Rack Mounted Battery enclosure to vent failed cells

[automatikdonn]

I think in light of recent news about the explosion in Germany, having a discussion on risk mitigation methods is prudent.

I think designing an enclosure that goes around the battery packs that would vent directly outside is worth discussing.

My initial thoughts are to make a direct vent system that would suck air in from outside and vent air outside. There are some challenges with this method due to outside temperatures. I am wondering what we can come up with as a community to mitigate this risk.

 

[Bluedog225]

That would be easier than venting the whole space.

The rack will make this easier as it can be used as a frame.

My initial thought is to build a simple box out of fire guard sheetrock. Maybe double layer.

The unfortunate part is that it has to be top and bottom vented. Will make it more difficult as a hole in top of my conex needed. Maybe I can use one of the pressure equalization vents.

 

[automatikdonn]

That would be easier than venting the whole space.

The rack will make this easier as it can be used as a frame.

My initial thought is to build a simple box out of fire guard sheetrock. Maybe double layer.

The unfortunate part is that it has to be top and bottom vented. Will make it more difficult as a hole in top of my conex needed. Maybe I can use one of the pressure equalization vents.

I agree, an enclosure will lead to a more predicable result.
Anything that will trap and move dangerous gases to the outside is worth the conversation to protect against this failure mode. The biggest question is how can we also not freeze our batteries when it's 0 outside? Do we have a detector in system (and then of course how reliable are they) - how can we make it work...

I am a big fan of engineering challenges, so this should be fun if nothing else.

 

[cs1234]

Unless the battery case is airtight and you are bringing in air from the outside, and ducting that same air out, aren't you losing room air regardless?

Does it make any difference air exchange wise if you just vent the whole room vs a shrouded battery? Maybe some of our air conditioning folks on here can weigh in.

EDIT, can use a smaller exhaust fan if you duct the batteries I suppose.

 

[automatikdonn]

Unless the battery case is airtight and you are bringing in air from the outside, and ducting that same air out, aren't you losing room air regardless?

Does it make any difference air exchange wise if you just vent the whole room vs a shrouded battery? Maybe some of our air conditioning folks on here can weigh in.

EDIT, can use a smaller exhaust fan if you duct the batteries I suppose.

I think it's mostly about air exchange rates. One of my stacks of batteries sit in a 3k sqft shop, so I am not sure that venting the whole room is a great idea. We are just trying to prevent the buildup of the gases to dangerous levels. I would think we would have many things to consider for it to preform properly.

My other battery stack is in the garage which is directly connected to the house - rather not have my whole garage be 12 degrees if I don't have to.

I have no answers, only questions and ideas.

 

[cs1234]

I think it's mostly about air exchange rates. One of my stacks of batteries sit in a 3k sqft shop, so I am not sure that venting the whole room is a great idea.
My other battery stack is in the garage which is directly connected to the house - rather not have my whole garage be 12 degrees if I don't have to.

I have no answers, only questions and ideas.

Yes, in a 3k sqft shop, venting the whole room would be more challenging / resource intensive.

 

[automatikdonn]

I am thinking I might start with this ductboard. Any reason not to use this material?

Master Flow 48 in. x 120 in. Duct Board - R-6 DBOARD1 - The Home Depot

The Master Flow 48 in. x 120 in. Duct Board - R-6 features fiberglass construction with an FSK backing for sturdiness over time. Cut this duct board to size and use it to build your own HVAC fittings or trunk duct, and then assemble it with fiberglass weave and mastic or duct-board-approved duct...

www.homedepot.com

Maybe these fans for intake and exhaust.

https://www.amazon.com/AC-Infinity-AC-Powered-Playstation-Component/dp/B01MZ6T8VF

And then maybe just 3d print a couple of these things. (probably need to design something to better for the ductboard.

120mm Fan to 100mm A/C Duct Adaptor by MCroucher

An adaptor/reducer for a 120mm case fan to a 100mm diameter air conditioning duct. Used on my fume cabinet for my RepRap Prusa Mendel. (Short description: http://www.youtube.com/watch?v=YKh6kgO77Us) The A/C ducting is standard 100mm ducting, as used in range hoods and bathroom extraction fans...

www.thingiverse.com

 

[Bluedog225]

I think the venting needs be passive. Fans fail. Electricity fails.

I’d treat it like a lead acid battery compartment. Has to be vented at the top and bottom to allow passive air flow.