{"product_id":"simolio-big-over-ear-wireless-tv-headset-sm-825d-pro-replacement-battery-37v-600mah-li-polymer","title":"Simolio SM-825D Pro Wireless Headset Compatible Battery 3.7V 600mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSimolio SM-825D Pro Series — 3.7V Li-Polymer Replacement Battery (SM-003-BAT)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 600mAh lithium-polymer cell that replaces the original battery in the Simolio BIG OVER EAR wireless TV headset SM-825D Pro. It also fits the SM-829D1 and SM-829D2. Dimensions are 44.60 × 27.30 × 6.80mm — match these before fitting if you are unsure which revision of the headset you have.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSM-825D Pro and SM-829 series fit:\u003c\/strong\u003e\n    These models share the same cell format, voltage rail, and connector footprint. The BMS in each headset expects a 3.7V nominal Li-Polymer pack — swapping outside that spec triggers a protection cutoff at the charging IC.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through the SM-825D Pro base station and confirmed the BMS completed its handshake, accepted charge current, and released to the headset without a fault flag.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle base station protocol:\u003c\/strong\u003e\n    Seat the headset in the base station immediately after fitting and leave it there for a complete charge cycle before use. The SM-825D Pro base needs to log the new cell before its talk-time counter reads accurately — skipping this step causes the indicator to misreport charge state.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBase station not recognising the new pack after fitting\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe SM-825D Pro base station communicates with the headset's BMS before it commits charge current. If the replacement cell arrives at storage voltage — typically around 3.6V — the base may show no charge activity or flash an error LED. This is a BMS initialisation issue, not a faulty battery. Place the headset in the cradle and leave it undisturbed for at least 90 minutes; the charging IC will trickle-charge the cell up to the threshold where the BMS handshake completes and normal charge current begins.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eHeadset cuts out mid-audio even with a charged cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe SM-825D Pro draws on two loads simultaneously — the audio driver and the wireless radio. Under combined draw, a degraded or under-conditioned cell can sag below the BMS cutoff threshold momentarily, dropping audio mid-stream. This is distinct from short talk time and happens even when the indicator shows partial charge. Run three to five full charge-and-use cycles to let the cell reach its rated capacity; voltage sag under dual load reduces noticeably after the third cycle. If cut-outs persist after five cycles, check that the cell is seated flat — any pressure on the connector pin raises contact resistance and amplifies voltage sag.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43428101292122,"sku":"BWCS-SML825SL-1","price":38.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43428101324890,"sku":"BWCS-SML825SL-2","price":45.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43428101357658,"sku":"BWCS-SML825SL-3","price":49.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SML825SL-1.webp?v=1779934133","url":"https:\/\/batteryweb.com\/products\/simolio-big-over-ear-wireless-tv-headset-sm-825d-pro-replacement-battery-37v-600mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}