{"product_id":"welch-allyn-thermoscan-pro-4000-replacement-battery-24v-700mah-ni-mh","title":"Welch-Allyn ThermoScan Pro 4000 Replacement Battery 2.4V 700mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eWelch-Allyn ThermoScan Pro 4000 — 2.4V Ni-MH Replacement Battery (53020-0000)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 2.4V 700mAh Ni-MH rechargeable battery for the Welch-Allyn ThermoScan Pro 4000 infrared ear thermometer. It replaces OEM part number 53020-0000 and fits both the ThermoScan Pro 4000 and ThermoScan PRO 4000 variants. Voltage and capacity match the original cell exactly.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eThermoScan Pro 4000 platform fit:\u003c\/strong\u003e\n    Both model variants share the same battery bay, connector orientation, and BMS handshake requirements. The 2.4V rail is fixed by the device's charge IC — swapping to a different voltage trips a hardware fault that won't clear without a full power cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through the ThermoScan Pro 4000's charge-discharge sequence and confirmed the BMS accepted the new cell without fault codes after one complete conditioning cycle. Charge termination triggered correctly at full capacity.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation self-test protocol:\u003c\/strong\u003e\n    After fitting this battery, let the device complete its full power-on self-test without interruption. The ThermoScan Pro 4000 runs a BMS verification routine at startup — cutting power during this sequence registers a false battery fault that persists until the next clean reboot.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eDevice not completing boot sequence after battery swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe ThermoScan Pro 4000 runs a startup verification routine each time power is applied to a new cell. If the battery voltage sits below approximately 2.2V from storage self-discharge, the device may stall mid-boot or show a battery error before the self-test finishes. Place the battery on charge for a full cycle before installing it if it has been sitting unused. A cell at or above 2.35V will clear the boot sequence without issue.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eLow battery alarm triggering immediately after a confirmed full charge\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis is a BMS learn-cycle issue, not a defective cell. The ThermoScan Pro 4000's charge IC calibrates its low-battery threshold against the cell's internal resistance profile, which shifts during the first few charge-discharge cycles on a new Ni-MH cell. A freshly installed battery that hasn't completed one full cycle will read artificially high internal resistance, causing the alarm to trip at a voltage that's actually adequate. Run one complete charge-to-discharge cycle before clinical use to allow the BMS to recalibrate its cutoff threshold.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43381478555738,"sku":"BWCS-BRP400MD-1","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43381478588506,"sku":"BWCS-BRP400MD-2","price":31.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43381478621274,"sku":"BWCS-BRP400MD-3","price":34.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-BRP400MD-1.webp?v=1778901170","url":"https:\/\/batteryweb.com\/products\/welch-allyn-thermoscan-pro-4000-replacement-battery-24v-700mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}