I did a little looking and found these. https://www.amazon.com/BTF-LIGHTING-Plastics-Waterproof-connctor-Applicable/dp/B01D2I9818/ref=asc_df_B01D2I9818/?tag=hyprod-20&linkCode=df0&hvadid=167146990738&hvpos=&hvnetw=g&hvrand=12984674793738423213&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9025512&hvtargid=pla-366202600037&psc=1
They are barrel type screw on connectors with o-rings to keep out water. Available in 2, 3, 4 and 5 wire connectors. Just snip off the JST connectors and then solder/shrink wrap the connections.