{"product_id":"acer-liquid-z4-replacement-battery-37v-1250mah-li-ion","title":"Acer Liquid Z4 BAT-611 Replacement Battery 3.7V 1250mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAcer Liquid Z4 \/ Z140 \/ Z160 — 3.7V Li-ion Replacement Battery (BAT-611)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1250mAh Li-ion replacement battery for the Acer Liquid Z4, Z140, and Z160 smartphones. OEM part numbers BAT-611 and KT.0010B.006 both apply to this cell. It slots directly into the rear battery compartment and powers the processor, display, and all wireless functions.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eZ4 \/ Z140 \/ Z160 platform fit:\u003c\/strong\u003e\n    These three models share the same battery bay dimensions, connector pinout, and BMS handshake protocol — one cell covers all three. The 64.85 × 49.45 × 4.45mm form factor matches the original chassis tolerances 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 a full charge and discharge sequence on the Liquid Z4. The BMS accepted the cell on first connection, voltage sat at 3.7V nominal under screen-on load, and the charge IC completed a clean taper cycle without tripping a protection flag.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After installation, disable fast charging and run one complete discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging begins on an uncalibrated cell — skipping this step causes erratic percentage readings from the first charge onward.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Liquid Z4 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Liquid Z4 uses a coulomb-counter-based fuel gauge IC that holds calibration data from the original cell's charge curve. When a new cell goes in, the IC is still referencing the old curve — so reported percentage drifts away from actual state of charge almost immediately. The fix is one full discharge to near-empty followed by an uninterrupted charge to 100% at standard rate, no fast charging. After that cycle, the IC re-anchors its empty and full reference points to the new cell. Expect the percentage display to stabilise from the second cycle onward.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the replacement cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the cell voltage drops sharply under combined modem and display load — a voltage cliff the fuel gauge didn't predict because it hasn't completed a calibration cycle. The phone's protection circuit trips the shutdown before the display reads zero. It is not a faulty battery. Run the device down to automatic shutoff once, then charge fully to 100% without interruption. After that, the fuel gauge has a real low-voltage anchor and the shutdowns stop.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43404251398234,"sku":"BWCS-ACZ400SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43404251431002,"sku":"BWCS-ACZ400SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43404251463770,"sku":"BWCS-ACZ400SL-3","price":28.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-ACZ400SL-1.webp?v=1779369511","url":"https:\/\/batteryweb.com\/products\/acer-liquid-z4-replacement-battery-37v-1250mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}