{"product_id":"casio-commando-2-replacement-battery-37v-1800mah-li-ion","title":"Casio BTR811B Commando 2 Replacement Battery 3.7V 1800mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eCasio Commando 2 \/ Commando 4G LTE — 3.7V Li-ion Replacement Battery (BTR811B)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1800mAh Li-ion cell that fits the Casio Commando 2, Commando 4G LTE, C811, and CA201. It replaces OEM parts BTR811B and CA-201L1. Capacity is 6.66Wh — matching the original spec so the fuel gauge IC has a clean reference curve to work from.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCommando 2 and 4G LTE compatibility:\u003c\/strong\u003e\n    Both models share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The 65.53 × 45.10 × 5.40mm cell fits either chassis without modification.\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 Commando 2 platform. The BMS accepted the handshake on first contact, and the charge IC hit a full 4.2V termination voltage without flagging a fault.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard current. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated reference.\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 Commando 2 after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Commando 2 runs a modem that pulls sharp current spikes during signal acquisition. A new cell with a slightly higher internal impedance than the aged original can cause a momentary voltage sag under that load. The fuel gauge IC reads that sag as a low-voltage cutoff event and tells the OS the battery is empty — even though the coulomb counter still shows 25%. One full discharge-charge calibration cycle brings the reported state of charge back in line with actual cell voltage.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePhone reports wrong battery percentage after installing a new cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe fuel gauge IC on the Commando 2 builds its percentage model against the discharge curve of the previous cell. Drop in a new cell and that learned curve is stale — the IC will over- or under-report by 10–20% until it relearns. Drain the battery until the phone shuts itself off, then charge uninterrupted to 100% without disconnecting. After one complete cycle, the coulomb counter resets its reference and percentage accuracy returns to normal.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43404292423770,"sku":"BWCS-CTR811SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43404292456538,"sku":"BWCS-CTR811SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43404292489306,"sku":"BWCS-CTR811SL-3","price":28.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-CTR811SL-1.webp?v=1779369642","url":"https:\/\/batteryweb.com\/products\/casio-commando-2-replacement-battery-37v-1800mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}