Cooling battery packs

Headrc

Headrc

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Jan 27, 2018
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Hi, another newbie on this forum. I have a question regarding the cost ofcooling of builds. I believe everyone here has a good handle on what the whole harvesting of cells and building packs cost. But what about cooling? What are the different approaches and costs attached to them? Or is it not a concern meaning no cooling really required? Thanks for a great source of information here. RH
 
It really all depends on your application. My setup does not heat up at all at my mx draw which is about .2A per cell. But if you have a high drain the cells will get hot and the simplest way is just a fan blowing across the cells. I have read of people using mineral oil as a coolant and submerging the entire pack (or PC motherboard) in it and running a pump and radiator. uit all depends on your specific application and needs
 
Yes I figured that, hoping to get more feedback here. If the majority answer the current draw does not warrant a concern on cooling then that certainly answers the question. Thanks for responding.
 
Headrc said:
Yes I figured that, hoping to get more feedback here. If the majority answer the current draw does not warrant a concern on cooling then that certainly answers the question. Thanks for responding.
Click to expand...

This is it exactly. The current draw is so low that heat isn't a factor. Normally. Now, there are times that there is heat generation. This is usually at the connections, and not the cells, though. As Pete (HBPowerwalls) showed in his video update, he had a connector that wasn't fully crimped and was creating almost 15-20C higher temps at that connection than any other connection. So, it's pretty much a safe bet that you won't need cooling in most conditions.

With that said, if you live in a climate where the ambient air gets above 40C(110F), you'd want to add secondary cooling to help keep them from over heating under normal conditions.
 
Thanks Korishan ...two replies stating it is not a concern so far!
 
It is a concern if you dont know what you are doing. If you know how they work and how you load them that wont be an issue.

If you get that much heat of the cells that you need to cool them in a powerwall you might have huge issues. On cars and Ebikes is another thing.
Personally i think that you should never push the cells that high that they ever produce heat in a powerwall :) If you do that they wont last long enough to be worth it :)
 
If I may ask another, but related, question: I am looking for ways to better insulate the packs electrically to avoid shorts and blown fuses. That just seems a lot of exposed metal. I figured I could use jumbo heat shrink, like the e-bike people sometimes do, but was also concerned about the shrink trapping in the heat from the battery packs. I'm in the USA south and heat can be an issue in summer. Anyone have thoughts: would using heat shrink on each battery pack cause more problems that it solves?

Mark

edit: Note, my application is a powerwall drawing only moderate current.
 
You could rig up a series of Peltier coolers and fans to vent the heat outside and blow the cold air over the battery packs. Perhaps configure it only for higher draw days or very hot ambient conditions.

Just search Amazon or youtube for Peltier coolers, neat devices and can be run on your solar without pressurized refrigerant.
 
Peltiers would draw way to much power to worth anything in this type of application. Would be better to run a small A/C unit into an enclosed cabinet/room.

The easiest thing you could do is take a piece of cardboard or thin wood paneling and tape, strap, bolt/screw them to either side of the pack. That way if you need to get back into it for some reason, you aren't really doing much damage or need to replace parts with new stuff.
Personally, I think a pack should be fine out in the open. The only place you really need to be careful is at the main connection points. Pete (HBPowerwalls) has experience in that department. So does Daniel (DIY Tech & Repairs, Daromer; altho his was more going up a ladder at the time).
 
:)

Yes for open areans just design slots where you have the banks. No use of putting big fat heatshrink around it capsulating the heat if you ask me.
 
The message is getting through here ...design your wall properly! But even so, if you wanted to be extra careful what about phase change material? Any ideas on that?
 
Headrc said:
what about phase change material?
Click to expand...

??? What are you talking about?
 
Cool stuff.... ;)

It are different materials that change state, liquid to solid or other way around at a specific temperature.
On this change of state point, it can absorb a lot of heat.
A kind of salt is used in big solar plants to store heat to run the turbines at night... (salt changes to a liquid and back)

Water works also, it takes more energy to cool at the 0C point to build ice then cool ie from 10C to 1C.
If you find a material that changes state at 40C it will keep the batteries a long time on this temperature, when the batteries cool down it changes state again.

Interesting, but not practical for batteries i beleave.

https://www.google.be/url?sa=t&rct=...nge_material&usg=AOvVaw2VKDuZS87JDgWQEaCqryx1
 
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