stylistic Q-series:\u003c\/strong\u003e\n    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 these tablets.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Stylistic Q665 shuts down at 20–30% after a battery swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe fuel gauge IC still holds voltage-curve data from the old, degraded cell. When the new cell reaches a voltage point that the old profile mapped to 20–30% remaining, the firmware calls a low-voltage shutdown — even though the new cell has capacity left. Running one full discharge-to-hibernate, then a full uninterrupted charge forces the gauge IC to relearn the new cell's actual voltage curve. After two to three cycles the shutoff point tracks correctly.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS reporting battery health as poor immediately after installation\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Stylistic Q-series BIOS reads EEPROM data written by the original factory cell, including cycle count and rated Wh. A replacement cell presents different EEPROM values, which the BIOS flags as degraded or unknown health. This is not a fault with the new cell — it is a data mismatch. Run the battery learn cycle described above; on most Q-series units the health status updates to normal within one full charge cycle after calibration.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43409559617626,"sku":"BWCS-FUQ738NB-1","price":85.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43409559650394,"sku":"BWCS-FUQ738NB-2","price":101.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43409559683162,"sku":"BWCS-FUQ738NB-3","price":113.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-FUQ738NB-1.webp?v=1779580013","url":"https:\/\/batteryweb.com\/products\/fujitsu-stylistic-q665-replacement-battery-111v-3400mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}