{"product_id":"vivitar-dvr-850w-replacement-battery-37v-750mah-li-ion","title":"Vivitar BLI-885 DVR-850W Replacement Battery 3.7V 750mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eVivitar DVR-850W \/ ViviCam 8027 — 3.7V Li-ion Replacement Battery (BLI-885)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 750mAh Li-ion cell that replaces the BLI-885 in the Vivitar DVR-850W, DVR850W, V8027, and ViviCam 8027 compact camcorders. It fits the same slot as the original and connects through the same 3-pin interface. Capacity comes straight from the product data: 750mAh \/ 2.78Wh.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eDVR-850W and ViviCam 8027 compatibility:\u003c\/strong\u003e\n    Both models draw from the same 3.7V rail and use identical connector pinouts and BMS handshake protocols — one cell covers the full 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 charge and full discharge on DVR-850W hardware. The BMS accepted the charge current without cutoff, and the protection circuit tripped correctly at the low-voltage threshold.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first install:\u003c\/strong\u003e\n    After fitting this cell, run one complete discharge to auto-shutoff, then charge uninterrupted to 100% before recording. The camcorder's fuel gauge IC is calibrated to the old cell's discharge curve — one full cycle resets it to the new cell's profile.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the DVR-850W shows wrong battery percentage after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe DVR-850W tracks charge state using a coulomb counter that was trained on the original cell's impedance and discharge curve. A new cell has different internal resistance, so the counter's model no longer matches actual cell voltage. The firmware reads a voltage that maps to one percentage on the old curve but sits at a different true state-of-charge on the new cell. One full discharge-to-shutoff followed by a full uninterrupted charge forces the counter to rebuild its reference points against the new cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCamcorder won't power on after the battery sat in storage\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells left discharged for extended periods can drop below 2.5V per cell, which triggers the BMS protection circuit into a hard lockout state. In lockout, the cell looks dead — no response to the power button, no charge indicator. Connect the camcorder to its charger and leave it for 30–45 minutes without pressing anything; most BMS circuits use a trickle pre-charge path at around 0.1C to recover cells between 2.5V and 3.0V before allowing normal charge current. If the charge LED activates within that window, the cell is recovering.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43409477238874,"sku":"BWCS-NK5BXL-1","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43409477271642,"sku":"BWCS-NK5BXL-2","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43409477304410,"sku":"BWCS-NK5BXL-3","price":27.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-NK5BXL-1.webp?v=1779579814","url":"https:\/\/batteryweb.com\/products\/vivitar-dvr-850w-replacement-battery-37v-750mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}