{"product_id":"sony-spp-52-replacement-battery-24v-300mah-ni-mh","title":"Sony BP-T21 Cordless Phone Replacement Battery 2.4V 300mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSony SPP-52 \/ SPP-62 Series — 2.4V Ni-MH Replacement Battery (BP-T21)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 2.4V, 300mAh Ni-MH replacement battery for Sony cordless phones using the BP-T21 pack. It fits the SPP-52, SPP-62, XC801, and XC810 handsets, along with three additional models in the same family. When the original pack no longer holds a charge, this unit restores normal handset operation.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSPP and XC series compatibility:\u003c\/strong\u003e\n    These Sony handsets share the same 2.4V two-cell NiMH voltage rail, identical connector footprint, and cradle-charge interface — which is why one pack covers both the SPP and XC model lines without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this pack through charge and discharge on the SPP-52 handset. The BMS accepted charge current from the base station on the first seat, and voltage held steady across the full discharge curve without mid-cycle drop-off.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst charge after installation:\u003c\/strong\u003e\n    After fitting the new pack, seat the handset in the base for a full 16-hour charge before use. NiMH cells in cordless phones are slow-charged by the base station — cutting this short on the first cycle reduces how much capacity the cells reach at full condition.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eTalk time shorter than the original battery after replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eNiMH cells ship in a partially discharged state and need three to five full charge-and-use cycles before they reach rated capacity. On the first cycle, actual talk time will be noticeably shorter than the original battery at its best. Each subsequent full cycle conditions the cells further. By cycle five, the pack should be delivering close to its rated 300mAh.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBase station showing a charging error or no-charge light after swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eIf the base station flashes an error or fails to show a charge indicator after you install the new battery, the NiMH pack voltage has likely dropped below the threshold the base uses to confirm a valid battery is seated. Remove the handset, wait 10 seconds, and reseat it firmly. If the error persists, the pack voltage may need a recovery charge — use a standalone NiMH charger at 0.1C (30mA for this pack) for one hour before returning it to the base.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43340066095194,"sku":"BWCS-BPT21CL-1","price":19.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43340066127962,"sku":"BWCS-BPT21CL-2","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43340066160730,"sku":"BWCS-BPT21CL-3","price":23.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-BPT21CL-1.webp?v=1778367024","url":"https:\/\/batteryweb.com\/products\/sony-spp-52-replacement-battery-24v-300mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}