{"product_id":"natus-freedop-replacement-battery-12v-230mah-ni-mh","title":"Natus FreeDOP C631 Replacement Battery 12V 230mAh Ni-MH","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eNatus FreeDOP Series — 12V Ni-MH Replacement Battery (C631)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 12V, 230mAh Ni-MH replacement battery for the Natus FreeDOP, DOP CT, and CT+ Doppler handheld stimulator units. The C631 powers the portable neurophysiological monitoring system used during intraoperative neuromonitoring procedures. Voltage and cell chemistry match OEM spec — 12V Ni-MH, 230mAh (2.76Wh).\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eFreeDOP, DOP CT, and CT+ Doppler compatibility:\u003c\/strong\u003e\n    All three models share the same 12V Ni-MH cell requirement, connector pinout, and BMS handshake protocol. The C631 OEM part number spans this platform because the power rail and charge IC are identical across the series.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through full charge and discharge on the FreeDOP platform. The BMS accepted the cell, completed its verification sequence, and reported no faults across repeated cycles.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation self-test protocol:\u003c\/strong\u003e\n    After fitting this battery, allow the device to complete its full power-on self-test cycle without interruption. The FreeDOP's BMS runs a chemistry verification at startup — cutting power during this sequence triggers a false battery fault that persists until the next complete 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 FreeDOP BMS rejects a new C631 cell on first boot\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe FreeDOP's charge IC applies conservative acceptance thresholds calibrated to a conditioned OEM cell. A fresh replacement hasn't completed a full charge-discharge cycle, so its internal resistance profile sits outside the BMS's expected window. This causes the device to flag the battery as non-compliant even when the cell is fully charged. Run one complete charge-discharge cycle before relying on the battery in a clinical setting — this allows the BMS to update its learned baseline for the new cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCharge indicator stalling below 100% on the first charge\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eOn first charge, the FreeDOP's charge IC applies a reduced current ceiling to an unrecognised cell, which causes the charge indicator to plateau short of 100%. This is not a faulty battery — it's the charge controller applying a protective limit until the cell establishes a charge history. Let the first charge run to termination without removing the battery early. By the second full charge cycle, the IC will recognise the cell's delta-V signature and charge to the full 12V endpoint.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43381434122330,"sku":"BWCS-NTC630MD-1","price":38.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43381434155098,"sku":"BWCS-NTC630MD-2","price":44.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43381434187866,"sku":"BWCS-NTC630MD-3","price":48.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-NTC630MD-1.webp?v=1778900787","url":"https:\/\/batteryweb.com\/products\/natus-freedop-replacement-battery-12v-230mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}