Motorhome towing trailer electrics for charging Electric bike

Hi all, I have a Peugeot Boxer 2015 2.2 HDI, I have had a tow bar fitted with a 13 pin plug. QUESTION :- How do I wire up a battery in my trailer Sipo I can charge our two electric bikes from Motorhome and solar. Thank you in advance for any help. Happy to pay for a wiring diagram so I can do it myself. Budgie

Can anyone help me or am I in the wrong place to ask this question???

As your chargers probably need 230v, I’d install a 230v socket next to the 13p.