Cooling the Leaf Battery with Ice, This Actually Works?!?

[Gusset]

Just seeing this thread for the first time…interesting stuff, I enjoy experimentation!

I’m wondering if ice poured in through the back seat access could have a detrimental effect, though. It basically cools a portion of the top of the battery pack, and depends on heat transfer mechanisms that the pack may not be designed around to cool everywhere else.

Could ice-on-top lead to a significant temperature difference in cell temps over the pack, as in cooler cells on top and significantly warmer cells on the bottom or at the corners, that isn't noticed by the sensors? Could it fool the system into charging cells in the lower half of the pack at a higher rate than is appropriate for their _actual_ temperature?

 

[xboxice]

Well that knocks that on the head

Yeah that's why i didn't think to do it, don't wat rust

 

[Bombastinator2]

Just seeing this thread for the first time…interesting stuff, I enjoy experimentation!

I’m wondering if ice poured in through the back seat access could have a detrimental effect, though. It basically cools a portion of the top of the battery pack, and depends on heat transfer mechanisms that the pack may not be designed around to cool everywhere else.

Could ice-on-top lead to a significant temperature difference in cell temps over the pack, as in cooler cells on top and significantly warmer cells on the bottom or at the corners, that isn't noticed by the sensors? Could it fool the system into charging cells in the lower half of the pack at a higher rate than is appropriate for their _actual_ temperature?

The detrimental effect appears to be rust. The steel top plate would act as something of an integral heat spreader like on CPUs. One coup perhaps use heat pipes like on CPUs. Not sure how effective it would be.. theres a limit to how many joules/sec such things can move *waits for someone to do a finned aluminum battery top plate so they can drag their leaf. An electric car with exhaust…liquid water*

 

[DougWantsALeaf]

Yeah that's why i didn't think to do it, don't wat rust

It's why I used sealed ice packs. you get a little condensation on the ice pack, but that evaporated quickly.

 

[DougWantsALeaf]

The detrimental effect appears to be rust. The steel top plate would act as something of an integral heat spreader like on CPUs. One coup perhaps use heat pipes like on CPUs. Not sure how effective it would be.. theres a limit to how many joules/sec such things can move *waits for someone to do a finned aluminum battery top plate so they can drag their leaf. An electric car with exhaust…liquid water*

It looks like we have enough data points to suggest a modest cooling effect. I am excited to see if a cool or winter run would allow for more equal cooling g of the battery, maybe allowing a 2nd or 3nd DC.charge st full bore, vs the 55-60ish KW you see when cell temps vary significantly.

 

[Bombastinator2]

It looks like we have enough data points to suggest a modest cooling effect. I am excited to see if a cool or winter run would allow for more equal cooling g of the battery, maybe allowing a 2nd or 3nd DC.charge st full bore, vs the 55-60ish KW you see when cell temps vary significantly.

There is the problem that it cools too much, or cools some control component too much, or something. I don’t know which. Something under the car gets cold in severe winter freeway driving and cause drastic temporary range reduction

 

[knightmb]

The battery cases definitely rust, I have seen one rust right through and let water In

I'm curious then how this works in rainy conditions? I've driven around in the rain, checked under the cap and it was all wet and was like that for days until the rain stopped and there was time for it to air dry. Shouldn't everyone, especially in the wetter parts of the US or world have the same issue?

 

[xboxice]

I'm curious then how this works in rainy conditions? I've driven around in the rain, checked under the cap and it was all wet and was like that for days until the rain stopped and there was time for it to air dry. Shouldn't everyone, especially in the wetter parts of the US or world have the same issue?

Great point ill check mine and see after a good dose of rain.

 

[DougWantsALeaf]

I can't believe a little moisture rusts the case out as it's not air/water tight (above the case).

 

[Bombastinator2]

I can't believe a little moisture rusts the case out as it's not air/water tight (above the case).

I can. Gravity is a thing and oxidation happens in atmospheres containing oxygen. Being water tight isn’t hard though. Unless your hood is messed up you’re fine.