{"product_id":"makita-5091d-replacement-battery-12v-3000mah-ni-mh","title":"Makita 5091D 12V Replacement Battery 1200 3000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eMakita 5091D Series — 12V Ni-MH 3000mAh Replacement Battery (192271-4)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 12V Ni-MH 3000mAh replacement battery for the Makita 5091D cordless drill-driver and its variants, including the 5091DWG, 5091DWH, and 5091DZ. It replaces OEM part numbers 1200, 1201, 1201A, 1202, 1202A, 192271-4, 192293-4, 192296-8, and related codes. Capacity is 3000mAh at 36Wh.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003e5091D platform compatibility:\u003c\/strong\u003e\n    The 5091D series shares a common 12V battery form factor and connector across variants. All listed models use the same voltage rail, physical housing dimensions, and terminal layout — the charger handshake works the same across the range without 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 5091D, monitoring the BMS response to motor-start inrush current. The overcurrent threshold handled the spike without tripping, and cell voltage recovery between pulls stayed within spec.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eNi-MH break-in on the 5091D:\u003c\/strong\u003e\n    On first use, run the drill at half load — driving smaller fasteners or drilling pilot holes — for two full discharge-charge cycles before applying maximum torque. This lets the BMS profile the motor inrush draw before locking overcurrent protection thresholds.\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 motor-start inrush during hard drilling\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eWhen you drive large screws or bore into dense hardwood, the 5091D motor pulls a short inrush spike at trigger pull that can exceed the BMS overcurrent threshold — especially on a new or cold pack. The BMS interprets that spike as a fault and cuts the output rail before the motor reaches running speed. This is more common with Ni-MH packs that haven't completed break-in cycles, because the internal resistance is higher and the voltage dip during inrush is sharper. Two half-load cycles stabilise the pack's internal resistance and give the BMS accurate current data to set its threshold correctly.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eDrill bogs under load after partial charges\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eIf the 5091D slows noticeably when driving screws into hardwood or bores through thick material, voltage sag under load is the likely cause. Ni-MH cells that have been repeatedly shallow-cycled — topped up after light use rather than run down properly — develop reduced capacity and higher internal resistance, causing the voltage rail to sag when the motor demands current. Check the pack voltage under no-load first: it should read at or above 13.2V on a full charge. If no-load voltage looks fine but performance still drops under torque, clean the battery terminal contacts on both the pack and the tool with isopropyl alcohol, then run a full discharge-charge cycle before reassessing.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43416083398746,"sku":"BWCS-MKT509PX-1","price":90.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43416083431514,"sku":"BWCS-MKT509PX-2","price":106.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43416083464282,"sku":"BWCS-MKT509PX-3","price":117.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MKT509PX-1.webp?v=1779760240","url":"https:\/\/batteryweb.com\/products\/makita-5091d-replacement-battery-12v-3000mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}