{"product_id":"olympia-happy-ii-replacement-battery-37v-900mah-li-ion","title":"Olympia Happy II Replacement Battery ICP423450 3.7V 900mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eOlympia Happy II \/ 2218 — 3.7V Li-ion Replacement Battery (ICP423450)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 900mAh Li-ion cell for the Olympia Happy II and 2218 mobile phones. It replaces OEM part ICP423450 when the original cell no longer holds a charge or fails to power the handset. Dimensions are 53.35 × 36.80 × 4.50mm — verify against your existing cell before fitting.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eHappy II and 2218 compatibility:\u003c\/strong\u003e\n    Both models share the same PCB connector, cell footprint, and 3.7V nominal voltage rail. The BMS handshake is identical across the two, so this cell fits either without hardware modification.\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 Happy II platform. The BMS accepted the cell without fault flags, and protection cutoffs triggered correctly at both low-voltage and over-charge thresholds.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    On first use after fitting, disable any fast-charge mode and run one full discharge-to-charge cycle. This lets the fuel gauge IC build an accurate discharge curve against the new cell before high-current charging is applied to an uncalibrated cell.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the Olympia Happy II after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens because the phone's fuel gauge IC is still using the discharge curve it mapped to the old, degraded cell. When the new cell hits a voltage point the IC associates with near-empty, it pulls the shutdown signal even though real capacity remains. The fix is a full uninterrupted discharge to auto-off, followed by a full charge without interruption. After one complete cycle the coulomb counter recalibrates and the percentage readout stabilises.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePhone not powering on after the replacement cell sat in storage\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells self-discharge in storage. If the cell dropped below approximately 2.5V, the BMS enters lockout to prevent damage and will not pass current to the phone. Connect the phone to a wall charger — not a USB hub — and leave it for 15–20 minutes without pressing the power button. Most BMS circuits on this class of phone require a trickle pre-charge pulse to exit lockout before normal charging can resume. If the charge LED does not activate within 30 minutes, check the charger output is at least 5V 500mA.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43391797952602,"sku":"BWCS-OYL200SL-1","price":33.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43391797985370,"sku":"BWCS-OYL200SL-2","price":39.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43391798018138,"sku":"BWCS-OYL200SL-3","price":43.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-OYL200SL-1.webp?v=1779142182","url":"https:\/\/batteryweb.com\/products\/olympia-happy-ii-replacement-battery-37v-900mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}