{"product_id":"metz-9637-replacement-battery-6v-4200mah-ni-mh","title":"Metz 9637 Flash Replacement Battery 6V 4200mAh Ni-MH","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eMetz 9637 \/ 9702 \/ 9704 \/ 9705 Series — 6V Ni-MH Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 6V 4200mAh Ni-MH replacement battery for Metz professional flash units, including the 9637, 9702, 9704, and 9705 models. It slots into the battery compartment where the original Metz cell sits and restores flash operation without modification. Dimensions are 88.95 x 47.55 x 36.50mm — confirm against your existing pack before ordering.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMulti-model flash platform fit:\u003c\/strong\u003e\n    The 9637, 9702, 9704, and 9705 share the same battery bay dimensions and 6V supply rail. The flash capacitor charging circuit draws from this voltage directly, so a correctly rated replacement restores full guide number output without retuning the unit.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through repeated capacitor charge-drain sequences on a Metz flash chassis. The cell held voltage through multiple consecutive full-power pops without triggering a low-voltage cutoff.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle charging on Metz flash units:\u003c\/strong\u003e\n    Ni-MH cells shipped in storage state may read as flat on the flash's charge indicator. Run one full charge in the Metz charger before shooting — the indicator circuit calibrates against a charge curve, not resting voltage, and will read inaccurately until that first full cycle completes.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eFlash output dropping mid-shoot on a fresh Ni-MH cell\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eNi-MH cells deliver voltage that sags under the high instantaneous current the capacitor pulls during recharge. At full guide number, a 9637 flash draws a significant surge from the cell each time the capacitor tops up. If the cell has not been properly conditioned, internal resistance is higher than rated, which amplifies this sag. Run two to three full charge-discharge cycles through the Metz charger and the sag narrows as the cell reaches rated internal resistance.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eFlash recycling time getting longer as the shoot progresses\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eRecycling time is directly tied to how fast the cell can push current into the capacitor circuit. As cell voltage drops through the discharge curve, recharge current to the capacitor decreases and recycle time stretches. This is normal Ni-MH behaviour, not a faulty cell — it happens near the end of a charge cycle when cell voltage falls below roughly 5.4V. Stop shooting, recharge fully, and recycle time returns to the fast end of the spec range.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43333901221978,"sku":"BWCS-NP66-1","price":50.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43333901254746,"sku":"BWCS-NP66-2","price":58.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43333901287514,"sku":"BWCS-NP66-3","price":64.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-NP66_1.webp?v=1778213590","url":"https:\/\/batteryweb.com\/products\/metz-9637-replacement-battery-6v-4200mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}