{"product_id":"sigmatel-fxd-6100-replacement-battery-37v-1050mah-li-ion","title":"Sigmatel FXD 6100 Replacement Battery 3.7V 1050mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSigmatel FXD 6100 — 3.7V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1050mAh Li-ion replacement battery for the Sigmatel FXD 6100 smartphone. It fits directly into the FXD 6100 and restores full power to a device suffering from a degraded or failed original cell. Capacity is 1050mAh (3.89Wh) as specified for this model.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eFXD 6100 fit:\u003c\/strong\u003e\n    This battery matches the voltage rail and physical dimensions (53.00 × 33.90 × 5.60mm) of the original FXD 6100 cell. The connector and BMS interface align with what the phone's charge IC expects, so the device recognises the new cell 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 bench. The BMS held stable cutoff thresholds at both ends, with no false tripping under simulated screen and modem load.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle fuel gauge recalibration:\u003c\/strong\u003e\n    On first use after installation, disable fast charging if the option is available and run one complete discharge-charge cycle. The FXD 6100's fuel gauge IC is calibrated to the old cell's discharge curve — one full cycle lets it map the new cell's behaviour before resuming high-current charging.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the FXD 6100 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe FXD 6100 uses a fuel gauge IC that tracks charge state using a coulomb counter trained on the original cell's discharge curve. When you swap in a new cell, the counter starts from stale reference data. This causes the OS to display percentages that don't reflect actual charge state — you may see jumps of 10–15% in either direction. One full discharge down to automatic shutdown, followed by a complete 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 cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the fuel gauge IC still holds the old cell's voltage-versus-capacity mapping. The new cell hits a steeper voltage cliff under modem or display load — the phone's hardware protection circuit cuts power before the reported percentage reaches zero. It's not a faulty battery. Force a full discharge cycle: let the phone shut itself off naturally, then charge uninterrupted to 4.2V (100%). After one cycle, the shutdown point shifts back to the correct low-voltage threshold.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405113884762,"sku":"BWCS-HFC250SL-1","price":21.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405113917530,"sku":"BWCS-HFC250SL-2","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405113950298,"sku":"BWCS-HFC250SL-3","price":26.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-HFC250SL-1.webp?v=1779369992","url":"https:\/\/batteryweb.com\/products\/sigmatel-fxd-6100-replacement-battery-37v-1050mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}