As the SAE solar type connection limited charging to 5 amps I finally got around to upgrading the charging port to a standard C14 connector. This allows me to use any standard C13/C14/C15 extension cable from my chargers and to easily make a female connector for any future charger. The C14/C15 port is rated for 10 amps at 240 volts so it should handle 10 amps at 84 volts fine (it does, the SAE connectors become melty when charging at 10 amps as they are only rated for 30 amps at 24v max, or 8 amps at 84 volts).