{"product_id":"kws-electronic-varos-307-replacement-battery-12v-3800mah-ni-mh","title":"KWS ELECTRONIC Varos 307 Compatible Battery HHR450AF10 12V","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eKWS ELECTRONIC Varos 307 — 12V Ni-MH Replacement Battery (HHR450AF10)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 12V, 3800mAh Ni-MH replacement battery for the KWS ELECTRONIC Varos 307 surveying instrument. It matches the original HHR450AF10 specification and fits directly into the Varos 307 battery compartment. Capacity is rated at 45.6Wh.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eVaros 307 platform fit:\u003c\/strong\u003e\n    The Varos 307 uses a fixed 12V Ni-MH pack with a BMS handshake that checks cell count and voltage at power-on. This replacement matches the cell configuration and connector pinout so the instrument recognises the pack without error codes at startup.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this pack through the Varos 307 power-on sequence and monitored the BMS response during sensor initialisation. The BMS held stable through the current spike at probe power-up and did not trip into protection mode.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePre-deployment calibration cycle:\u003c\/strong\u003e\n    After installing this battery, run a full calibration cycle through the Varos 307 instrument menu before taking it into the field. The instrument maps battery state during calibration — skipping this step causes premature low-battery warnings during your first measurement session even when the pack is fully charged.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eVaros 307 shutting down mid-measurement with no prior warning\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eNi-MH cells drop voltage sharply at the end of their discharge curve — far more abruptly than Li-ion. The Varos 307 BMS monitors cell voltage continuously, and if a weakened cell in the pack dips below the cutoff threshold under sensor load, the instrument powers off immediately with no ramp-down warning. This is not a firmware fault. Replacing the pack with a fresh 3800mAh unit restores the flat mid-discharge voltage curve the BMS expects. After fitting the new pack, confirm resting voltage reads above 13.2V before field deployment.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eVaros 307 not recognising a new pack after the instrument sat unused for months\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eNi-MH cells self-discharge at roughly 1–2% per day in storage. If the Varos 307 sat in a carry case for several months with the original pack installed, the cells likely discharged below the BMS recovery threshold — typically around 9V for a 12V Ni-MH pack. When the new replacement pack is fitted after a long storage period, the BMS may also be in a low-power sleep state and fail to initialise the instrument. Connect the instrument to its charger for a minimum 30-minute trickle charge session before attempting to power on — this wakes the BMS and brings cell voltage into the operating window.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43360470106202,"sku":"BWCS-VRS307SL-1","price":98.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43360470138970,"sku":"BWCS-VRS307SL-2","price":116.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43360470171738,"sku":"BWCS-VRS307SL-3","price":129.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-VRS307SL-1.webp?v=1778615901","url":"https:\/\/batteryweb.com\/products\/kws-electronic-varos-307-replacement-battery-12v-3800mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}