{"product_id":"carewell-cpm-8000-replacement-battery-74v-4000mah-li-polymer","title":"Carewell CPM-8000 Replacement Battery 7.4V 4000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eCarewell CPM-8000 — 7.4V Li-Polymer Replacement Battery (AHB855183)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 7.4V 4000mAh Li-Polymer battery replaces the OEM AHB855183 cell in the Carewell CPM-8000 continuous passive motion machine. The CPM-8000 is a motorized rehabilitation device used post-surgery to move joints passively through a controlled range of motion. When the original battery degrades and the unit loses portability, this replacement restores cordless operation for patient recovery sessions.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCPM-8000 platform fit:\u003c\/strong\u003e\n    The AHB855183 cell uses a specific connector pinout and BMS communication protocol tied to the CPM-8000 controller board. The voltage rail and cell geometry — 74.50 × 52.40 × 15.30mm — match the OEM bay exactly, so no adapter or modification is required.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this battery through the CPM-8000 power-on sequence and confirmed the BMS handshake completed without fault codes. Load cycling through the motor drive confirmed stable voltage delivery across the full operating range.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation self-test protocol:\u003c\/strong\u003e\n    After fitting this battery, allow the CPM-8000 to complete its full power-on self-test without interruption. The device runs a BMS verification at startup — cutting power during this sequence triggers a false battery fault that persists until the next clean reboot.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCPM-8000 shutting off mid-session in the first ten uses\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eNew Li-Polymer cells have a higher internal resistance before the electrode structure fully forms. The CPM-8000 motor controller pulls a sharp current spike at the start of each motion cycle, and a new cell's internal resistance causes a brief voltage sag under that load. The BMS reads this sag as a low-cell-voltage condition and trips the output. This behaviour typically resolves after 8–10 full charge-discharge cycles as the cell's internal resistance drops to its rated value.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCPM-8000 will not power on after the battery sat unused\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-Polymer cells self-discharge at roughly 1–3% per month in storage. If the cell dropped below approximately 2.5V per cell (5.0V pack total), the BMS enters deep-discharge lockout to protect the chemistry and the device will show no response at all. To recover, connect the charger and leave it for a minimum of 30–60 minutes without attempting to power on — the charge IC applies a low-current pre-charge trickle below 3.0V per cell to bring the pack back above the BMS re-enable threshold before switching to standard CC\/CV charge.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43381357805658,"sku":"BWCS-CMS650MD-1","price":49.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43381357838426,"sku":"BWCS-CMS650MD-2","price":58.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43381357871194,"sku":"BWCS-CMS650MD-3","price":64.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-CMS650MD-1.webp?v=1778900175","url":"https:\/\/batteryweb.com\/products\/carewell-cpm-8000-replacement-battery-74v-4000mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}