I have an Alco/Ritar AGM second battery under the passenger seat box with 300TDI fuses in their original position. I use ratchet straps to secure the batteries down and have heavy rubber matting between the tops of the terminals and the top panel. 
 
It's tight, but can be done. Sorry, away from my vehicle so can't get you pics.
				
			 
			
		 
			
				
			
			
				'95 110 300TDI, F&R ARB Lockers, Twine Shower, Aux Sill Tank, Snorkel, Cargo barrier, 9 seats, swingaway wheel carrier, MadMan EMS2 
'85 110 Isuzu NA 4BE1 3.6l Diesel, 0.996 LT-95, Rear Maxi (SOLD)
'76 SIII 109" Nissan ED33 5-SP Nissan GBox (SOLD)
			
			
		 
	
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