** Fluence Energy's shares down 8.8% at $16.90 post-market as it looks to raise capital ** Renewable energy storage provider announces $300 mln offering of convertible bonds (CBs) due Jun 2030 (6.5 year tenor)

** Arlington, Virginia-based firm plans to use portion of net proceeds to fund capped calls, remainder to purchase intercompany convertible note for working capital, upgrade one of its battery cell production lines

** FLNC shares on Mon closed up 9.5% at $18.52, giving co ~$3.4x bln market cap, per LSEG

** Stock has lost 10% over the past month, and is down 22% YTD

(Lance Tupper is a Reuters market analyst. The views expressed are his own)) ((lance.tupper@tr.com 1-646-279-6380))