{"product_id":"topcon-total-station-gm-52-replacement-battery-74v-5500mah-li-ion","title":"Topcon Total Station GM-52 Replacement Battery 7.4V 5500mAh","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, 5500mAh (40.7Wh) Li-ion pack replaces the internal battery in the Topcon GM-52 total station and RC-5 remote controller. Both units share the same voltage rail and physical form factor, so one replacement covers either device. Dimensions are 70.60 × 39.50 × 39.60mm — check your existing pack before ordering if you are unsure which unit you have.\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    Both the GM-52 total station and RC-5 remote operate on a 7.4V Li-ion platform with matching connector pinouts and BMS handshake requirements. A single replacement pack services either unit 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 and discharge sequences, monitoring BMS cutoff behaviour under simulated EDM and servo-drive load. The BMS held stable across motor-start current spikes without triggering a premature shutdown.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePre-deployment calibration cycle:\u003c\/strong\u003e\n    After fitting this pack, run a full calibration cycle through the GM-52 instrument menu before heading to site. The instrument maps battery state during that routine — skip it and the low-battery indicator will fire early on your first measurement session, even with a full charge.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eGM-52 shutting down mid-measurement during EDM or servo drive\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe GM-52 draws a sharp current spike when the EDM fires or the servo motor drives a motorised aim sequence. An aged or deeply discharged cell cannot sustain voltage through that spike, so the BMS trips and cuts power mid-operation. A fresh cell with solid internal resistance handles the surge without a voltage collapse. If the instrument was cutting out consistently near the end of a session, that pattern confirms cell degradation rather than a firmware or instrument fault.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePack will not charge after the GM-52 or RC-5 sat unused for months\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells self-discharge during storage. If voltage drops below roughly 2.5V per cell (5.0V pack total), the BMS enters a protection state and blocks normal charging to prevent cell damage. Most Topcon chargers will not initiate a charge cycle at that point and show no indication light or a fault blink. Place the pack on charge for 30–60 minutes — some chargers apply a slow recovery current that brings the cells back above the BMS recovery threshold. If the charger still shows no activity after that window, measure pack voltage at the terminals; anything below 5.0V indicates deep discharge and the pack may not recover.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43360544358490,"sku":"BWCS-SDC720SL-1","price":77.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43360544391258,"sku":"BWCS-SDC720SL-2","price":91.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43360544424026,"sku":"BWCS-SDC720SL-3","price":101.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SDC720SL-1.webp?v=1778615963","url":"https:\/\/batteryweb.com\/products\/topcon-total-station-gm-52-replacement-battery-74v-5500mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}