{"product_id":"suzuken-kenz-ecg-305-replacement-battery-12v-2000mah-ni-mh","title":"Suzuken Kenz ECG 305 Replacement Battery 12V 2000mAh Ni-MH","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSuzuken Kenz ECG 305 — 12V Ni-MH 2000mAh Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 12V, 2000mAh Ni-MH replacement battery for the Suzuken Kenz ECG 305 portable electrocardiogram. It fits both the ECG 305 and ECG-305 model designations — same unit, same battery slot. Capacity is 24Wh, matching the original cell specification.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eKenz ECG 305 compatibility:\u003c\/strong\u003e\n    The ECG 305 uses a 12V Ni-MH pack with a fixed connector and BMS handshake tied to that chemistry. Swapping to a different chemistry or voltage causes the device to reject the pack at the power-on self-test stage.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran the battery through the ECG 305 startup sequence and confirmed the BMS accepted the cell, completed its verification cycle, and held charge without triggering a low-battery interrupt under normal diagnostic load.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation self-test protocol:\u003c\/strong\u003e\n    After fitting this battery, let the ECG 305 complete its full power-on self-test without interruption. The device runs a BMS verification pass at startup — cutting power mid-sequence logs a false battery fault that clears only on the next complete reboot cycle.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Kenz ECG 305 rejects a new battery at first boot\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe ECG 305 BMS checks the incoming cell against a stored threshold calibrated to a fully conditioned Ni-MH pack. A new, uncycled cell sits slightly below that threshold voltage even after a full charge. The device reads this as a fault and flags the battery before the self-test passes. Running one complete charge-discharge cycle brings the cell into the BMS acceptance window. After that first cycle, the device boots and verifies normally.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCharge indicator stalls below 100% on the first charge\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens because the ECG 305 charge IC applies a conservative current limit when it cannot confirm the cell's history. On a new Ni-MH cell, the IC holds at a reduced rate and may not reach the 100% indicator on the first pass. This is a charge-controller behaviour, not a defective cell. Run a full discharge under device load, then recharge — on the second cycle the charge IC adjusts its limit and the indicator reaches full.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43381481111642,"sku":"BWCS-KZC601MD-1","price":51.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43381481144410,"sku":"BWCS-KZC601MD-2","price":60.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43381481177178,"sku":"BWCS-KZC601MD-3","price":67.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-KZC601MD-1.webp?v=1778901194","url":"https:\/\/batteryweb.com\/products\/suzuken-kenz-ecg-305-replacement-battery-12v-2000mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}