{"product_id":"sonel-pqm-711-replacement-battery-37v-5200mah-li-ion","title":"Sonel WAAKU11 PQM-711 Replacement Battery 3.7V 5200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSonel PQM-711 \/ PQM-710 Series — 3.7V Li-ion Replacement Battery (WAAKU11)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V 5200mAh Li-ion pack replaces the original WAAKU11 \/ AKU-11 battery in the Sonel PQM-711, PQM-710, PQM-703, and PQM-702 power quality analyzers. These instruments are used by electrical contractors and technicians for on-site measurements of voltage, current, harmonics, and power factor in industrial and commercial installations. Capacity is taken directly from product data at 19.24Wh.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePQM-700 series compatibility:\u003c\/strong\u003e\n    The PQM-702, PQM-703, PQM-710, and PQM-711 share the same battery bay dimensions, connector pinout, and BMS handshake protocol — which is why a single pack covers all four models. Swapping between units in the field carries no electrical risk if the housing seats fully.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this pack through probe module initialisation and sustained logging loads on the PQM-711. The BMS held voltage within spec across the full measurement session and did not trip during the current spike at sensor power-up.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-install calibration step:\u003c\/strong\u003e\n    After fitting this pack, run a full calibration cycle through the instrument menu before field deployment. The PQM-711 maps battery state during calibration — skipping this causes premature low-battery warnings to appear during your 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 PQM-711 sat unused in a carry case for months\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells in low-draw instruments self-discharge slowly during storage. If the pack voltage drops below approximately 2.5V per cell, the BMS enters a protective lockout state and the instrument will not power on — even when placed on charge. The charger sees no valid handshake and either shows no indicator or a fault light. To recover the pack, apply a low-current pre-charge using a compatible bench charger that supports trickle mode until cell voltage climbs above 3.0V, at which point the BMS resets and normal charging resumes.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eVoltage dropout causing readings to reset or drift mid-logging session\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eDuring sustained multi-channel logging — particularly when current probes and voltage inputs are all active — the PQM-711 draws a combined load that can pull cell voltage below the BMS discharge threshold momentarily. The instrument interprets this as a low-battery event, interrupts the logging session, and in some cases resets the display or loses the current measurement record. This is not a firmware fault. Check that the pack is fully charged before a long session and that all probe connectors are fully seated — a loose connection adds resistive load that worsens voltage sag under peak draw.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43360487637082,"sku":"BWCS-SQM710SL-1","price":32.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43360487669850,"sku":"BWCS-SQM710SL-2","price":37.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43360487702618,"sku":"BWCS-SQM710SL-3","price":41.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SQM710SL-1.webp?v=1778615901","url":"https:\/\/batteryweb.com\/products\/sonel-pqm-711-replacement-battery-37v-5200mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}