{"product_id":"doro-primo-406-replacement-battery-37v-1200mah-li-ion","title":"Doro Primo 406 Replacement Battery RCB01P01 3.7V 1200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eDoro Primo 406 \/ 413 \/ 414 — 3.7V Li-ion Replacement Battery (RCB01P01)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1200mAh Li-ion cell for the Doro Primo 406, Primo 413, and Primo 414 — basic mobile phones built for senior users. The OEM part numbers RCB01P01, RCB413, and RCBNTC01 all cross to this cell. Physical dimensions are 53.45 × 36.88 × 5.75mm — measure your original before fitting.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePrimo 406, 413, and 414 compatibility:\u003c\/strong\u003e\n    All three models share the same battery bay dimensions, connector pinout, and NTC thermistor line. The charge IC on each handset reads the NTC to regulate current — this cell includes that thermistor circuit, so the charger behaves the same as with the original.\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 and load discharge on a Primo 413. The BMS held stable cutoff at 3.0V under screen-on load and accepted charge without thermal fault. The NTC line stayed within spec throughout.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first cycle:\u003c\/strong\u003e\n    On first use after fitting, run one complete discharge down to automatic shutdown, then charge uninterrupted to 100% before normal use. The Primo's fuel gauge IC needs one full cycle against the new cell's discharge curve — skip this and the percentage counter will read inaccurately for the first week.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Primo 406 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Primo 406 uses a simple coulomb-counting fuel gauge IC that was calibrated to the original cell's impedance and discharge curve. Drop in a fresh cell and that learned curve no longer matches reality. The gauge will typically over-report early on — showing 40% when the phone is close to shutdown — until it relearns the endpoints. One full discharge-to-cutoff followed by an uninterrupted charge to 100% resets the counter against the new cell. After that cycle, percentage readings stabilise.\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 fuel gauge IC hasn't yet mapped the new cell's voltage cliff. Li-ion cells drop voltage sharply below roughly 3.4V under load — the phone's protection circuit cuts power before the gauge reaches zero. The Primo's screen and RF modem draw enough current during a call or bright-screen use to trigger this cliff earlier than idle readings suggest. Fix it by completing the recalibration cycle described above; the phone needs to see the cell reach its actual low-voltage cutoff — 3.0V — at least once before the gauge adjusts its shutdown threshold.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43404239503450,"sku":"BWCS-DEP413SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43404239536218,"sku":"BWCS-DEP413SL-2","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43404239568986,"sku":"BWCS-DEP413SL-3","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DEP413SL-1.webp?v=1779369448","url":"https:\/\/batteryweb.com\/products\/doro-primo-406-replacement-battery-37v-1200mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}