{"product_id":"compaq-presario-cq42-130tu-replacement-battery-108v-8800mah-li-ion","title":"Compaq Presario CQ42 10.8V Replacement Battery HSTNN-CB0W","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eCompaq Presario CQ42-130TU Series — 10.8V Li-ion Replacement Battery (HSTNN-CB0W)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 10.8V, 8800mAh Li-ion battery for the Compaq Presario CQ42 series, including the CQ42-130TU, CQ42-136TU, CQ42-137TU, CQ42-138TU, and over 225 additional Presario CQ42 variants. It replaces OEM parts HSTNN-CB0W, HSTNN-IB0X, HSTNN-LB0W, and a broad range of cross-compatible HP\/Compaq part numbers listed in the fit table. Voltage is 10.8V and capacity is 8800mAh (95.04Wh).\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCQ42 series compatibility:\u003c\/strong\u003e\n    These Presario models share the same 10.8V three-cell battery bus, connector pinout, and BMS handshake protocol. The HSTNN-CB0W family covers the full CQ42 production run because HP used one battery platform across this chassis generation without changing the SMBus address or connector layout.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell on a CQ42 mainboard and confirmed the BMS completed charge handshake, the SMBus reported state-of-charge correctly, and the protection circuit tripped at the correct low-voltage cutoff without causing an uncontrolled shutdown.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install calibration on the CQ42:\u003c\/strong\u003e\n    After fitting this battery, run the laptop on battery only until it reaches hibernate-cutoff — do not interrupt. Then charge uninterrupted to 100%. This single discharge-charge cycle resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every 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 CQ42 BIOS reports poor battery health after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe CQ42 uses an SMBus fuel gauge IC that stores learned capacity data in EEPROM on the old cell. When you fit a new battery, the BIOS reads stale EEPROM data that does not match the new cell's actual chemistry profile, so it flags health as poor or unknown. This is not a fault with the replacement cell — it is the gauge IC adjusting to fresh chemistry. Running one full discharge-to-hibernate then a full uninterrupted charge gives the fuel gauge IC enough data to rewrite its internal model. After that cycle, the BIOS health indicator should read normal.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCQ42 shutting down at 20–30% charge shown on the gauge\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis symptom appears when the fuel gauge IC has not yet calibrated against the new cell — the percentage on screen is wrong, not the battery. Under full CPU and display load, the cell voltage drops faster than the uncalibrated gauge predicts, and the BMS hits its low-voltage cutoff before the gauge reaches 0%. Run the calibration cycle described in the care tip above. After one complete discharge and recharge, the gauge should track actual cell voltage accurately and the premature shutdowns will stop. If the problem persists after two calibration cycles, check that the BIOS is not enforcing a charge limit — navigate to BIOS power settings and confirm no battery threshold is active.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43410740838490,"sku":"BWCS-HDM4DB-1","price":123.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43410740871258,"sku":"BWCS-HDM4DB-2","price":142.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43410740904026,"sku":"BWCS-HDM4DB-3","price":155.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-HDM4DB-1.webp?v=1779581112","url":"https:\/\/batteryweb.com\/products\/compaq-presario-cq42-130tu-replacement-battery-108v-8800mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}