{"product_id":"plantronics-savi-replacement-battery-37v-140mah-li-polymer","title":"Plantronics Savi 84598-01 Replacement Battery 3.7V 140mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003ePlantronics Savi W440 Series — 3.7V Li-Polymer Replacement Battery (84598-01)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V, 140mAh Li-Polymer battery replaces part number 84598-01 in the Plantronics Savi wireless DECT headset series. It fits the Savi WH500, Savi W440, and Savi W440-M among others. Swap it when the original cell no longer holds enough charge to complete a standard call session.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSavi W440 and WH500 platform fit:\u003c\/strong\u003e\n    These headsets share the same compact housing, 3.7V power rail, and BMS handshake protocol with the base station. One cell spec covers the full range because the charging circuit and connector are identical across the group.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through the Savi base station and confirmed the BMS handshake completed correctly. The base station registered the pack, accepted a full charge, and the headset powered on without an error state.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst charge in the base station:\u003c\/strong\u003e\n    Dock the headset in the base station and leave it through a complete charge cycle before taking a call. DECT headsets log the new cell during this cycle — until that log completes, the talk-time indicator on the base will not read accurately.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Savi W440 cuts out mid-call even with a charged battery\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe W440 drives both audio processing and a DECT radio transmitter from the same 140mAh cell. Under combined load, a degraded or storage-voltage cell can sag below the BMS cutoff threshold even when the base indicator shows a full charge. The BMS trips to protect the cell, and the headset drops the call without warning. A fresh cell at rated capacity handles the combined draw without hitting that floor.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBase station shows full charge but headset goes dead after a short call\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the replacement cell arrives at storage voltage — typically around 3.6V — and the first charge cycle was too short to bring it to full capacity. The base station light turns green based on charge current dropping off, not actual cell state-of-charge, so it can show full before the cell is truly topped up. Leave the headset docked undisturbed for a complete cycle of at least two hours. After that cycle, the cell should reach 4.2V and talk time will reflect the rated 140mAh capacity.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43428151885914,"sku":"BWCS-PLW440SL-1","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43428151918682,"sku":"BWCS-PLW440SL-2","price":29.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43428151951450,"sku":"BWCS-PLW440SL-3","price":32.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-PLW440SL-1.webp?v=1779934245","url":"https:\/\/batteryweb.com\/products\/plantronics-savi-replacement-battery-37v-140mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}