{"product_id":"firestorm-fs1200d-replacement-battery-12v-2000mah-ni-mh","title":"Firestorm FS120B 12V Ni-MH Replacement Battery 2000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eFirestorm FS1200D Series — 12V Ni-MH Replacement Battery (FS120B)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 12V 2000mAh Ni-MH replacement battery pack for the Firestorm FS1200D and FS1200D-2 cordless drill\/driver, along with over 35 compatible models including the FS1202BN and FS1202D. It replaces OEM parts FS120B, FSB12, and HPB12, among others. Capacity is rated at 2000mAh (24Wh) — matching the original pack specification.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eFS1200D series compatibility:\u003c\/strong\u003e\n    These drills share the same 12V battery rail, connector footprint, and BMS handshake protocol across the FS1200D, FS1200D-2, FS1202BN, and FS1202D platforms — one pack fits all without adapter or modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this pack through repeated trigger-pull cycles on a loaded FS1200D driver. The BMS handled motor-start inrush without tripping, and cell voltages stayed balanced across the discharge curve through sustained fastening sequences.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBreak-in procedure for motor-start protection:\u003c\/strong\u003e\n    On first use, run the drill at half load for two cycles before full-torque applications. This lets the BMS profile the motor inrush current draw and set accurate overcurrent thresholds — skipping this step can cause premature BMS trips on hard starts.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBMS cutoff on FS1200D motor-start inrush surge\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eNi-MH packs in 12V drill platforms are susceptible to BMS overcurrent trips when the motor draws its start-up inrush spike — typically 3–5× the rated running current. A freshly charged or freshly installed pack has not yet logged a motor inrush profile, so the BMS protection threshold defaults conservatively low. This causes the tool to cut out instantly on the first hard trigger pull. Two half-load conditioning cycles teach the BMS the actual inrush signature, after which it sets a threshold that clears the spike without nuisance tripping.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eDrill bogs under load even with a full charge indicator\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA drill that shows full charge but loses torque or slows under load is showing voltage sag — the cell pack can't sustain voltage under current draw. On Ni-MH packs, this is usually caused by elevated internal resistance from either age-related capacity fade or repeated shallow cycling that never fully discharged the cells. Check the rail contacts on both the pack and the tool — corrosion or debris adds resistance that amplifies sag. Clean contacts with a dry brush, then run a full discharge-to-cutoff cycle followed by a complete recharge to allow the BMS to recalibrate the state-of-charge curve.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43416073175130,"sku":"BWCS-BPS712PX-1","price":75.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43416073207898,"sku":"BWCS-BPS712PX-2","price":88.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43416073240666,"sku":"BWCS-BPS712PX-3","price":97.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-BPS712PX-1.webp?v=1779760116","url":"https:\/\/batteryweb.com\/products\/firestorm-fs1200d-replacement-battery-12v-2000mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}