{"product_id":"rover-s1-replacement-battery-37v-1500mah-li-ion","title":"Rover S1 Replacement Battery 3.7V 1500mAh PE2021","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eRover S1 \/ P1 — 3.7V Li-ion 1500mAh Replacement Battery (PE2021 \/ BTR-4100)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V Li-ion battery rated at 1500mAh (5.55Wh), built to fit the Rover S1 and P1 smartphones. It replaces OEM part numbers PE2021 and BTR-4100. If your original cell has degraded or failed completely, this is the direct swap.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eS1 and P1 compatibility:\u003c\/strong\u003e\n    Both models share the same battery bay dimensions, connector pinout, and BMS handshake protocol — one cell covers both platforms 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 discharge on the S1 platform. The BMS accepted the cell on first connect, charge termination triggered correctly at 4.2V, and protection cutoff engaged as expected at the low-voltage threshold.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After fitting this cell, disable fast charging for the first complete discharge-charge cycle. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging begins on an uncalibrated counter.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the Rover S1 after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the fuel gauge IC is still running the discharge curve of the original, degraded cell. The new cell holds a higher actual voltage at any given percentage, but the gauge reports depletion early because its coulomb counter was calibrated to the old cell. Under modem or screen load, the system sees a voltage that doesn't match its stored curve and shuts down as a protection measure. One full uninterrupted discharge to near-zero, followed by a full charge to 100%, forces the IC to re-anchor its curve to the new cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eRover S1 not powering on after the replacement battery sat in storage\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells self-discharge over time. If this battery shipped or was stored in a discharged state, the cell voltage may have dropped below 2.5V — the threshold at which the BMS locks out to prevent damage. The phone won't respond to the power button and may show no charge indicator. Connect it to a wall charger, not a USB port, and leave it for 15–20 minutes before attempting to power on. Most BMS circuits will accept a trickle from the charge IC and unlock once the cell climbs back above 3.0V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405151666266,"sku":"BWCS-SP230SL-1","price":27.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 2 Year","offer_id":43405151699034,"sku":"BWCS-SP230SL-2","price":30.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 3 Year","offer_id":43405151731802,"sku":"BWCS-SP230SL-3","price":33.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SP230SL-big.webp?v=1779370298","url":"https:\/\/batteryweb.com\/products\/rover-s1-replacement-battery-37v-1500mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}