{"product_id":"testo-350k-analyzer-replacement-battery-111v-5200mah-li-ion","title":"Testo 350K Analyzer 11.1V Replacement Battery 0515 0039","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eTesto 350K Analyzer — 11.1V Li-ion Replacement Battery (0515 0039)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 11.1V 5200mAh (57.72Wh) Li-ion pack replaces the OEM battery in the Testo 350K and 350 GAS Analyzer. Both instruments are portable combustion and emissions analyzers used for flue gas measurement in HVAC and industrial survey work. The pack slots into the instrument's battery bay and connects through the same BMS communication interface as the original.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003e350K and 350 GAS compatibility:\u003c\/strong\u003e\n    Both models run the same 11.1V three-cell architecture and share the OEM part number 0515 0039. The battery connector pinout and BMS handshake protocol are identical across both units, so one pack covers either instrument 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 the 350K's probe initialisation sequence, which draws a short current spike as the electrochemical sensors power up. The BMS held the rail without tripping into protection mode, and cell voltage recovered cleanly between measurement cycles.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePre-deployment calibration cycle:\u003c\/strong\u003e\n    After installing a fresh pack, run a full calibration cycle through the instrument's menu before heading to site. The 350K maps battery state during calibration — skipping this causes the instrument to flag premature low-battery warnings during the first measurement session in the field.\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 350K sat unused in a carry case for months\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells self-discharge over time, and if the pack drops below roughly 2.5V per cell during storage, the BMS trips into deep-discharge protection and the instrument will not power on at all. The charger may also show no charge activity because it reads the pack as unrecoverable. Most chargers with a recovery or boost mode can push a small current into the pack to lift cell voltage above the BMS re-enable threshold. Connect the battery to the charger for at least 30 minutes — if cell voltage climbs above 9V total, normal charge will resume automatically.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eReadings resetting or logging gaps during a sustained measurement session\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eWhen all sensor channels are active simultaneously during a long flue gas survey, the combined draw from the electrochemical cells, pump motor, and display creates a sustained load the aged OEM pack can no longer support cleanly. Voltage sags under this load, and the instrument interprets a brief undervoltage event as a power fault — resetting the active log or dropping data points. This is not a firmware issue; it is a capacity problem. A fresh pack at 5200mAh holds the voltage rail flat across the full sensor load without dropout.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43360734085210,"sku":"BWCS-TES351SL-1","price":66.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43360734117978,"sku":"BWCS-TES351SL-2","price":78.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43360734150746,"sku":"BWCS-TES351SL-3","price":87.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-TES351SL-1.webp?v=1778616210","url":"https:\/\/batteryweb.com\/products\/testo-350k-analyzer-replacement-battery-111v-5200mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}