{"product_id":"ryobi-cth1802-replacement-battery-18v-3300mah-ni-mh","title":"Ryobi 18V Hedge Trimmer Replacement Battery 3300mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eRyobi CTH1802 Series — 18V Ni-MH Replacement Battery (B-8288)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is an 18V 3300mAh Ni-MH replacement battery for the Ryobi CTH1802 cordless hedge trimmer and related 18V Ryobi tools. It fits the CTH1802, CTH1802K, HD1800M, HP1802M, and 17 additional models sharing the same 18V Ni-MH platform. Dimensions are 132.95 x 73.00 x 104.90mm — check your housing clearance before ordering.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCTH1802 platform compatibility:\u003c\/strong\u003e\n    The CTH1802 series and its sibling models share the same 18V Ni-MH voltage rail and battery connector footprint. OEM part numbers B-8288, BCHI-18, BPT1027, 130224007, and 130256001 all map to this same pack — Ryobi used multiple part numbers across production runs, but the cell format and BMS handshake remain consistent across the platform.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this pack through full charge and load discharge sequences on an 18V Ni-MH compatible charger. The BMS held steady through the dual-action blade motor's start inrush current without tripping overcurrent protection. Cell temperature stabilised within the expected range under sustained trimming load.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst two cycles on the CTH1802:\u003c\/strong\u003e\n    Run the trimmer at partial blade load — light hedge passes, not dense branch work — for the first two charge cycles. This lets the BMS log the motor's actual inrush draw before it locks overcurrent protection thresholds. Skipping this on Ni-MH packs can cause premature BMS cutoff during the first heavy trimming session.\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 CTH1802 motor-start inrush surge\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe CTH1802's dual-action blade motor draws a sharp current spike the instant the trigger is pulled. On a fresh or storage-rested Ni-MH pack, the BMS may read this spike as an overcurrent event and cut power before the blades reach speed. This is not a faulty battery — it is the BMS protecting cells that have not yet been profiled under load. Two partial-load break-in cycles give the BMS enough data to distinguish a normal motor-start surge from a genuine fault. After break-in, trigger-pull cutoffs on this pack stop occurring under normal trimming conditions.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCTH1802 runs weak and bogs mid-cut\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eBogging under load on the CTH1802 is almost always voltage sag — the battery's output voltage drops under sustained blade load rather than holding steady. On Ni-MH chemistry, this gets worse when the rail contacts in the tool's battery slot have oxidation or debris build-up, because added contact resistance compounds the sag. Clean the battery terminals and the tool's contact rails with isopropyl alcohol before dismissing a weak-running pack as a capacity problem. If the pack reads below 15.5V under load on a multimeter, the cells are genuinely fatigued and the pack needs replacement.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43416066228314,"sku":"BWCS-RTB180PX-1","price":115.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43416066261082,"sku":"BWCS-RTB180PX-2","price":136.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43416066293850,"sku":"BWCS-RTB180PX-3","price":151.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-RTB180PX-1.webp?v=1779760056","url":"https:\/\/batteryweb.com\/products\/ryobi-cth1802-replacement-battery-18v-3300mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}