{"product_id":"digma-e628-replacement-battery-37v-1450mah-li-polymer","title":"Digma E628 Compatible Battery 3.7V 1450mAh 306070PL","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eDigma E628 \/ R657 — 3.7V Li-Polymer Replacement Battery (306070PL)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1450mAh Li-Polymer cell using OEM part number 306070PL. It fits the Digma E628 and R657 e-readers. The physical dimensions are 72.40 × 59.90 × 4.00mm — measure your original cell before ordering if you are unsure.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eE628 and R657 compatibility:\u003c\/strong\u003e\n    Both models draw from the same 3.7V single-cell architecture and share the same connector pinout and BMS handshake protocol. One cell serves both platforms without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell through charge and discharge cycles on the E628 mainboard. The onboard BMS accepted the cell without fault flags, and voltage regulation to the e-ink display controller stayed within spec across the full discharge curve.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-swap charge cycle on the E628 and R657:\u003c\/strong\u003e\n    After installing this cell, connect via USB and allow a full charge before first use. Digma's firmware recalibrates the battery percentage gauge against a complete charge cycle — skip this step and the indicator will report incorrect levels until you complete one full charge.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the E628 shows incorrect battery percentage after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe E628 stores charge curve data from the original cell in firmware memory. When you swap in a new cell, that stored profile no longer matches actual cell behaviour. The gauge reads from a stale reference until the firmware runs a full charge-discharge recalibration cycle. To clear the mismatch, charge the device to 100% without interruption, then use it down to auto-shutoff once. After that single cycle, percentage readouts align to the new cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eE628 not powering on at all after battery replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eIf the device shipped or sat in storage, the cell voltage may have dropped below the E628's minimum boot threshold — typically around 3.0V for this class of mainboard. The device will not attempt to boot below that floor, so a power button press does nothing. Connect a USB charger and leave it for at least 10 minutes before pressing the power button. Once the cell recovers above the boot threshold, the device will start normally.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43360239517786,"sku":"BWCS-PTK626SL-1","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43360239550554,"sku":"BWCS-PTK626SL-2","price":29.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43360239583322,"sku":"BWCS-PTK626SL-3","price":32.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-PTK626SL-1.webp?v=1778611023","url":"https:\/\/batteryweb.com\/products\/digma-e628-replacement-battery-37v-1450mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}