{"product_id":"cefar-myo-4-replacement-battery-72v-2000mah-ni-mh","title":"Cefar Myo 4 Replacement Battery 7.2V 2000mAh Ni-MH","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eCefar Myo 4 \/ Activ 4 \/ Rehab 4 Pro — 7.2V Ni-MH Replacement Battery (2651)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 7.2V 2000mAh Ni-MH battery replaces the original cell in the Cefar Myo 4, Activ 4, Rehab 4 Pro, and Bodymax Trainer (NGSF4) electrotherapy units. All four devices share the same battery bay, connector, and BMS handshake protocol. Capacity matches the OEM specification — 14.4Wh.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eShared platform — Myo 4, Activ 4, Rehab 4 Pro, Bodymax Trainer:\u003c\/strong\u003e\n    These units run the same 7.2V power architecture, identical connector pinout, and the same BMS communication logic. One cell fits all four 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 charge, load, and self-test sequences on the Cefar platform. The BMS accepted the new cell without faulting, completed its chemistry verification pass, and held voltage within spec under simulated stimulation load.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePower-on self-test — do not interrupt:\u003c\/strong\u003e\n    After inserting this battery, let the device complete its full startup sequence before beginning any session. The Cefar BMS runs a cell-verification check at boot. Interrupting it locks in a false battery fault that won't clear until the next full cold reboot.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eLow battery alarm on the Cefar Myo 4 immediately after a confirmed full charge\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Myo 4's BMS stores a chemistry profile calibrated against the OEM cell's internal resistance curve. A new replacement cell has a slightly different resistance signature until it beds in over the first few cycles. The BMS reads this as a weaker cell than expected and triggers the low-battery threshold early. Run one complete charge-discharge cycle before clinical use — after that, the BMS recalibrates its reference point and the alarm clears. If the alarm persists past cycle three, check resting voltage with a multimeter: a healthy charged cell should read 8.4–8.6V.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCefar device won't power on after the replacement battery sat in storage\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eNi-MH cells self-discharge at roughly 1–2% per day in storage. If this battery shipped or sat unused for several weeks, its resting voltage may have dropped below the Cefar BMS recovery threshold — typically around 5.4V for a 7.2V pack. The BMS interprets this as a damaged or absent cell and refuses to boot. Connect the charger and leave it for a minimum of four hours before attempting power-on; the charge IC will trickle-charge the pack back above the recovery floor before switching to full current. Do not attempt to force a boot during this phase.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43381477376090,"sku":"BWCS-CFA410MD-1","price":37.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43381477408858,"sku":"BWCS-CFA410MD-2","price":43.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43381477441626,"sku":"BWCS-CFA410MD-3","price":47.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-CFA410MD-1.webp?v=1778901051","url":"https:\/\/batteryweb.com\/products\/cefar-myo-4-replacement-battery-72v-2000mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}