Recently, I have fitted an Anderson plug to the batteries so that I can connect external power.
The 50 amp plug, I ordered in China through AliExpress, 4 pieces for € 24.65, good quality. In addition, I have ordered dust covers, € 4.35 for two pieces.
Soldering together of the plugs is quite easy, for example, see this video:
For the wire I used an old jumper cable.
This is how it is mounted on the battery box (also made new, but that is described elsewhere)
I use the connection primarily to connect my compressor
