{"product_id":"nidek-keratometer-km500-replacement-battery-6v-2000mah-ni-mh","title":"Nidek KM500 Keratometer Replacement Battery 6V 2000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eNidek KM500 \/ KM-500BPI Keratometer — 6V Ni-MH Replacement Battery (02904)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 6V, 2000mAh Ni-MH replacement battery for the Nidek KM500 and KM-500BPI keratometers. These instruments measure corneal curvature and astigmatism in clinical ophthalmic examinations. The battery supplies the internal power rail during active patient use and standby periods between examinations.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eKM500 and KM-500BPI compatibility:\u003c\/strong\u003e\n    Both models share the same 6V battery bay, connector pinout, and BMS handshake protocol. OEM part numbers 02904, B11304, and KM-500BPI all cross-reference to this cell configuration.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through a full charge-discharge sequence on the KM500 platform. The BMS accepted the cell without fault flags, and the self-test sequence completed normally on the first full charge cycle.\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 without interruption. The KM500 BMS runs a chemistry verification check at startup — cutting power mid-sequence locks in a false battery fault that won't clear 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 KM500 flags a low-battery alarm on a freshly charged replacement\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe KM500 BMS was calibrated to the discharge curve of the original OEM Ni-MH cell. A new replacement cell has a slightly different internal resistance profile until it completes one or two full charge-discharge cycles. The BMS reads this mismatch as a low state-of-charge and triggers the alarm even though the cell is fully charged. Running one complete charge-discharge cycle lets the BMS recalibrate its threshold against the actual cell curve. After that cycle, the alarm clears and the battery indicator reads correctly.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eKM500 not completing boot sequence after battery sat unused in storage\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eNi-MH cells self-discharge at roughly 1–3% per day. A battery stored for several months can drop below the KM500's BMS recovery threshold — typically around 5.4V for a 6V pack — and the device will not boot or will freeze mid-sequence. Connect the battery to the charger for a full uninterrupted charge before attempting to power on the device. If the charge indicator stalls early, leave it on charge — the charge IC applies a slow trickle recovery below a certain voltage before switching to normal charge rate. Once the cell reaches 6.0V the BMS will re-initialise and the boot sequence will complete.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43381435990106,"sku":"BWCS-KRM500MD-1","price":36.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43381436022874,"sku":"BWCS-KRM500MD-2","price":42.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43381436055642,"sku":"BWCS-KRM500MD-3","price":46.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-KRM500MD-1.webp?v=1778900750","url":"https:\/\/batteryweb.com\/products\/nidek-keratometer-km500-replacement-battery-6v-2000mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}