{"product_id":"simvalley-sp-40-replacement-battery-37v-1200mah-li-ion","title":"Simvalley SP-40 Replacement Battery 3.7V 1200mAh PX-3423","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSimvalley SP-40 \/ SP-60 — 3.7V Li-ion Replacement Battery (PX-3423)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V 1200mAh Li-ion cell for the Simvalley SP-40 and SP-60 smartphones. It replaces OEM part numbers PX-3423 and PX-3423-675. Swap it in when the original cell no longer holds a usable charge or causes unexpected shutdowns.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSP-40 and SP-60 shared platform:\u003c\/strong\u003e\n    Both handsets run the same 3.7V voltage rail and use an identical physical connector and cell footprint at 63.60 × 40.00 × 4.45mm. The BMS handshake is compatible across both models, so one cell covers the pair.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through a full discharge-charge sequence on the SP-40 and monitored BMS cutoff behaviour at low voltage. The protection circuit tripped correctly at the low-voltage threshold and accepted a charge without fault flags on the first cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After installation, disable fast charging and run one complete discharge down to auto-off, then charge to 100% without interruption. This lets the fuel gauge IC map its coulomb counter to the new cell's discharge curve before high-current charging begins.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the SP-40 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe SP-40 uses a fuel gauge IC that stores a learned discharge curve from the original cell. When you fit a new cell, that stored curve no longer matches actual cell behaviour, so the reported percentage drifts from reality. The gauge reads voltage and estimates state-of-charge against old calibration data. One full discharge-charge cycle forces the coulomb counter to reset and relearn against the new cell. After that cycle, percentage readout stabilises.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the SP-40 after replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis is a voltage cliff, not a capacity fault. When the modem transmits or the screen hits peak brightness, the cell must deliver a short high-current burst. If the cell voltage sags below the BMS cutoff threshold under that load — even while the gauge still reads 20–30% — the phone shuts off to protect the circuit. Let the phone power back on and check the resting voltage in the battery settings menu; a reading below 3.5V under no-load confirms the cell is discharging non-linearly. Run one full calibration cycle first — if shutdowns persist after that, check that the battery contacts are fully seated and clean.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43404288131162,"sku":"BWCS-SSP600SL-1","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43404288163930,"sku":"BWCS-SSP600SL-2","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43404288196698,"sku":"BWCS-SSP600SL-3","price":27.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SSP600SL-1.webp?v=1779369658","url":"https:\/\/batteryweb.com\/products\/simvalley-sp-40-replacement-battery-37v-1200mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}