{"product_id":"cyrus-cs20-replacement-battery-37v-3400mah-li-ion","title":"Cyrus CS20 Replacement Battery 3.7V 3400mAh CYR10022","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eCyrus CS20 — 3.7V Li-ion Replacement Battery (CYR10022)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 3400mAh Li-ion replacement battery for the Cyrus CS20 smartphone. It fits directly in place of the original CYR10022 cell. Use this when the original battery no longer holds a useful charge or the phone shuts down unexpectedly under load.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCS20 fitment:\u003c\/strong\u003e\n    The CS20 uses a fixed connector pinout and a specific cell footprint (69.00 × 47.70 × 10.40mm). This replacement matches both, so the BMS handshake between the charge IC and the cell completes without errors on first boot.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through charge and discharge on the CS20 platform. The BMS accepted the cell, charge termination triggered correctly at 4.2V, and no thermal events occurred during the fast-charge phase.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After fitting this cell, disable fast charging and run one full discharge-charge cycle at standard rate. The CS20's fuel gauge IC is calibrated to the old cell's discharge curve — one slow cycle lets it remap against the new cell before fast charging pushes higher current into an uncalibrated state.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the CS20 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe CS20 uses a coulomb counter in its fuel gauge IC to estimate state of charge. That counter is calibrated against the discharge curve of the original cell. When a new cell goes in, the stored curve no longer matches actual cell behaviour, so the percentage readout drifts — sometimes by 15–20%. One complete discharge to cutoff followed by a full charge to 4.2V resets the reference point. After that cycle, percentage accuracy returns to normal.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the replacement cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the modem or display draws a high current pulse and the cell voltage drops below the BMS cutoff threshold faster than the fuel gauge expects. The CS20's fuel gauge still shows 20–30% because it hasn't updated, but the actual cell voltage has already sagged past 3.2V under load. The fix is to complete two full discharge-charge cycles so the coulomb counter can build an accurate low-end voltage map. If shutdowns continue past three cycles, check that the battery connector is fully seated — a partially connected cell increases internal resistance and worsens voltage sag under load.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43392102891610,"sku":"BWCS-CYS200SL-1","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43392102924378,"sku":"BWCS-CYS200SL-2","price":29.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43392102957146,"sku":"BWCS-CYS200SL-3","price":32.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-CYS200SL-1.webp?v=1779143796","url":"https:\/\/batteryweb.com\/products\/cyrus-cs20-replacement-battery-37v-3400mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}