{"product_id":"mini-keyboard-rt-mwk08-replacement-battery-37v-900mah-li-ion","title":"Mini Keyboard RT-MWK08 Replacement Battery 3.7V 900mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eMini Keyboard RT-MWK08 — 3.7V Li-ion Replacement Battery (SL-1102A)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V 900mAh (3.33Wh) Li-ion cell replaces the internal battery in the Mini Keyboard RT-MWK08 compact Bluetooth keyboard. The RT-MWK08 pairs wirelessly with smartphones and tablets, and this replacement restores the charge capacity lost in degraded or failed original cells. Dimensions are 53.00 x 34.00 x 4.80mm — measure your existing cell before fitting.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eRT-MWK08 fitment:\u003c\/strong\u003e\n    The RT-MWK08 uses a single-cell flat pack with a specific footprint. The SL-1102A matches the physical envelope and connector orientation so the keyboard's charge circuit sees the correct cell topology 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 RT-MWK08's charge circuit and confirmed the BMS accepted the charge without triggering cutoff. Discharge behaviour stayed within spec across Bluetooth active-pairing and idle standby states.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration after swap:\u003c\/strong\u003e\n    After fitting the SL-1102A, run one complete discharge down to auto-shutoff and then charge fully without interruption. The keyboard's fuel gauge IC needs one full cycle to map the new cell's discharge curve — skipping this causes erratic percentage readings from the paired device.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the RT-MWK08 shows wrong battery percentage on the paired device after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe RT-MWK08 reports battery level to the host device over Bluetooth using a value calculated by the onboard fuel gauge IC. That IC was calibrated against the original cell's discharge curve. A new cell has a slightly different internal resistance profile, so the coulomb counter reads high or low until it re-anchors. One full discharge-to-shutoff followed by an uninterrupted charge to 100% resets the reference points. After that cycle, reported percentages track the actual cell state accurately.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eRT-MWK08 not powering on after the battery sat discharged in storage\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells that drop below approximately 2.5V trigger a BMS lockout to prevent damage from deep discharge. If the RT-MWK08 was stored unused for months, the cell may have self-discharged past this threshold and the BMS will block normal charging. Connect the keyboard to a USB power source and leave it for 15–20 minutes — some charge controllers include a trickle pre-charge mode that slowly brings the cell back above the 2.5V floor before switching to standard CC\/CV charging. If the device still shows no sign of life after 30 minutes, the original cell has likely failed below recovery voltage and the SL-1102A replacement is the correct next step.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405025804378,"sku":"BWCS-MY890SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405025837146,"sku":"BWCS-MY890SL-2","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405025869914,"sku":"BWCS-MY890SL-3","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MY890SL-1.webp?v=1778767243","url":"https:\/\/batteryweb.com\/products\/mini-keyboard-rt-mwk08-replacement-battery-37v-900mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}