{"product_id":"fritzfon-dect-mt-d-replacement-battery-24v-600mah-ni-mh","title":"FRITZ!Fon DECT MT-D Replacement Battery 2.4V 600mAh Ni-MH","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eFRITZ!Fon DECT MT-D Series — 2.4V Ni-MH Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 2.4V, 600mAh Ni-MH rechargeable battery for the FRITZ!Fon DECT MT-D cordless telephone handset. It fits the DECT MT-D, MT-D VOIP DECT, and VOIP DECT variants. No OEM part number is published for this cell — match by model name and the physical dimensions: 35.40 × 32.50 × 6.70mm.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMT-D and VOIP DECT compatibility:\u003c\/strong\u003e\n    All three listed variants run the same 2.4V two-cell NiMH pack on the same connector footprint. The BMS in the base station is tuned to this voltage range — swapping to a higher-voltage chemistry will trigger a charge fault.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this pack through the FRITZ!Fon base station and confirmed the charge-acceptance handshake completes normally. The BMS accepted the pack without error flags on both trickle and full charge phases.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst charge protocol for NiMH handsets:\u003c\/strong\u003e\n    After installing, seat the handset in the base and leave it for a full 16 hours before the first call. NiMH cells from storage have suppressed capacity — a slow initial charge lets the chemistry reach its rated 600mAh ceiling. Skipping this step means the first few cycles will feel short.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBase station showing no charge or error light after battery swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eFRITZ!Fon base stations check for a minimum voltage before committing to a charge cycle. A NiMH pack that has sat in storage can drop below 2.0V per cell, which falls outside the base's acceptance window. The base interprets this as a faulty or missing battery and shows an error instead of a charge indicator. To recover: briefly connect the pack to a standalone NiMH charger at 60mA until it reads at least 2.2V, then re-seat it in the FRITZ!Fon base.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eHandset loses DECT pairing after battery replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eRemoving the battery from a DECT handset cuts all power to the registration memory on some MT-D firmware versions. The base station no longer recognises the handset after power is restored. This is not a battery fault — it is a pairing memory wipe caused by the power interruption. Re-register the handset from the base station menu using the standard FRITZ!Box DECT pairing sequence to restore the link.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43340101779546,"sku":"BWCS-SDT500CL-1","price":21.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 2 Year","offer_id":43340101812314,"sku":"BWCS-SDT500CL-2","price":24.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 3 Year","offer_id":43340101845082,"sku":"BWCS-SDT500CL-3","price":26.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SDT500CL-1.webp?v=1778367188","url":"https:\/\/batteryweb.com\/products\/fritzfon-dect-mt-d-replacement-battery-24v-600mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}