{"product_id":"carlson-brx7-replacement-battery-74v-2600mah-li-ion","title":"Carlson BRx7 Survey Instrument Replacement Battery 7.4V 2600mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eCarlson BRx7 \/ Hemisphere S631 — 7.4V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 7.4V 2600mAh (19.24Wh) lithium-ion battery fits the Carlson BRx7 handheld data collector, the Base Receiver Smart Antenna Total Station, and the Base Rover Receiver Hemisphere S631. All three units share the same voltage rail, physical form factor, and BMS handshake protocol. Capacity figures come from the product data — not from third-party claims.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eBRx7, Base Receiver, and S631 compatibility:\u003c\/strong\u003e\n    These units run the same 7.4V battery bus with a matching connector pinout and BMS communication line. Swapping between them does not require a firmware change — the instrument reads pack state through the same data pin on all three platforms.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this pack through a simulated survey session — powering satellite acquisition, active GNSS logging, and Bluetooth data transfer simultaneously. The BMS held the output rail steady through the combined draw without triggering an overcurrent cutoff.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eField deployment prep for survey instruments:\u003c\/strong\u003e\n    After fitting this pack, navigate to the instrument's battery calibration or system check menu before heading to site. The BRx7 maps voltage thresholds to percentage during this step — skipping it causes the low-battery warning to fire early on the first logging session.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBMS lockout after the BRx7 sat unused in a carry case for months\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells self-discharge slowly in storage. If the pack voltage drops below roughly 2.5V per cell — around 5.0V total for a 2S pack — the BMS trips a deep-discharge lockout and the instrument will not power on even with a charger connected. Standard chargers see zero voltage at the terminals and refuse to initiate a charge cycle. To recover, use a charger with a manual \"boost\" or \"recovery\" mode that can push a low-current pulse (around 100mA) until cell voltage climbs above 3.0V per cell, at which point normal charging resumes.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBRx7 shuts down instantly when satellite acquisition starts\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eGNSS acquisition draws a brief but sharp current spike as the RF front-end and correlator circuits initialise — this can exceed the BMS overcurrent threshold on a degraded or partially discharged pack, triggering an immediate cutoff. The instrument appears to power on normally, then drops dead the moment it starts scanning for satellites. Charge the pack fully to 8.4V before the next attempt, then power on the BRx7 with the survey app already closed so the RF module does not initialise until the voltage rail is stable.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43360515096666,"sku":"BWCS-TOX110SL-1","price":67.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43360515129434,"sku":"BWCS-TOX110SL-2","price":79.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43360515162202,"sku":"BWCS-TOX110SL-3","price":88.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-TOX110SL-1.webp?v=1778615963","url":"https:\/\/batteryweb.com\/products\/carlson-brx7-replacement-battery-74v-2600mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}