{"product_id":"honeywell-bw-max-xt-ii-replacement-battery-37v-3000mah-li-polymer","title":"Honeywell XT-BAT-K1 BW Max XT II Replacement Battery 3.7V 3000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eHoneywell BW Max XT II — 3.7V Li-Polymer Replacement Battery (XT-BAT-K1)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V, 3000mAh lithium-polymer battery replaces the OEM pack in the Honeywell BW Max XT II and BW GasAlert Max XT II portable multi-gas detectors. It also fits the GasAlert Max XT Legacy Multigas Monitor and the Max XT II multi-gas detector series. Part number XT-BAT-K1 matches the original connector, BMS handshake, and housing dimensions exactly.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eBW Max XT II platform fit:\u003c\/strong\u003e\n    All listed Max XT II variants share the same 3.7V power rail, the same polarised connector, and the same BMS communication protocol. The detector's firmware validates the pack at startup — this battery passes that check on the BW Max XT II and BW GasAlert Max XT II without triggering a battery fault flag.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this pack on a BW Max XT II unit and logged the BMS response across the sensor initialisation spike and sustained four-sensor load. The protection circuit held within spec at both draw peaks, and the pack completed a full charge cycle without thermal trip.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install calibration requirement:\u003c\/strong\u003e\n    After fitting this battery, run a full sensor calibration cycle through the instrument menu before field deployment. The Max XT II maps battery state during calibration — skipping this step causes the detector to display premature low-battery warnings on the first monitoring session.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBMS lockout on the Max XT II after the pack sat unused for months\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eLithium-polymer cells in low-draw instruments self-discharge slowly over storage. If the BW Max XT II sat unused long enough, the cell voltage can drop below 3.0V — the threshold where the BMS locks out to prevent cell damage. At that point the detector shows no signs of life and the charger may not initiate a charge cycle at all. Connecting the unit to the OEM charger for 15–20 minutes without interruption usually wakes the BMS via a trickle pre-charge mode. If the pack recovers, the open-circuit voltage should read above 3.4V before the main charge cycle kicks in.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eMax XT II shuts down mid-survey with no prior low-battery warning\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the pack's resting voltage reads acceptable but sags sharply under the combined draw of all four sensors running simultaneously. The BMS interprets the voltage sag as a critically low cell and triggers a protection cutoff — the detector shuts off without cycling through the normal low-battery alarm sequence. An aged or partially depleted cell causes this even when the on-screen indicator shows 30–40% remaining. Charge the pack to full, allow it to rest for ten minutes, then check that the open-circuit voltage holds above 3.7V before redeploying.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43360480723034,"sku":"BWCS-HNY100SL-1","price":29.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43360480755802,"sku":"BWCS-HNY100SL-2","price":33.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43360480788570,"sku":"BWCS-HNY100SL-3","price":36.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-HNY100SL-1.webp?v=1778615883","url":"https:\/\/batteryweb.com\/products\/honeywell-bw-max-xt-ii-replacement-battery-37v-3000mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}