{"product_id":"infinite-prime-wes-siren-replacement-battery-72v-700mah-ni-mh","title":"Infinite Prime WES Siren 7.2V Replacement Battery OS826","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eInfinite Prime WES Siren — 7.2V Ni-MH Replacement Battery (OS826)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 7.2V, 700mAh Ni-MH cell replaces the backup battery in the Infinite Prime WES Siren unit. The WES Siren is a wireless external sounder used in residential and commercial intruder alarm systems. When the original cell degrades, the siren loses the ability to trigger audible alerts during a mains failure or alarm event.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePrime WES Siren fit:\u003c\/strong\u003e\n    The WES sounder uses a dedicated battery bay sized for this cell — 44.50 × 31.00 × 20.90mm. The connector and voltage rail match the original OS826 specification, so the siren's internal charge circuit accepts the cell without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through the WES siren charge circuit and confirmed the BMS accepted the new cell within normal float parameters. Charge acceptance was stable and the over-voltage cutoff triggered correctly at the top of the charge window.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install charge window:\u003c\/strong\u003e\n    Do not run a zone or sounder test immediately after fitting this cell. Allow 24–48 hours on float charge first. The siren's charge circuit needs that window to bring the Ni-MH cell up to full capacity — triggering a test before that point can cause a false low-battery report on the panel.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the WES Siren stays silent on test after a battery swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Prime WES Siren applies a short delay — typically 30 to 60 seconds — before the sounder activates on a fresh cell. This is a charge-stabilisation window built into the siren firmware, not a fault. If the panel sends a test trigger during this window, the sounder will not respond. Wait at least one minute after closing the siren cover before initiating any walk test or sounder check.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePanel reports low battery fault 24 hours after fitting new cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eNi-MH cells fresh out of packaging often carry a partial charge — typically 30–50% of rated capacity. The alarm panel reads voltage, not charge percentage, and a partially charged Ni-MH cell at rest can sit below the panel's low-battery threshold. The cell needs a full 24–48 hour float charge cycle via the siren's own charge circuit before the panel recognises it as healthy. If the fault clears after 48 hours, the cell and circuit are functioning correctly — no further action needed.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43309831684186,"sku":"BWCS-MOS826BT-1","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43309831716954,"sku":"BWCS-MOS826BT-2","price":31.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43309831749722,"sku":"BWCS-MOS826BT-3","price":34.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MOS826BT-1.webp?v=1777868261","url":"https:\/\/batteryweb.com\/products\/infinite-prime-wes-siren-replacement-battery-72v-700mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}