{"product_id":"jdsu-viavi-mts-2000-replacement-battery-74v-5000mah-li-polymer","title":"JDSU VIAVI MTS-2000 Replacement Battery 7.4V 5000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eJDSU VIAVI MTS-2000 \/ Smart OTDR — 7.4V Li-Polymer Replacement Battery (4-JS001P)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 7.4V 5000mAh Li-Polymer replacement battery for the JDSU VIAVI MTS-2000 portable optical test platform and Smart OTDR series, including the 100AS and E100AS. It replaces OEM part numbers 4-JS001P and 636395. Capacity is 37Wh — matching the original pack specification.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMTS-2000 and Smart OTDR compatibility:\u003c\/strong\u003e\n    These models share the same 7.4V two-cell Li-Polymer architecture, physical footprint, and BMS handshake protocol. The same pack covers fibre and copper test configurations without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this pack through probe initialisation sequences on the MTS-2000. The BMS held stable through the current spike at OTDR port power-up — a point where degraded cells often trip the protection circuit and kill the session.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-use calibration on MTS-2000:\u003c\/strong\u003e\n    After installing, run a full calibration cycle through the instrument menu before field deployment. The MTS-2000 maps battery state during calibration. Skipping this step causes premature low-battery warnings during 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 MTS-2000 sat unused in a carry case for months\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-Polymer cells self-discharge slowly over time. If the instrument sat unused long enough, the pack voltage may have dropped below the BMS recovery threshold — typically around 2.5V per cell for a 7.4V two-cell pack. At that point the BMS enters a protection lockout state and the charger sees no load, so charging appears to fail entirely. The fix is a slow pre-charge using a compatible charger that supports recovery mode, or connecting the battery and leaving the instrument on the dock for 30–60 minutes at low current until the BMS re-initialises above 6.0V total.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eMTS-2000 shuts down mid-measurement with no low-battery warning\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis is a voltage sag issue, not a capacity issue. Under sustained OTDR laser firing combined with display and processing load, a degraded or cold cell pack can momentarily drop below the BMS cutoff threshold even when the indicator shows 40–60% remaining. The instrument loses power instantly because the BMS trips on undervoltage, not on capacity. Check cell health by watching the voltage reading in the instrument's diagnostic menu — if voltage under load drops below 6.8V, the pack needs replacing regardless of what the charge indicator shows.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43360677953626,"sku":"BWCS-JDS200SL-1","price":45.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43360677986394,"sku":"BWCS-JDS200SL-2","price":53.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43360678019162,"sku":"BWCS-JDS200SL-3","price":59.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-JDS200SL-1.webp?v=1778616161","url":"https:\/\/batteryweb.com\/products\/jdsu-viavi-mts-2000-replacement-battery-74v-5000mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}