Enclosure with ventilation for vehicle application

[filippomasoni]

What do you think is a good lightweight DIY design for a battery enclose (mine will be an 8S EVE LF280K configuration) for a truck camper build, that prioritizes ventilation to keep the temperatures cool during trips in warm areas?

I've read so much on this forum and elsewhere about compression and I perfectly understand it, but I think temperature control is as much or more important but nobody talks about it. The EVE LF280K spec sheet for example gives a 6000 cycles life at 25°C with compression and 2500 cycles at 45°C under the same compression.

In a moving vehicle, I definitely need a rigid enclosure that keeps the cells from moving around and the classic threaded rod and plywood is a very effective, simple, and lightweight option since there are fewer sides of plywood than a box, but doesn't allow airflow between the cells. I was thinking of putting alveolar pvc panels between the cells for improved airflow of each cell but I'll lose the compression and won't have a rigid block of cells.
Will a fan blowing air over the terminals (which are probably going to be the warmest spot and also probably thermally conductive to the inside as well) be enough?

What are your thoughts?

 

[S Davis]

Mount them above the bottom of your enclosure and circulate air around them, then either heat or ventilate the enclosure.

 

[filippomasoni]

Thanks, I didn't think about circulating air even below the cells. Those 4 "feet" I see in the image are where the plywood sides are resting? Are those like rubber bushings for vibrations? I'm interested to learn more about this setup, really intriguing.

 

[S Davis]

Thanks, I didn't think about circulating air even below the cells. Those 4 "feet" I see in the image are where the plywood sides are resting? Are those like rubber bushings for vibrations? I'm interested to learn more about this setup, really intriguing.

Yes I added another picture, they are 1” vibration mounts.

 

[filippomasoni]

Really cool setup, with spring compression as well.
Are vibrations really an issue? I assume the worst-case scenario would be of a long washboard road.
What do you have at the bottom of the cells to spread the heat generated from the heat pad I see in the first picture.

 

[HRTKD]

My eight 280 Ah cells are in 4s compression fixtures that are made up of the typical plywood ends with threaded rod and no spacers between the cells. The long sides of my batteries have warming pads permanently attached. At this time I have no forced air circulation. All "cooling" is passive.

My bumper pull toy hauler trailer goes down some very rough roads. I'm more concerned about vibration than temperatures. So far, I've had no issues with battery temperatures. I've camped in the low 90°F's.

 

[S Davis]

Really cool setup, with spring compression as well.
Are vibrations really an issue? I assume the worst-case scenario would be of a long washboard road.
What do you have at the bottom of the cells to spread the heat generated from the heat pad I see in the first picture.

The fan blows down and across the heat pad circulating and heating the air around the batteries.

 

[filippomasoni]

Mount them above the bottom of your enclosure and circulate air around them, then either heat or ventilate the enclosure.

I'm resuming this old post because I have a further question: Do you have anything supporting the cells on the bottom of the compression rig? Or are they directly resting on what looks like an aluminum plate in the photo?

I really like your setup, we discussed it on a different thread as well, and I'm trying to design something similar in my build. As that's a very heavy load for my camper I was thinking of placing it closer to the cab and having the two water tanks on each side, this way I have the best weight balance. But I want the cells to be suspended a bit from the floor so that in case of any leaks or flooding in the camper they don't short out. Hopefully, it will never happen, but better safe than sorry. You also have the enclosure on the outside that can be sealed, but I feel like that adds unnecessary weight and I'm looking for something alternative.