{"product_id":"kazam-trooper-x40-replacement-battery-37v-1600mah-li-ion","title":"KAZAM Trooper X4.0 Replacement Battery KAX10 3.7V 1600mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eKAZAM Trooper X4.0 — 3.7V Li-ion Replacement Battery (KAX10)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1600mAh Li-ion cell that directly replaces the original battery in the KAZAM Trooper X4.0 smartphone. It fits the Trooper X4.0 only — confirm your model before ordering. Capacity figures come from the product data, not estimates.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eTrooper X4.0 fit:\u003c\/strong\u003e\n    The X4.0 uses a fixed connector pinout and a BMS that checks cell voltage at boot. This cell matches that voltage rail and connector layout, so the BMS handshake completes on first power-on without triggering a low-voltage lockout.\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 discharge on the bench. The BMS accepted charge current without fault flags, and the protection circuit triggered correctly at the low-voltage cutoff threshold.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle fuel gauge reset:\u003c\/strong\u003e\n    On first use after installation, disable fast charging and run one complete discharge-charge cycle. The Trooper X4.0's fuel gauge IC was calibrated to the old cell's discharge curve — one full cycle gives it new reference points before any high-current charge session begins.\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 Trooper X4.0 after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens because the fuel gauge IC still holds the discharge curve of the old, degraded cell. When the new cell hits a voltage point the IC maps to \"20% remaining,\" the actual cell voltage under modem or screen load drops faster than the old curve predicted. The phone interprets this as a voltage cliff and shuts down to protect the hardware. One full discharge-charge cycle — draining to auto-off and charging uninterrupted to 100% — rewrites the IC's reference curve to match the new cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePhone won't power on after sitting in storage with a flat battery\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells stored fully discharged can drop below 2.5V per cell, which trips the BMS into a deep-discharge lockout — a hard protection state that blocks normal boot. Plugging in a charger may show nothing on screen for up to 15 minutes while the charge IC trickle-feeds current to bring the cell back above the BMS re-entry threshold. If the screen remains black, confirm the charger is delivering at least 5V at 500mA and leave it connected for a full 20 minutes before attempting a power-on.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43404211224666,"sku":"BWCS-KMT400SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43404211257434,"sku":"BWCS-KMT400SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43404211290202,"sku":"BWCS-KMT400SL-3","price":28.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-KMT400SL-1.webp?v=1779369391","url":"https:\/\/batteryweb.com\/products\/kazam-trooper-x40-replacement-battery-37v-1600mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}