{"product_id":"bt-synergy-2100-replacement-battery-24v-600mah-ni-mh","title":"BT Synergy 2100 Replacement Battery 2.4V 600mAh Ni-MH","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eBT Synergy 2100 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 replacement battery for the BT Synergy 2100 cordless phone handset. It fits the Synergy 2100, 2110, 2120, and 2150 models. Swap it in when the original pack no longer holds a charge or fails to charge from the base station.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSynergy 2100, 2110, 2120, 2150 compatibility:\u003c\/strong\u003e\n    These four handsets share the same 2.4V two-cell Ni-MH pack format, physical footprint (45 × 21 × 10mm), and base-station charging contacts. One battery fits all four variants 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 a BT Synergy handset. The battery accepted a full charge from the base cradle, and the BMS held voltage stable through standby and active call loads without tripping.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-charge protocol for Ni-MH handsets:\u003c\/strong\u003e\n    Place the handset in the base for a full 16 hours before first use. Ni-MH cordless phone batteries ship in a partially discharged state — a slow initial charge lets each cell reach rated capacity. Skipping this step is the main reason new batteries underperform out of the box.\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 fitting a new pack\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eBT Synergy bases use a voltage threshold to detect whether a battery is present and ready to charge. A new Ni-MH pack that has sat in storage can drop below this threshold — typically under 2.0V — and the base either ignores it or flashes an error. The fix is a slow trickle: leave the handset seated in the base undisturbed for several hours. Most bases will begin the charge cycle once the pack recovers enough resting voltage to cross the detection threshold.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eRange drops noticeably when the Ni-MH pack gets low\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eDECT handsets draw a surge of current each time the RF transmitter fires. When a Ni-MH cell is below roughly 2.2V under load, that current draw causes a voltage sag that the handset reads as a low-battery condition — and it reduces transmit power to protect the circuit. The result is shorter range and broken audio before the battery indicator shows empty. If range drops before the battery icon is low, check the resting voltage with a meter — a healthy charged pack should read 2.7–2.8V at rest.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43339991449690,"sku":"BWCS-BTB500CL-1","price":21.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43339991482458,"sku":"BWCS-BTB500CL-2","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43339991515226,"sku":"BWCS-BTB500CL-3","price":26.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-BTB500CL-1.webp?v=1778366983","url":"https:\/\/batteryweb.com\/products\/bt-synergy-2100-replacement-battery-24v-600mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}