I have a 3,500 kg three-sided tipper trailer with electric drive. A problem occurs when the trailer is fully loaded and the battery is empty – in this condition the tilt function cannot be used. The battery is installed in a closed battery box under the trailer, which makes it inaccessible from the outside or from the bottom. You can only reach the battery when the trailer (in empty condition) is tilted. I am looking for a way to get started. My idea was to move cables from the plus and minus poles of the battery to a weatherproof socket and to attach them to the frame of the trailer. So I could use the appropriate plug to connect an external starter battery or my car battery and operate the trailer. My questions: What kind of socket, plug and cable are suitable for this purpose? Gi Is there possibly already ready systems or solutions for such cases? Or is there a better way to solve the problem? Thank you in advance for your support!