{"product_id":"survey-equipment-replacement-battery-74v-2000mah-li-ion","title":"Survey 7.4V Replacement Battery 29518 2000mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSurvey Equipment (29518 \/ 38403 \/ 46607) — 7.4V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 7.4V, 2000mAh Li-ion battery for Survey brand portable surveying tools and field measurement instruments. It replaces OEM part numbers 29518, 38403, 46607, 52030, C8872A, and EI-D-LI1. The pack fits instruments used in construction layout, engineering surveys, and field data logging.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMulti-part-number compatibility:\u003c\/strong\u003e\n    Survey issued multiple OEM part numbers across instrument revisions, but the voltage rail, connector pinout, and BMS handshake protocol remain consistent across all six references listed above. One pack covers the full range.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this pack through charge, idle, and sustained sensor-load discharge. The BMS held cutoff thresholds correctly and did not trip during probe initialisation draws at power-up.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-use calibration step:\u003c\/strong\u003e\n    After installing this pack, run a full calibration cycle through the instrument menu before field deployment. The instrument maps battery state during calibration — skipping this step causes premature low-battery warnings to appear on the first measurement session, even with a fully charged pack.\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 instrument sat unused in a carry case for months\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells self-discharge during storage. If the pack drops below roughly 2.5V per cell, the BMS enters a protective sleep state and blocks normal charge current. The instrument will show no charge activity and may not power on at all. A compatible charger with a pre-charge or recovery mode can push a low-current trickle into the pack to lift cell voltage above the recovery threshold before standard charging resumes.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eReadings drifting or resetting mid-session during continuous data logging\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eSustained sensor load draws more current than intermittent spot measurements. If cell impedance has risen — either in an aged original pack or a deeply discharged replacement — voltage sags under that continuous load and the instrument interprets the drop as a low-battery condition, triggering a reset or data save interrupt. Check that the pack rested at or above 8.2V before the session started. A pack reading 7.6V at rest under sustained load will sag further and trip the cutoff threshold mid-log.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43360794706010,"sku":"BWCS-LI1SL-1","price":32.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43360794738778,"sku":"BWCS-LI1SL-2","price":37.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43360794771546,"sku":"BWCS-LI1SL-3","price":41.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-LI1SL-1.webp?v=1778616259","url":"https:\/\/batteryweb.com\/products\/survey-equipment-replacement-battery-74v-2000mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}