Ever see a EV battery dehumidifier? Looking for advice.

1852 Views 7 Replies 5 Participants Last post by Jimbo69ny, May 4, 2018

Jimbo69ny

Discussion Starter · Apr 28, 2018

Hello,

If you dont know already I am working on a range extended trailer. I am currently using a battery pack from a Tesla Rav4 EV but as soon as I find a P100 kwh pack I am buying it and using that instead. (please let me know if you find one at a reasonable price)

The Rav pack has a dehumidifier. It actually says "dehumidifier" on the part sticker. I need this battery to be weather tight and I need to know more about these valves. I have a hard time believing that they would build anything that would allow water to get into the pack but I need to make sure.

I just uploaded this video so you can see what I am talking about.
https://youtu.be/hIuwL95NntQ

If you have any experience with these please let me know.

Thanks!

Save

1 - 8 of 8 Posts

onegreenev

· #2 · Apr 28, 2018

Posted a thought about this on your youtube video.

Save

Karter2

· #3 · Apr 29, 2018

Jimbo69ny said:
I have a hard time believing that they would build anything that would allow water to get into the pack but I need to make sure.
Thanks!

I have no direct experience with those Tesla packs, but..
1)....I find it hard to believe the pack can be 100% sealed airtight.
2)....The pack will undergo significant temperature changes , both from cell warming, and external ambient conditions
3).... As a result of the above, the pack will" breath" air which will inevitably have a % of water vapour with it.
Hence , it makes sense that they have fitted a system to "manage" that in/out airflow and provide some form of de-humidification. ?
Just a SWAG !

Save

Jimbo69ny

Discussion Starter · #4 · May 2, 2018

Thanks for your input. I thought of a test I can run.
Take the cover off place something underneath, run water over top, see if it comes through the dehumidifier.

Save

Kevin Sharpe

· #5 · May 2, 2018

Maybe they are maintaining a positive air pressure in the pack? Would be useful to apply 12V to that pump and see what happens? Is the external air sucked in through the dehumidifier beads?

The Model S/X packs are not strictly 'airtight' because they have the exhaust valves along both sides. They also don't have any dehumidifier beads. The only feature they do have is a pressure equalisation valve.

Save

Jimbo69ny

Discussion Starter · #6 · May 2, 2018

Kevin Sharpe said:
Maybe they are maintaining a positive air pressure in the pack? Would be useful to apply 12V to that pump and see what happens? Is the external air sucked in through the dehumidifier beads?

The Model S/X packs are not strictly 'airtight' because they have the exhaust valves along both sides. They also don't have any dehumidifier beads. The only feature they do have is a pressure equalisation valve.

Good idea. I should be able to easily send 12 v to the pump to see what happens. I imagine that it would blow air out but Ill see.

Save

wb6otg

· #7 · May 4, 2018

Smart uses a small desiccant cartridge on their battery pack. I haven't looked into the details, but I assume they're expecting a small amount of water vapor to enter either though a pressure equalization valve or because the cooling system isn't 100% vapor tight.

Save

Jimbo69ny

Discussion Starter · #8 · May 4, 2018

I tested the cover. The larger round one is a one way check valve that lets air out but not in. In heavy rain though I am not convinced that rain wont get in so I need to make some kind of cover for when it rains. The other one on top I am not sure about. It looks like a manual bleed valve. I havent taken that one out yet.

Save

1 - 8 of 8 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.

Top Contributors this Month