{"product_id":"relm-rpu7500-replacement-battery-74v-2100mah-li-ion","title":"Relm RPU7500 Replacement Battery BL1703 7.4V 2100mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eRelm RPU7500 \/ RPV7500 — 7.4V Li-ion Replacement Battery (BL1703)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThe BL1703 is a 7.4V, 2100mAh lithium-ion battery for the Relm RPU7500 and RPV7500 portable two-way radios. It replaces the original pack when capacity has faded or the radio no longer holds a charge between shifts. Voltage and connector match the OEM spec exactly.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eRPU7500 and RPV7500 platform fit:\u003c\/strong\u003e\n    Both models run the same 7.4V power rail, share the BL1703 connector footprint, and use the same BMS handshake protocol — a single pack covers either radio 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 full charge-discharge runs on the RPU7500 platform. The BMS held steady across transmit current spikes and reported no false cutoffs under sustained PTT load.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst insertion into the charger dock:\u003c\/strong\u003e\n    If the dock LED shows a fault on first insertion, remove the pack, wipe the gold contact strip with a dry cloth, and reseat it firmly. The RPU7500 dock requires a clean contact cycle to complete the BMS handshake before charging begins.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eRPU7500 cuts out mid-transmission on a new BL1703\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eA new lithium-ion pack ships at storage voltage — typically 3.6–3.7V per cell, not full charge. When you key up on a new battery straight out of the box, the transmit current spike can pull the cell voltage below the BMS undervoltage threshold, triggering an immediate cutoff. The radio cuts out not because the pack is faulty, but because the cells haven't been brought to operating charge yet. Charge the pack fully in the dock before the first transmission — the BMS will not trip once the cells are at 4.1–4.2V per cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBar indicator shows one fewer bar than expected after inserting a new BL1703\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe RPU7500 uses a voltage-threshold bar indicator — each bar corresponds to a voltage window, not a fuel gauge calculation. A new pack at storage voltage sits in a lower threshold window, so the display shows one or two bars even though the pack is not depleted. This is not a capacity fault. Place the pack in the dock, let it reach a full charge cycle, and the bar indicator will reflect the correct resting voltage — typically four bars at 8.2–8.4V across the pack.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43426304360538,"sku":"BWCS-HTC780TW-1","price":43.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43426304393306,"sku":"BWCS-HTC780TW-2","price":51.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43426304426074,"sku":"BWCS-HTC780TW-3","price":56.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-HTC780TW-1.webp?v=1779930583","url":"https:\/\/batteryweb.com\/products\/relm-rpu7500-replacement-battery-74v-2100mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}