Are you utilizing solar and AC in your system?
Use any one of the all in one units that tickles your fancy that can do AC charging, and run an inverter of the vehicles 24v system connected to the AC input of your all in one. You set the charge limit on the all in one to be appropriate to the max current you want to draw from the vehicles system.
Going to be relatively inneficient going from DC to AC to DC, but is free power anyways and likely going to be the cheapest and easiest way for high power charging.