I added a house battery bank with 3x 16Ah LifePo4 batteries, a 400watt inverter, A Steca 8A solar MPPT charger into my truck. I snuck them behind the rear quarter interior panel where the (2nd) factory DVD player was. They ended up fitting perfectly in the cavity and I made a little battery box from some aluminum angle. In total these will give me about 615 watt-hours or 48 Ah of total house battery capacity. Not a huge amount, but enough to charge my drone, a laptop or two, run my fridge, and power any LED lights but most importantly will run an electric blanket all night! I probably won't use the solar input much if at all but since I had it I wired it in anyway. The battery bank can always be expanded if I figure a clever place to hide more batteries.
Miady batteries:
https://amzn.to/3cITEjL These batteries have build in BMS that manages cells, have over and under voltage protection, thermal protection, over current protection, charge protection, etc, etc. So basically I can just hook them all up together in parallel and forget about em! Also used a little fuse block to keep the wiring tidy.
Added dynamat to the inside fender to block some noise since I'm opening this area up a little but also to prevent dents if the batteries move a little bit.
I have not set up the connection to the vehicle alternator yet, waiting on the DC-DC smart charger.
I also took inspiration from
@DanielChase and cut up an old foam camping pad and hid it under the carpet. Hopefully it will level out the lumpiness from the seat mounting brackets and be a bit more comfortable. I added these D-ring tie downs also to better hold my gear:
https://amzn.to/2HpA7Jg