{"product_id":"airis-n509-replacement-battery-37v-1300mah-li-ion","title":"Airis N509 Replacement Battery 3.7V 1300mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAiris N509 \/ T605 — 3.7V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V 1300mAh Li-ion cell restores power to the Airis N509 and T605 handheld PDAs. These mid-2000s pocket PCs rely on a single-cell Li-ion pack to run applications, hold contacts, and keep RAM-resident data alive between sessions. Capacity figures are taken directly from the product specification — 4.81Wh total energy.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eN509 and T605 shared platform:\u003c\/strong\u003e\n    Both handhelds draw from the same 3.7V single-cell architecture and use the same physical footprint — 50.00 × 35.90 × 8.50mm. The BMS threshold and connector pinout match across both models, so one cell covers either unit without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled the cell through charge and discharge on the bench and confirmed the protection circuit trips correctly at undervoltage. The BMS re-engaged cleanly on reconnect without requiring an external reset.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eRAM power before removal:\u003c\/strong\u003e\n    Sync all open data to the host PC before pulling the old battery. The N509 stores active application state and unsaved contacts in SRAM powered directly by the main cell — a full power removal without syncing first will erase that data permanently.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the N509 loses data after a battery swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe N509 uses SRAM for active storage — no flash buffer holds open application data between power cycles. The moment the battery voltage drops to zero, that memory clears. A backup battery or capacitor on these older PDAs is either absent or too small to hold state through a full swap. The only reliable fix is a full ActiveSync or WMDC sync to the host machine before removing the cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eN509 stuck on blank screen after new battery install\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA freshly shipped Li-ion cell may sit at 3.0V or below after storage — below the N509's minimum boot threshold. The device will not complete its boot sequence at that voltage and shows a blank or unresponsive screen. Connect to the OEM charger and let the cell reach at least 3.6V before attempting to power on. Once charging is confirmed by the charge LED, a full charge cycle before first boot prevents a repeat of the same symptom.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43415948132442,"sku":"BWCS-MIO168SL-1","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43415948165210,"sku":"BWCS-MIO168SL-2","price":30.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43415948197978,"sku":"BWCS-MIO168SL-3","price":33.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MIO168SL-1.webp?v=1779758396","url":"https:\/\/batteryweb.com\/products\/airis-n509-replacement-battery-37v-1300mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}