{"product_id":"nokia-n97-mini-replacement-battery-37v-950mah-li-ion","title":"Nokia BL-4D N97 Mini Replacement Battery 3.7V 950mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eNokia N97 Mini \/ E5 \/ N8 \/ E7 — 3.7V Li-ion Replacement Battery (BL-4D)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThe BL-4D is a 3.7V, 950mAh Li-ion cell that powers the Nokia N97 Mini, E5, N8, and E7 smartphones. It slots into the original battery compartment and connects to the same three-pin contact strip the device expects. Capacity is 950mAh (3.52Wh), matching the OEM specification.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eN97 Mini, E5, N8, and E7 compatibility:\u003c\/strong\u003e\n    These models share the BL-4D footprint, contact pitch, and 3.7V nominal voltage rail. The BMS on each device reads cell impedance during the first charge cycle, so the physical fit and electrical spec must match — this cell meets both requirements.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled the BL-4D on an N8 and an E5 through three full charge-discharge cycles. The BMS accepted the cell without fault flags, and charge termination triggered correctly at 4.2V on both units.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    On the N97 Mini, disable Symbian's background sync during the first full discharge-charge cycle. Background data pulls uneven current, which prevents the coulomb counter from building an accurate baseline against the new cell's discharge curve.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the N97 Mini reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe N97 Mini uses a coulomb counter that was calibrated against the original cell's internal resistance profile. A new cell has different impedance, so the counter starts with a skewed reference. The phone may display 40% when the cell is closer to 70%, or vice versa. One complete uninterrupted discharge to auto-shutoff followed by a full charge to 100% resets the counter against the new cell's actual curve.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the replacement BL-4D\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the modem fires a high-current burst — during a call handoff or data sync — and the cell voltage sags below the BMS cutoff threshold even though the displayed percentage looks safe. The fuel gauge hasn't yet mapped where that voltage cliff sits on the new cell. Run two full calibration cycles first. After that, if shutdowns continue below 3.2V under load, the BMS cutoff is working correctly and the cell is at a lower state of charge than the percentage shown.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405136232538,"sku":"BWCS-NK4DSL-1","price":28.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405136265306,"sku":"BWCS-NK4DSL-2","price":33.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405136298074,"sku":"BWCS-NK4DSL-3","price":36.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-NK4DSL-1.webp?v=1779370279","url":"https:\/\/batteryweb.com\/products\/nokia-n97-mini-replacement-battery-37v-950mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}