Protecting cells from damp air.

chuckp

chuckp

Member
Joined
Jul 29, 2018
Messages
415
Hi guys

This may not be an issue for concern too many of you in warmer, dryer climates.

I'm interested in what you guys do or have considered as a good moisture protection for your cell packs once they are built and in service.

In my part of the UK it's pretty much non stop rain most of the time. And added to this living very close the the sea I also need to contend with damp salt air that tends to rot out anything metal that's outdoors in next to no time.

My powerwall is in a shallow concrete block built battery house, has a plyboard roof covered with bitumen backed torch on roofing felt. https://secondlifestorage.com/showthread.php?tid=5933

It is dry, keeps the rain out and I don't have any problems at the moment. But I have concerns with damp salt air potentially causing corrosion issuses. Has this been a concern for anyone else?

Have any of you considered using a spray on insulation? Maybe something like this liquid tape.

https://www.amazon.co.uk/Insulating...rproof+electrical+spray&qid=1570438002&sr=8-1

Would it be suitable to coat the entire pack once assembled and mounted including the busbars, fuses, Anderson connectors etc.
Basically everywhere the damp salt air could potentially cause corrosion or verdigris on copper busbars, terminals etc.
 
It's likely a little late now, but ideally you should have insulated your external enclosure - including a vapour barrier, using the same construction methods seen in timber framed buildings - so effectively airtight. At some point soon you'll be pondering how to protect your cells from the harmful effects of charging at low temperatures - solve that issue and you'll not have any moisture concerns.
 
When I had my packs out in the weather (covered but not sealed) I used Vaseline on all the metal areas to keep them from oxidizing. Worked a great. I got a big tub of it (unscented ) and a brush and lathered that stuff on..

Now this summer i put my power wall (camp wall) in a pelican Case and it's sealed up and with the amount of solar I have and Draw it never gets warm
 
jdeadman said:
When I had my packs out in the weather (covered but not sealed) I used Vaseline on all the metal areas to keep them from oxidizing. Worked a great. I got a big tub of it (unscented ) and a brush and lathered that stuff on..
Click to expand...

That sounds like it would create a big mess? Also, you can't get it on every single surface, such as under the positive terminal...
 
Yes it was but it was necessary. I did work but when it came time to change it, it sucked. but it did work. I missed a spot and it was evident it was needed. Which is why I went to a sealed box
 
The wall at the back is the side of the house. I have left space at the sides and front for fitting Kingspan insulation i just haven't got to fitting it yet, I'm hoping for a break in the wet weather when I'm home to get out there and do it.
 
chuckp said:
I'm hoping for a break in the wet weather when I'm home to get out there and do it.
Click to expand...

Haha, you make me laugh, chuck. :p you're in the uk ;)
 
Korishan said:
Haha, you make me laugh, chuck. :p you're in the uk ;)
Click to expand...

Yeah good Ol' Blighty, rains all the time. Apparently this summer was a very good one, I missed it, I think I was putting the kettle on at the time. :p
 
I havent put much thought into it as I am in a warm / dry area, but I guess I would consider insulating an enclosure. The vapor barrier was a good suggestion as well, didnt think of that one.

As to the Vaseline comment, I personally would change that to a non-conductive dielectric grease. That said, if my pack was going to come into regular contact with water or moisture, I would consider encasing the entire thing in a potting compound for electronics.
 
CrimpDaddy said:
The vapor barrier was a good suggestion as well, didnt think of that one.
Click to expand...

I hadn't thought of a vapour barrier either, so that's a great suggestion. I'll defiantly add one before putting up the Kingspan. I have enough Kingspan insulation for the sides, roof and doors.
The back boards against the house have been fixed in place with expanding stick and foam not a perfect insulation but better than nothing.
I have also seen a small 50W greenhouse heater that I could use wired through a frost stat should it ever be needed.
I know it would put more load on my batteries but 50W for the few mins it would be on to take the chill off the air wouldn't be that much.
 
Not insulating the existing house wall, to which your battery board is affixed will negate the effectiveness of any other insulation you do fit - the house wall willlikely be a cavity wall, so will be at external ambient, will form a cold and moisture bridgeto the outside of your enclosure and will form a significant thermal mass that will make keeping the enclosure at a safe charging temperature energy inefficient.

The concept is to form an insulated, airtightbox - within which your batteries our housed - the larger leaf pack that I post images of here occasionally is totally enclosed within a 100mm of XPS, the cooling vents from the inverters are fed to the inside of the enclosure, which is also mechanically vented, along with a couple of 80w tubular frost protection heater.

The frosty nights are getting closer.
 
Almost need to look into some sort of Sealing Hear shrink wrap ??? Thinking the automotive double walled with the glue. Only issue would be excess heat if the packs were used hard. but in a powerwall they usually are not
 
Sean said:
Not insulating the existing house wall, to which your battery board is affixed will negate the effectiveness of any other insulation you do fit - the house wall willlikely be a cavity wall, so will be at external ambient, will form a cold and moisture bridgeto the outside of your enclosure and will form a significant thermal mass that will make keeping the enclosure at a safe charging temperature energy inefficient.

The concept is to form an insulated, airtightbox - within which your batteries our housed - the larger leaf pack that I post images of here occasionally is totally enclosed within a 100mm of XPS, the cooling vents from the inverters are fed to the inside of the enclosure, which is also mechanically vented, along with a couple of 80w tubular frost protection heater.

The frosty nights are getting closer.
Click to expand...

To be honest I can drop the whole Powerwall and put it back up in an hour or so, that is weather permiting.
Insulating the back wall wouldn't be that much of an issue.
If I leave the original plyboard up and insulate over the top of it before putting up two new boards to mount the powerwall, I could probably do the whole job in three to four hours.I

All I need is a dry day to get out there and do it.
 
I insulate my outhouse all across the sides with rock wool and tarp on the outside as a moisture barrier. Picked rockwool over fiberglass just because it handles moisture better. Does have a higher temp rating but I doubt if it catches on fire it's going to do much. My design has the inverter in the enclosure so it's generating a minimum 50W of heat at all times. During the winter months I have a 150W heater attached to a temp controller that kicks in at 45F(7C). It has went through a couple of 0F(-17C) nights without any issues.

Below shows the studs but unfortunately I don't have one with the rockwook in it, just standard 16" studs so the rockwool goes between the studs.
https://secondlifestorage.com/showthread.php?tid=4229&pid=34507#pid34507

Heater
https://www.amazon.com/Lasko-100-MyHeat-Personal-Heater/dp/B003XDTWN2

Something like this for temp controller but I could have sworn i spent only $20 for it.
https://www.amazon.com/WILLHI-Temperature-Controller-22?-572?110V-Programmable/dp/B07M7TSG5W
 
Xps insulation is a very good way to go, better than rockwool.
Rockwool is nice if you can build it in a air tight and dry compartment.
It ismore for noise insulation/reduction for inside.

In your situation you can use spray foam, but its very expensive, and you can not master the technique for one wall.

In your situation i would go with xps or pir sheets. (unilin utherm kingspan, bouwdipir recticel ekotherm to name a few)
xps in 3 cm or pir sheets in 4 cm.
Dont forget your floor and ceiling!
In your situation i would not recommend: glas, fiber, natural,rock wool or regular styrofoam(eps) sheets
Use fm330 or fm350 flex foam to seal up some gaps and holes.
Use uniflex https://www.kroon.nl/image/cache/data/340570-500x500.jpg to secure the insulation to your wall
Your entrance must be air tight also, quickly solved with rubber strips.
https://www.stiho.nl/INTERSHOP/stat...ihoGroep/nl_NL/ProductAfbeelding/M/186544.jpg

for the last thing i would do is a dehumidifier to keep the humidity below 65%

Regarding the wheater, yes the last couple of weeks was very extreme wet

@not2bme,
Rockwool vents moisture better when it was wet, glasfiber take up to 7 years to dry when was wet.
Both have very good fire resisting properties.
Glas around 1700c and rockwool somewhere in the 2200c.
 
I've got a few sheets of Kingspan Celotex that I'm going to use.
I will need to pick up a couple of extra sheets for the back of the doors.

All I need now is a dry day when I'm home.
 
Little update.

Had a break in the rainy weather, managed to drop the powerwall and insulate the back wall.

Fitted 100mm of Recticel PIR insulation boards and mounted the wall in a couple of hours before the rain started again.

It's supposed to be a dry day tomorrow so hopefully will be able to get back out there to do the top, bottom and sides. For the time being I'll wedge the front insulation boards in front of the battery until I have time to fit the proper doors. At the moment its just temporarily boarded over.

I've also got a low wattage tube heater coming on Monday that I'll fit in wired via a frost stat for just in case it gets to cold.


image_nftgst.jpg
 
I'm surprised no one mentioned WD40 (Water Displacement formula 40). After all, that is why it was created. It was to keep Atlas missiles from rusting in their silos.
 
You must log in or register to reply here.
Back
Top