Anyone attempt to install an aadditional battery in a P400? Looks like there may be enough space in the passenger side front corner of the engine compartment. Havent attempted yet, but just received a dometic fridge, and the thought of also putting a battery in the rear cargo area just seems like a waste to me.

If no one has attempted, consider this a place to see if it can be done.

 

Why not under the floor in the rear cargo area? Thats where I put mine (p300). The cable from main battery to that compartment is only about 6ft. This also puts the aux battery very close to the fridge. There is less room under the floor on the p400, but I have seen a couple people that have put an aux battery next to the suspension compressor in the p400.

 

Third row seat is the issue for me. When we're eventually out of covid times, we'll be transporting a full truck around, so had to have it.

 

Gotcha. I originally looked at that space under the hood for an air compressor. Battery connections are easy with the jump start points. Finding some solid mounting points will be the tricky part. My 100a is 60 pounds. Lithium would be good for the weight, but I'm not sure how they handle the heat in the engine bay. Lithium batteries i've seen recommend no more than 140-150f.

 

Yeah, you're right. Lithium is like 140F max. Looks like lead acid is the best, but weighs a ton. Likely to need to fab some sort of bracket(s).

Given the desire to maximize rear cargo space, make the Dometic hot swap-outable and plug-in ready, I think the engine compartment is the best bet. Might need to figure out some sort of ventable box for the battery.