{"product_id":"fujikura-fsm-50s-replacement-battery-132v-3500mah-ni-mh","title":"Fujikura FSM-50S Replacement Battery 13.2V 3500mAh Ni-MH","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eFujikura FSM-50S \/ FSM-60S Series — 13.2V Ni-MH Replacement Battery (11HR-4\/3FAU)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 13.2V, 3500mAh Ni-MH replacement battery for the Fujikura FSM-50S, FSM-50R, FSM-60S, and FSM-60R fusion splicers. It replaces OEM part numbers including 11HR-4\/3FAU, BTR-08, BTR-06L, and BTR-06S. The FSM-50S and FSM-60S are precision optical fiber fusion splicers used in telecommunications and fiber network installation.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eFSM-50 and FSM-60 platform compatibility:\u003c\/strong\u003e\n    The FSM-50 and FSM-60 series share the same 13.2V battery bay, connector pinout, and BMS handshake protocol. One battery format covers both R and S variants across both model lines.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this battery through charge and discharge on the FSM-60S bench unit. The BMS accepted the cell chemistry without fault codes, and the splicer completed its arc calibration sequence without interruption on the first cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFusion splicer startup sequence:\u003c\/strong\u003e\n    After installing a new battery, let the FSM-50S complete its full power-on self-test without pulling the battery or pressing any function keys. The splicer runs a BMS verification step at startup, and cutting power mid-sequence causes a latched battery fault that clears only on the next clean reboot.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the FSM-50S reports a battery fault after a fresh charge\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe FSM-50S BMS uses a learned capacity threshold calibrated to the original OEM cell. A new replacement cell has not yet passed the BMS learn cycle, so the splicer may flag a battery warning even after a confirmed full charge. This is not a cell defect. Run one complete charge-discharge cycle — power the splicer on, let it operate until it prompts for charge, then charge fully — and the BMS resets its threshold to match the new cell. After that first cycle, the fault clears and does not return.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCharge indicator stuck below 100% on the first charge\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eOn first charge, the FSM-50S charge IC applies a conservative current limit when it cannot confirm the cell's internal resistance profile. This causes the indicator to plateau at 90–95% and stall. Remove the battery, wait 60 seconds, reinsert it, and start a fresh charge cycle. The charge IC reinitialises its algorithm and typically reaches 100% within the second charge session. Target a resting voltage of 13.2V measured at the battery terminals before treating the first charge as complete.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43381498642522,"sku":"BWCS-FRK500MD-1","price":89.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43381498675290,"sku":"BWCS-FRK500MD-2","price":104.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43381498708058,"sku":"BWCS-FRK500MD-3","price":115.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-FRK500MD-1.webp?v=1778901265","url":"https:\/\/batteryweb.com\/products\/fujikura-fsm-50s-replacement-battery-132v-3500mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}