{"product_id":"fey-elektronik-replacement-battery-37v-3350mah-li-ion","title":"Fey Elektronik PA-UL-LNB19 Compatible Battery 3.7V 3350mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eFey Elektronik PA-UL-LNB19 — 3.7V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V 3350mAh (12.4Wh) Li-ion battery pack built to the Fey Elektronik PA-UL-LNB19 specification. It replaces the original pack in devices that call for this OEM part number. Dimensions are 66.50 × 21.65 × 18.60mm — confirm these against your existing pack before ordering.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePA-UL-LNB19 compatibility:\u003c\/strong\u003e\n    Devices spec'd to this part number operate on a 3.7V nominal rail with a charge ceiling of 4.2V. The replacement pack matches that voltage window and connector footprint, so the host device charge circuit sees no deviation from the original.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this pack through charge and discharge cycles on the bench. The integrated BMS held cutoff at the correct low-voltage threshold and did not trip under normal load profiles. Charge acceptance was consistent across the test units we pulled.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle calibration:\u003c\/strong\u003e\n    Battery packs with an integrated fuel gauge need one full charge-to-discharge cycle after a swap to recalibrate the state-of-charge counter against the new cells. Until that cycle completes, the capacity indicator may read low or erratically — this is expected behaviour, not a fault.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePack not accepted by device after swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eSome devices that use OEM battery packs run a voltage range check or BMS handshake before allowing operation. A freshly shipped pack sits at storage voltage — typically 3.6V or below — and may fall outside the window the device expects on first insertion. The fix is straightforward: connect the pack to a compatible charger before inserting it into the device. Once the pack reaches full charge at 4.2V, the host device's acceptance check passes cleanly.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePack not reaching full charge on the first cycle\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eOn new Li-ion cells, some charge ICs apply a reduced current during the first charge cycle as a conditioning step. This can make the pack appear to stop charging early or show a lower than expected state of charge. It is not a fault with the pack or charger. Run one complete charge cycle through to termination and the charge IC will apply full current on subsequent cycles.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43333498667098,"sku":"BWCS-CM008SL-1","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43333498699866,"sku":"BWCS-CM008SL-2","price":28.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43333498732634,"sku":"BWCS-CM008SL-3","price":31.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-CM008SL-1.webp?v=1778212804","url":"https:\/\/batteryweb.com\/products\/fey-elektronik-replacement-battery-37v-3350mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}