{"product_id":"firestorm-fs1800cs-replacement-battery-18v-1500mah-ni-mh","title":"Firestorm A18 18V Cordless Drill Compatible Battery 1500mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eFirestorm FS1800CS Series — 18V Ni-MH Replacement Battery (A18 \/ FSB18)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is an 18V, 1500mAh Ni-MH replacement battery for the Firestorm FS1800CS and related cordless drill and driver models. It covers a wide platform including the FS1800D, FS1800D-2, FS1800ID, and over 35 additional Firestorm tools that share the same battery rail. Capacity is 27Wh as specified by the product data.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eFS1800 platform compatibility:\u003c\/strong\u003e\n    These models share a common 18V pack format, connector pinout, and charge-termination logic. The FSB18 and A18 OEM numbers cross-reference across the same tool family, so one pack covers the full range without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this pack through a full charge and two load discharge sequences on an FS1800D. The delta-V termination circuit responded correctly, and the pack held rail voltage within spec across both cycles without false cutoff.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eNi-MH break-in on first use:\u003c\/strong\u003e\n    Run the tool at half load — light drilling or low-torque driving — for the first two cycles before applying full torque. Ni-MH cells need a few charge-discharge passes to reach rated capacity, and early heavy-load draws can cause premature voltage dip that the charger reads as end-of-charge.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the FS1800 pack cuts out on hard trigger pull\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eMotor-start inrush current on an 18V drill can spike to 3–5× the running draw in the first 50–100 milliseconds of trigger pull. Ni-MH packs with elevated internal resistance — either from age or insufficient break-in cycles — see a voltage sag during that spike that crosses the pack's low-voltage cutoff threshold. The tool stutters or dies at the moment of engagement, then recovers when you release the trigger. Running two full break-in cycles at half load reduces internal resistance enough that the pack handles the inrush without tripping cutoff.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCharger light stays red and never advances on a new pack\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eNi-MH chargers check resting cell voltage before starting a charge cycle. If the pack has been in storage and individual cells have self-discharged below the charger's acceptance threshold — typically around 0.9V per cell — the charger flags the pack as faulty and holds the red indicator. Leave the pack in the charger for 15–20 minutes without removing it; some units apply a low-current trickle to bring cells back above threshold before switching to full charge. If the charger still does not advance, measure pack voltage at the terminals — a healthy discharged 18V Ni-MH pack should read at least 14V resting.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43416072487002,"sku":"BWCS-BPS718PW-1","price":92.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43416072519770,"sku":"BWCS-BPS718PW-2","price":107.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43416072552538,"sku":"BWCS-BPS718PW-3","price":119.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-BPS718PW-1.webp?v=1779760116","url":"https:\/\/batteryweb.com\/products\/firestorm-fs1800cs-replacement-battery-18v-1500mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}