looking at the standalone panels which come with one of these…
Maybe one of these 🤣 but overkill though, a straight whatever you have to - IIRC - xc90 should work, avoid paring those panels with your existing ones and - if it’s available - use the alternate input. https://www.amazon.com/Universal-Connector-Anderson-Extension-Compatable/dp/B0CF5B87SV/ref=mp_s_a_1_3_maf_2?crid=AOKREFHIWT2K&dib=eyJ2IjoiMSJ9.0fIgB_kmus3xGUNXeWbOOv2qq5S5TXJp6brwK6S5pJAlFncYH-yupDIVUkVtAhwVcI3zc2As8gAvKXA1l8zaDrtNGn2yVT1_jOoJYr8QEmj9G4QvL6rv32zmhdSWiFtSGl62oarNhV4QTY-ota5xAeuI7KjJ6LJ-noiQvv9aEezlBIrPC4MIm4DEo49Z-w7qj2ZVIRwUfnLSdvFQRa09TQ.amJDTKOMue-E2HnmXRzjLBVNgSy0s7u-OuBUMZsJVk0&dib_tag=se&keywords=4-in-1%2Bsolar%2Bextension%2Bcable(solar%2Bto%2BXT60%2FDC5521%2FDC7909%2FANDERSON)%2C&qid=1746267112&sprefix=4-in-1%2Bsolar%2Bextension%2Bcable%2Bsolar%2Bto%2Bxt60%2Fdc5521%2Fdc7909%2Fanderson%2B%2C%2Caps%2C371&sr=8-3&th=1&psc=1