Insulating the subwoofer cavity for a LiFePo4 battery

[joshik]

So I tore out my subwoofer to make room for a 50ah lithium battery for a secondary battery system to run my camp lights, chargers and a few other things. I've been thinking about how to keep that area cool. Today was a nice day in San Diego but of course direct heat on a car even on a cool day can lead to high temps in a car, and even hotter inside the body cavity. I'm trying to think of a way to effectively insulate and also possibly actively cool this area...

Today, I had my temp probe in the cavity with the subwoof panel closed and it got to 103F. No real insulation at the moment besides a few sheets of sound deadening that I had lying around.

I'm not actively charging the battery at the moment. I have my OEM amp still there to power the rest of my speakers but once I get a chance to rewire/bypass the amp, i will remove it and put in a DC-DC/MPPT charger (renogy) in there to keep my house battery topped off.

I ordered some PC fans and a temp sensor/controller to see if that could help by piping in air from the car but not sure how much that would help since it would be hot in the car anyways.

 

[originalg00kster]

Damn thats tight clearance. I would def try to get some airflow in there somehow.

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[joshik]

Damn thats tight clearance. I would def try to get some airflow in there somehow.

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yeh super tight. I might swap out to the chinese 3.2v (x4) cells which is a smaller form factor and will give some more space for airflow.

 

[MikeinNH67]

I think I would try something like Dynamat on the inner sheet metal and see what that does for the temp. Of course you could always measure the difference between the car parked with that side not getting sun opposed to it getting sun. Not sure what more you can do unless you pull colder air from outside the car. Interesting setup.

 

[djjazzyjoel]

So I tore out my subwoofer to make room for a 50ah lithium battery for a secondary battery system to run my camp lights, chargers and a few other things. I've been thinking about how to keep that area cool. Today was a nice day in San Diego but of course direct heat on a car even on a cool day can lead to high temps in a car, and even hotter inside the body cavity. I'm trying to think of a way to effectively insulate and also possibly actively cool this area...

Hey Joshik, just curious how this setup has been working for you? This is about the best idea I've seen to avoid spending a bunch of money on a battery tray for the engine bay. Is your LFP a mini? I've seen several of these minis and feel like they open up some additional options for locations.

Thanks!