The smaller Victron marine
chargers come with an output wire on the DC side with a blue plug
. Victron supply two possible means of connection to the battery with the charger: ring terminals and clamps (see photo).
I presume these connections have been lost
. I suspect you could order these as an accessory or a spare part, or find the same plug
on ebay etc, but it would much simpler to cut off the connection and join some wires to connect to your batteries
with ring terminals. Don’t forget a fuse.
The only thing to watch is these chargers, like most, have a parasitic draw when connected to the batteries
, but not plugged into the mains. The draw is very small and most people do not worry about these small power losses, but they do add up over many devices. If you follow my suggestion above, you will no longer be able to unplug the charger on the DC side and remove this small load, but you could install a switch or just remove the fuse when the charger is not used for long periods.