{"product_id":"asus-u30jc-replacement-battery-148v-4400mah-li-ion","title":"Asus U30JC Replacement Battery 14.8V 4400mAh Li-ion A31-UL30","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAsus U30JC \/ U35 \/ U45 Series — 14.8V Li-ion Replacement Battery (A31-UL30 \/ A32-UL30)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 14.8V, 4400mAh (65.12Wh) Li-ion replacement battery for the Asus U30JC and related U-series notebooks. It covers the U30JC, U35, U35JC, U45, and several hundred additional U-series variants that share the same OEM battery platform. Replaces part numbers A31-UL30 through A42-UL80 across the full UL30, UL50, and UL80 sub-families.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eU-series battery platform compatibility:\u003c\/strong\u003e\n    The UL30, UL50, and UL80 lines share a unified 14.8V four-cell battery bay, connector pinout, and BMS handshake protocol. That is why a single SKU covers over 250 models — the power rail, latch geometry, and communication bus are identical across the range.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell on a U35JC and monitored BMS communication through the SMBus interface. The protection circuit responded correctly to over-discharge cutoff and charge termination at 16.8V. No thermal events occurred across three full cycles.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install calibration on U-series:\u003c\/strong\u003e\n    After fitting this battery, run the laptop on battery power until it hibernates on low charge, then charge uninterrupted to 100% without waking the system. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears immediately after any cell swap.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the U30JC BIOS reports poor battery health after a new cell install\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Asus U-series BIOS reads EEPROM data embedded in the original battery's fuel gauge IC to determine health status. When a replacement cell is fitted, the EEPROM values do not match the BIOS's stored reference — so Windows and the BIOS both flag the battery as degraded or unknown even though the cell is new. This is not a hardware fault. Running a full discharge-to-hibernate followed by an uninterrupted charge to 100% forces the BIOS to rewrite its battery reference data against the new cell's actual charge curve. After one or two of these learn cycles, the health indicator normalises.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eLaptop shuts down at 20–30% charge shown on the gauge\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis symptom points to a voltage cliff under load, not a calibration issue. When the CPU and display draw peak current simultaneously, cell voltage drops sharply below the BMS cutoff threshold — even while the fuel gauge still shows capacity remaining. The fuel gauge IC has not yet mapped the new cell's discharge curve, so it misreads remaining capacity. Run two or three full discharge and charge cycles to let the fuel gauge IC recalibrate against the replacement cell; after that, the shutoff point should track actual depletion accurately down toward 3.0V per cell.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43410740543578,"sku":"BWCS-AUL80NB-1","price":112.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43410740576346,"sku":"BWCS-AUL80NB-2","price":128.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43410740609114,"sku":"BWCS-AUL80NB-3","price":140.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-AUL80NB-1.webp?v=1779581091","url":"https:\/\/batteryweb.com\/products\/asus-u30jc-replacement-battery-148v-4400mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}