{"product_id":"video-devices-sound-devices-633-mixer-replacement-battery-74v-10400mah-li-ion","title":"Video Devices XL-B3 7.4V Replacement Battery for Sound Devices 633","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eVideo Devices Sound Devices 633 \/ PIX-E Series — 7.4V Li-ion Replacement Battery (XL-B3)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 7.4V, 10400mAh (76.96Wh) lithium-ion battery replaces the XL-B3 cell used in the Sound Devices 633 field mixer, PIX 240i, PIX-E, and 4K recording monitors. These are professional portable audio and video recording devices used on location film and television sets. One cell covers all listed models — same voltage rail, same connector, same BMS handshake requirements.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003e633, PIX 240i, PIX-E, and 4K monitor compatibility:\u003c\/strong\u003e\n    All four platforms share the XL-B3 form factor and operate on the same 7.4V nominal rail. The connector pinout and BMS communication protocol are identical across the lineup, so one replacement covers the entire group 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 633 and PIX-E under full operational load — audio mixing, timecode, and monitor output running simultaneously. The BMS held stable charge acceptance and cut off cleanly at the low-voltage threshold without triggering false shutdowns.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle BMS initialisation on the 633:\u003c\/strong\u003e\n    Run the first charge through the mixer body or OEM charger, not a generic Li-ion charger. The 633's BMS maps its battery-remaining display to the cell's discharge curve during that initial cycle — skipping this step causes the percentage indicator to read inaccurately for the life of the cell.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the PIX-E monitor cuts output when audio and video load run together\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe PIX-E draws from a single cell powering the display, recording engine, and any connected audio simultaneously. At peak load — 4K capture plus active audio monitoring — instantaneous current demand spikes beyond what a degraded or partially charged cell can sustain. The BMS interprets the voltage sag as a low-battery condition and throttles or cuts output to protect the cell. A fully charged replacement cell at 8.4V (full charge ceiling) handles these spikes without triggering the cutoff.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBattery percentage jumping erratically on the 633 display\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe 633 maps its fuel gauge to a specific voltage-to-capacity curve calibrated during the first charge cycle. A new cell with a slightly different discharge curve will cause the indicator to jump — dropping from 60% to 30% suddenly, then stabilising. This is a calibration mismatch, not a cell fault. Fully discharge the battery through normal operation, then charge it completely in the 633 body. After one full cycle, the BMS recalibrates to the new cell's curve and the percentage display stabilises.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43333599723610,"sku":"BWCS-NF980MU-1","price":116.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43333599756378,"sku":"BWCS-NF980MU-2","price":133.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43333599789146,"sku":"BWCS-NF980MU-3","price":146.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-NF980MU-1.webp?v=1778212993","url":"https:\/\/batteryweb.com\/products\/video-devices-sound-devices-633-mixer-replacement-battery-74v-10400mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}