{"product_id":"asus-r2h-replacement-battery-74v-3430mah-li-polymer","title":"Asus R2H Replacement Battery C21-R2 7.4V 3430mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAsus R2H \/ R2E \/ R2Hv — 7.4V Li-Polymer Replacement Battery (C21-R2)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 7.4V, 3430mAh (25.38Wh) lithium-polymer replacement battery for the Asus R2H, R2E, and R2Hv convertible tablet-laptop. The C21-R2 fits the slim battery bay on all three variants with the original connector orientation and BMS pinout. Install it as a direct swap when the original cell no longer holds a useful charge.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eR2H, R2E, and R2Hv compatibility:\u003c\/strong\u003e\n    All three models share the same battery bay dimensions, 7.4V two-cell architecture, and BMS handshake protocol — that is why one part number covers the whole R2 line. The connector and locking tab are identical across the series.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through full charge-discharge sequences and confirmed the BMS communicates charge state correctly to the host system. Capacity read-back at 3430mAh matched product spec within normal cell tolerance.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install calibration for the R2H:\u003c\/strong\u003e\n    After fitting, run the tablet to hibernate-cutoff on battery only, then charge uninterrupted to 100% without waking the device. This resets the BIOS battery learn cycle and clears the inaccurate health warning that appears after every cell swap on the R2 platform.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBIOS reporting poor battery health immediately after fitting the C21-R2\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe R2H BIOS reads health data from the battery's EEPROM, which stores cycle count and rated capacity from the previous cell. A new cell ships with factory EEPROM defaults that do not match your system's logged history, so the BIOS flags a mismatch as poor health. This is a data conflict, not a fault with the replacement cell. Run one full discharge-to-hibernate followed by an uninterrupted charge to 100% to let the BIOS rewrite its battery learn table against the new cell's actual readings. After two or three cycles the health indicator should normalise.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eFuel gauge jumping erratically for the first few charge cycles\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe fuel gauge IC in the R2H calibrates its internal model against the specific impedance curve of the installed cell. Swap the cell and that model is mismatched — the gauge can read 60% one moment and drop to 35% shortly after under light load. This is not a defective battery; it is the IC recalculating against unfamiliar cell data. Run two or three full discharge-to-charge cycles without interrupting the charge phase and the gauge IC will rebuild an accurate model. After the third cycle, readings should track linearly from 100% down to the hibernate cutoff near 3.0V per cell.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43410854117466,"sku":"BWCS-AUR2NB-1","price":58.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 2 Year","offer_id":43410854150234,"sku":"BWCS-AUR2NB-2","price":68.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 3 Year","offer_id":43410854183002,"sku":"BWCS-AUR2NB-3","price":76.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-AUR2NB-big.webp?v=1779581376","url":"https:\/\/batteryweb.com\/products\/asus-r2h-replacement-battery-74v-3430mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}