{"product_id":"mobistel-cynus-t7-replacement-battery-37v-1800mah-li-polymer","title":"Mobistel Cynus T7 Replacement Battery BTY26186 3.7V 1800mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eMobistel Cynus T7 \/ MT-600S \/ MT-600W — 3.7V Li-Polymer Replacement Battery (BTY26186)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1800mAh lithium-polymer replacement battery for the Mobistel Cynus T7, MT-600S, and MT-600W smartphones. It matches the original BTY26186 cell dimensions at 92.10 × 62.52 × 4.50mm, so it seats correctly in the battery bay without modification. Swap it in when the original cell no longer holds a useful charge.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCynus T7, MT-600S, MT-600W compatibility:\u003c\/strong\u003e\n    All three models share the same 3.7V single-cell architecture, battery connector pinout, and BMS handshake protocol — which is why one cell covers the whole group without adapter or modification.\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 and charge sequence on the MT-600 platform. The BMS accepted the charge curve without fault flags, and the fuel gauge IC began tracking state-of-charge correctly after one complete cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle fuel gauge recalibration:\u003c\/strong\u003e\n    After installation, disable fast charging and run one full discharge down to automatic shutoff, then charge uninterrupted to 100%. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before high-current charging sessions begin.\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 Cynus T7 after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens because the fuel gauge IC is still running the discharge curve it learned from the old, degraded cell. The new cell has a steeper voltage cliff at the lower end of its charge window, and the IC hasn't mapped it yet. When the modem fires a burst transmission or the screen ramps brightness, current draw spikes and the cell voltage drops below the BMS cutoff threshold — even though the reported percentage looks safe. One complete discharge-charge cycle without interruption resets the coulomb counter and eliminates these shutdowns.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePhone reports incorrect battery percentage after replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Cynus T7's fuel gauge IC stores calibration data tied to the previous cell's internal resistance and capacity fade profile. A fresh 1800mAh cell has different impedance characteristics, so the IC's percentage readings drift — often showing 100% that drops sharply to 60% within minutes, or freezing near 20% before cutting out. Force a full calibration cycle: drain the phone to automatic shutdown, then charge to 100% on a standard 5V charge with fast charging off. After that single cycle, percentage reporting stabilises against the new cell's actual discharge curve.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43404283445338,"sku":"BWCS-MCT700SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43404283478106,"sku":"BWCS-MCT700SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43404283510874,"sku":"BWCS-MCT700SL-3","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MCT700SL-1.webp?v=1779369616","url":"https:\/\/batteryweb.com\/products\/mobistel-cynus-t7-replacement-battery-37v-1800mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}