{"product_id":"sony-srs-xb501-replacement-battery-74v-5200mah-li-ion","title":"Sony SRS-XB501 Replacement Battery 7.4V 5200mAh ID659B","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSony SRS-XB501 \/ SRS-XB501G — 7.4V Li-ion Replacement Battery (ID659B)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 7.4V, 5200mAh (38.48Wh) Li-ion replacement battery for the Sony SRS-XB501 and SRS-XB501G portable Bluetooth speakers. It matches the OEM part number ID659B and fits the original battery bay directly. If your speaker no longer holds a charge or shuts down during playback, this swap restores full operating voltage to the audio and Bluetooth amplifier circuits.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSRS-XB501 and SRS-XB501G compatibility:\u003c\/strong\u003e\n    Both variants run the same 7.4V power rail, use the same connector pinout, and communicate with the same BMS. One battery covers both model suffixes without any hardware modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran the ID659B replacement through full charge and discharge cycles on the SRS-XB501 platform. The BMS handshake cleared on first connection — no fault codes, no charge refusal. Cell voltage held stable across the amplifier's peak current draw at high volume output.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge calibration for the SRS-XB501:\u003c\/strong\u003e\n    Let the battery discharge below 20% at least once a month before recharging. The SRS-XB501 is typically kept topped off near a desk or bag, which causes fuel gauge drift over time. Skipping occasional deeper cycles makes the indicator read inaccurately before the cell actually empties.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the SRS-XB501 cuts out at high volume even on a full charge\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eAt maximum volume, the SRS-XB501's amplifier pulls a sharp current spike that can exceed what a degraded cell will deliver without sagging below the BMS cutoff threshold. The protection circuit reads the voltage dip as a fault condition and interrupts output to avoid cell damage. A fresh cell with low internal resistance handles the transient load without tripping. If drop-outs only happen above 70% volume, internal resistance on the old cell is the cause — not the BMS configuration.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSpeaker won't wake from USB charge after sitting unused for weeks\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells left in deep discharge drop below the minimum acceptance voltage for USB-C PD negotiation — typically under 2.5V per cell on a 7.4V pack. At that level, the charger handshake fails and the speaker appears completely dead. Plug into a USB port rather than a wall adapter first — lower initial current lets the BMS recover the cell incrementally. Once the pack reaches approximately 3.0V per cell, standard charging resumes and the speaker powers on normally.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43416187011162,"sku":"BWCS-SRX501SL-1","price":46.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43416187043930,"sku":"BWCS-SRX501SL-2","price":54.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43416187076698,"sku":"BWCS-SRX501SL-3","price":60.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SRX501SL-1.webp?v=1779760649","url":"https:\/\/batteryweb.com\/products\/sony-srs-xb501-replacement-battery-74v-5200mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}