Soo.... bit long winded of a post, but...
I was able to get a hold of a 85Ah Odessey 27f AGM 925CCA. while not my first choice (had ordered a X2 power/Northstar 27f 92Ah 1230CCA AGM - but due to timing, and shipping issues was not going to arrive in time for my trip). So I used the stock 24f tray, you can use a pair of sheers/blade to cut the corners of the tray, and either bend the sides down.. or cut them off with a rotary tool. I then ran a 25ft piece of 4Ga. battery cable sheethed in 1/2" plastic loom (for abrasion protection) I ran this fromt he battery to a 50A inline breaker, then over the engine along the factory wiring harness, and then down along the firewall on the passenger side, and back towards the bed along the factory tail gate & aftermarket pop-lock wiring loom, zip tying every foot or so, I then lead it up into the bedside, and removed the small cubby/inverter outlet by removing the 6 torq screws. I drilled a 1/2"hole in the small cubby, and ran the wire through. I then crimped on a copper lug, and shrink wrap on it.. zip tied the cable to the wiring harness (made a loop with eh foot or so of slack it had (used all 25ft). I then screwed in a 4 circuit fuze box from bluesea systems with dust cover in the back of the cubby, I then drilled a 1/2" hole at the top of the cubby box, and ran wires through to a dual port 12v oultlet, and dual USB 4.8A rated plug with rubber covers (bought from marine supply, so should do well in bedside of my truck in light rain, I do run a tonneau cover) the fridge, and the USB are on separate circuits, and I have 2 spare circuits for my diesel heater, and other 12v items if I need them.
3 day trip to NMW (north maine woods) - my system worked great. we went grocery shopping on wednesday night, got all our supplies, and I had the fridge pre-cooling while we were shopping. went home, and removed the baskets, and packed everything pretty tightly. I was running the fridge at 38*, and the freezer at 3* F. I placed all our food intot he fridge, and I checked it in the morning, even with the tonneau cover closed it held good temps. I made sure to leave spacing betweent eh bed-side, and the exhaust ports of the fridge, and the back of the tailgate. I checked on the fridge at every stop we made (downfall of the iceco system is no bluetooth/wifi ( i supposed I could get a device/alarm for it...) I did find on my second night of camping I accidentally bumped loose/unplugged the 12v (looking at an aviation plug to solve this) when setting up camp (removing items from the bed.. it was disconnected for about 4 hours or so, but the insulation was sufficient.. my ice cream did not melt, just got soft.. temps raised to about 45* in the fridge, and 15* in the freezer... apply power, and within 10 minutes it was back to temps.. average temps on our trek were around 60* at night, and as high as 90* during the daytime
in all my checks on the fridge I always was around 12.4-12.6v when the compressor was idle.. and when running the fridge was reading roughly 11.8v. I saw voltage ont eh readout go as low as 11.4 (with the vehicle off - I assume a lot of this is due to the voltage loss/drop on the 25ft of 4ga cable, and 2ft of 10guage from the fuze block. I had a jumper pack with me, but never once did the truck not want to start. I have not yet done the OVtune tweek/tune, so the AGM is only receiving approx 14.4v, when the AGM likes to see upwards of 14.8v I do eventually plan to run the OVtune/KDMax tune with AGM charge parameters.... for now I will simply hook it up to a smart de-sulfating charger every week or so (& before any trips) until i get it programmed..
we would typically arrive at our campsites around 5-7pm (trying to avoid the blackfly swarms here in Maine..) and setup camp.. teardown, and leave time from camp was around 9-10AM so easily 14-17 hours from engine off, to restarting the engine...
if anyone has any questions let me know.