Is the D050S required to use solar panels with the B230 or can you use a 7909-MC4 connection?
After further research the answer is yes, you need the $199 D050S to solar charge the B230 separately. It can’t be charged directly.
Yes. If you want to charge the battery pack with PV, you need an additional adapter D050S. The exact connection is
solar panel–pv charging cable–D050S–battery pack