{"product_id":"radiwow-r-108-replacement-battery-37v-1200mah-li-ion","title":"RADIWOW R-108 Replacement Battery 3.7V 1200mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eRADIWOW R-108 — 3.7V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V, 1200mAh Li-ion cell replaces the original battery in the RADIWOW R-108 portable radio receiver. It matches the original voltage and physical footprint at 53.00 x 33.90 x 5.70mm. Capacity figure is taken from the product specification — 4.44Wh.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eR-108 fit and voltage rail:\u003c\/strong\u003e\n    The R-108 runs a single-cell 3.7V Li-ion architecture. This replacement matches that voltage rail exactly. A mismatch here would push the radio's internal regulator out of spec and cause audio distortion or no output at all.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through the R-108's charge circuit and confirmed the BMS accepted the charge handshake without flagging a fault. Discharge held stable voltage through the radio's tuner and amplifier stages with no cutoff event.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration after install:\u003c\/strong\u003e\n    After fitting this cell, run one complete discharge down to automatic shutoff, then charge uninterrupted to 100% before normal use. The R-108's fuel gauge IC was calibrated against the old cell's discharge curve — skipping this step causes percentage jumps and early low-battery warnings.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the R-108 shuts off suddenly at 20–30% after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe R-108's fuel gauge IC stores a discharge curve from the original cell. A new cell has a different internal resistance profile, so the IC underestimates remaining capacity. Under load — when the tuner locks onto a signal and the amplifier draws peak current — the voltage sags below the cutoff threshold even though the displayed percentage still reads 20–30%. The IC hasn't mapped the new cell's actual knee voltage yet. One full discharge-charge cycle forces the coulomb counter to rebuild its reference curve against the new cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eR-108 shows incorrect battery percentage after replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens because the fuel gauge IC recalibrates continuously against historical charge and discharge data. Swapping the cell resets that history to a mismatch. The displayed percentage can jump erratically — sometimes reading full, then dropping ten points in seconds. This is a calibration state, not a fault with the cell. Discharge the R-108 completely until it shuts itself off, then charge to 4.2V in one uninterrupted session to reset the fuel gauge baseline.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43404140773466,"sku":"BWCS-AVC120SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43404140806234,"sku":"BWCS-AVC120SL-2","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43404140839002,"sku":"BWCS-AVC120SL-3","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-AVC120SL-1.webp?v=1779369080","url":"https:\/\/batteryweb.com\/products\/radiwow-r-108-replacement-battery-37v-1200mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}