{"product_id":"maxcom-mm238-replacement-battery-37v-1200mah-li-ion","title":"MaxCom MM238 Replacement Battery 3.7V 1200mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eMaxCom MM238 — 3.7V Li-ion Replacement Battery (MM238)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1200mAh lithium-ion battery for the MaxCom MM238 mobile phone. It fits the MM238 directly, matching the original cell's voltage and connector. Dimensions are 60.00 × 43.80 × 4.50mm — confirm against your existing battery before ordering.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMM238 cell fitment:\u003c\/strong\u003e\n    The MM238 uses a compact single-cell 3.7V Li-ion pack with a low-current BMS suited to the phone's basic modem and display load. Voltage rail and connector position match the original — no modification needed.\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 MM238 platform. The BMS accepted charge from the phone's onboard charge IC without tripping, and the protection circuit held under sustained screen-on and call load.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    On first use after installation, run one complete discharge-to-charge cycle without interruption. This lets the MM238's fuel gauge IC map the new cell's discharge curve and report accurate percentages from cycle two onward.\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 MM238 after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA new Li-ion cell has a slightly different voltage-versus-capacity curve than the worn cell it replaces. The MM238's fuel gauge IC still holds the old curve in memory, so it reads 25% when the actual cell voltage is already close to the low-voltage cutoff. Under modem or screen load, current draw spikes and the cell voltage drops past the BMS cutoff instantly — the phone shuts off. One full discharge-charge cycle rewrites the reference curve. After that cycle, shutdowns at false percentages stop.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eMM238 not powering on after the replacement battery sat in storage\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells self-discharge during storage. If the cell voltage has dropped below approximately 2.5V, the BMS locks out to prevent damage — the phone will not respond to the power button or a standard charger. Connect the phone to a wall charger rated at 5V and leave it for 20–30 minutes without pressing anything. Most charge ICs apply a low-current trickle to recover a locked-out cell. If the charging indicator appears, continue a full charge before first use.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405046087770,"sku":"BWCS-OYB130SL-1","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405046120538,"sku":"BWCS-OYB130SL-2","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405046153306,"sku":"BWCS-OYB130SL-3","price":27.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-OYB130SL-1.webp?v=1779369883","url":"https:\/\/batteryweb.com\/products\/maxcom-mm238-replacement-battery-37v-1200mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}