We have on the 244rbs, we are using 2 off 110AH 12V AGM. Mounted under the seats over the axles.
Seemed a sensible place, heavy stuff over the axles.
We also carry another 2 batteries the same in the Jeep feed by 400 watt solar panels on the travel trailers roof.
244RBS Funfinder 2012
Jeep Grand Cherokee 3 ltr CRD