{"product_id":"topcon-total-station-gm-52-replacement-battery-74v-2600mah-li-ion","title":"Topcon Total Station GM-52 Compatible Battery 7.4V 2600mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eTopcon Total Station GM-52 \/ RC-5 — 7.4V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 7.4V 2600mAh (19.24Wh) Li-ion battery replaces the original pack in the Topcon Total Station GM-52 and RC-5. Both instruments share the same battery bay dimensions, connector pinout, and BMS handshake protocol, so one pack covers both units. It is a direct swap for field surveyors who need a live spare during long deployment days.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eGM-52 and RC-5 compatibility:\u003c\/strong\u003e\n    These two units share a common 7.4V power rail, identical battery bay geometry (70.60 × 38.50 × 20.20mm), and the same BMS communication interface. No firmware difference affects pack recognition between them.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this pack under sustained angle-and-distance measurement loads. The BMS held the 7.4V rail stable through repeated EDM pulses and servo-motor initialisation spikes without tripping into protection mode.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation calibration cycle:\u003c\/strong\u003e\n    After fitting this pack, run a full calibration cycle through the GM-52 instrument menu before field deployment. The instrument maps battery state during calibration — skipping this step causes premature low-battery warnings during your first measurement session.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBMS cutoff during EDM and servo-motor initialisation on the GM-52\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eWhen the GM-52 powers up, the EDM module and servo-motors draw a combined inrush current that can briefly exceed the BMS overcurrent threshold on a depleted or cold pack. The BMS interprets this spike as a fault and cuts output — the instrument shuts off immediately after startup. A pack charged to at least 7.8V before heading to site handles the inrush without triggering cutoff. If shutdowns persist, check ambient temperature: below 5°C, Li-ion internal resistance rises sharply and amplifies the spike.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eGM-52 shows inconsistent battery percentage immediately after a new pack is fitted\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe GM-52 uses a voltage-threshold method to estimate charge level, not a standalone fuel gauge chip. When a new pack is fitted, the instrument has no charge history for it, so early percentage readings can jump or reset at reboot until the instrument builds a reference curve. Run two full charge-to-discharge cycles in normal measurement use and the display will stabilise. If the reading still fluctuates after two cycles, check cell voltage directly — a healthy fully charged pack should read between 8.3V and 8.4V at the terminals.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43360542589018,"sku":"BWCS-SDC710SL-1","price":61.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43360542621786,"sku":"BWCS-SDC710SL-2","price":72.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43360542654554,"sku":"BWCS-SDC710SL-3","price":80.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SDC710SL-1.webp?v=1778615963","url":"https:\/\/batteryweb.com\/products\/topcon-total-station-gm-52-replacement-battery-74v-2600mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}