# [EVDL] Recommendations for Li-ion Cooling



## EVDL List (Jul 27, 2007)

> [email protected] wrote:
> > If you read my post from yesterday, you know that my cells are heating up
> > to 55-degrees C in 35-degree C ambient air. Anyone have recommendations on
> > how to cool a pack of 35 200Ah cells? I'm thinking maybe I need to
> ...


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## EVDL List (Jul 27, 2007)

I like the tubing idea, in the summer run it through a radiator, in the
winter through the heater. Heater being the factory hot water heater using a
heat element in a small tank. Controlled by a temp sensor in the battery
compartment. OH and don't use copper, there are plenty of plastics used for
hot water heat/cooling available and won't corrode. 

Mark Grasser
Eliot, ME

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Josh Wyatt
Sent: Monday, August 25, 2008 8:18 PM
To: [email protected]; Electric Vehicle Discussion List
Subject: Re: [EVDL] Recommendations for Li-ion Cooling



> [email protected] wrote:
> > If you read my post from yesterday, you know that my cells are heating up
> > to 55-degrees C in 35-degree C ambient air. Anyone have recommendations
> on
> ...


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## EVDL List (Jul 27, 2007)

There are multiple channels that run along the edges of each cell, and 
when you put two cells side by side, it provides 1/4-inch pathways 
between the cells. So, is there any 1/4-inch OCD plastic tubing that 
would work? I've looked up PEX, but the smallest I've seen so far is 
3/8-inch OCD.

Since my commute is only 60 minutes, I could also put an 25-quart ice 
chest in the trunk, and run the tubing through cold water after the 
radiator. If I run liquid in tubing between the cells, is the any 
chance of condensation? 

Bill



> Mark Grasser wrote:
> > I like the tubing idea, in the summer run it through a radiator, in the
> > winter through the heater. Heater being the factory hot water heater using a
> > heat element in a small tank. Controlled by a temp sensor in the battery
> ...


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## EVDL List (Jul 27, 2007)

Look into PC water-cooling. They have a lot of smaller diameter
plastic tubing as well as heat sinks to hook up and circulate through.



> Bill Dennis <[email protected]> wrote:
> > There are multiple channels that run along the edges of each cell, and
> > when you put two cells side by side, it provides 1/4-inch pathways
> > between the cells. So, is there any 1/4-inch OCD plastic tubing that
> ...


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## EVDL List (Jul 27, 2007)

The plastic tubing used for air lines in fish tanks might work well.



> Bill Dennis <[email protected]> wrote:
> > There are multiple channels that run along the edges of each cell, and
> > when you put two cells side by side, it provides 1/4-inch pathways
> > between the cells. So, is there any 1/4-inch OCD plastic tubing that
> ...


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## EVDL List (Jul 27, 2007)

> There are multiple channels that run along the edges of each cell, and
> when you put two cells side by side, it provides 1/4-inch pathways
> between the cells. So, is there any 1/4-inch OCD plastic tubing that
> would work? I've looked up PEX, but the smallest I've seen so far is
> 3/8-inch OCD. 
Yes. There is polyethylene and nylon tubing that is white and is used
for air. We used it for water all the time and I think people use it for
icemakers. I have seen it at Our Supply House with all the fittings.

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## EVDL List (Jul 27, 2007)

> Bill Dennis <[email protected]> wrote:
> > There are multiple channels that run along the edges of each cell, and
> > when you put two cells side by side, it provides 1/4-inch pathways
> > between the cells. So, is there any 1/4-inch OCD plastic tubing that
> ...


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## EVDL List (Jul 27, 2007)

> Evan wrote: =
> 
> >Frankly I think you're pushing the cells too hard though, and you're =
> 
> ...


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## EVDL List (Jul 27, 2007)

I use jet cooling to cool my NiMH modules, it sounds fancier than it is.
Under neath the floor of my battery box there is a plenum which is
pressurized by a squirrel cage blower. Between the battery modules I drilled
rows of holes in the floor that the air comes shooting out of. This
arrangement ensures fairly even airflow between all the modules.

Here are some pictures of my battery box:
http://www.electric-lemon.com/?q=3Dnode/256

Just blowing the stationary air between the modules out of the box makes a
world of difference in temperature.



On Mon, Aug 25, 2008 at 3:41 PM, [email protected] <[email protected]>wro=
te:

> If you read my post from yesterday, you know that my cells are heating up
> to 55-degrees C in 35-degree C ambient air. Anyone have recommendations =
on
> how to cool a pack of 35 200Ah cells? I'm thinking maybe I need to
> dissipate 1-2Kw of heat on average (pack sags 15 volts at 100 amps).
>
> Bill Dennis
>
> --------------------------------------------------------------------
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>
>
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>


-- =

www.electric-lemon.com
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## EVDL List (Jul 27, 2007)

Perhaps you should contact ThunderSky about these problems.




> [email protected] wrote:
> 
> > Evan wrote:
> >> Frankly I think you're pushing the cells too hard though, and you're
> ...


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## EVDL List (Jul 27, 2007)

> Jeff Shanab wrote:
> 
> > Maybe the Pro-Imp's technique of using the plastic corroplast or spacers
> > bettwen them for airflow?
> ...


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## EVDL List (Jul 27, 2007)

> [email protected] wrote:
> 
> > Hm. Using Uve's, I sized the pack to work at .33C in normal
> > 65 mph freeway driving, and that's about spot on with what
> ...


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## EVDL List (Jul 27, 2007)

> [email protected] <[email protected]> wrote:
> > Evan wrote:
> >>Frankly I think you're pushing the cells too hard though, and you're
> >>not going to have this problem for much longer.
> ...


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## EVDL List (Jul 27, 2007)

Evan, it's a 200Ah string and a 90Ah string in parallel. On a flat 
stretch of road at freeway speeds, it draws about 100A.

Bill Dennis

Evan Tuer wrote:
>


> [email protected] <[email protected]> wrote:
> >
> >> Evan wrote:
> >>
> ...


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## EVDL List (Jul 27, 2007)

This particular one is 118V nominal, 40Ah capacity, 32 cells in series.

Victor



> Mark Eidson wrote:
> > What is the voltage and AH rating of the water cooled pack in the pictures? me
> 
> >> http://www.metricmind.com/images/kokam.jpg
> ...


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## EVDL List (Jul 27, 2007)

Roger,
We had a bit of cooler weather here today, so I took the car out for a 
21-mile round trip spin and measured the temps at various points. 

1) Cells started out at ambient: 25C
2) Temp after first half of drive (mostly downhill): 27C
3) Temp after first 4-mile, 400-foot climb: 32C
4) Temp after final 6-mile, 1700-ft climb: 41C

So maybe air cooling would work. Question: should I pull the air over 
the cells, or push it across them?

Bill



> Roger Stockton wrote:
> > Can you monitor temperature during the drive rather than just at the start and finish? Perhaps even just an indoor/outdoor thermometer with a wireless remote so you can read ambient and the rear pack temp right on the dashboard as you drive?
> >
> >
> ...


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## EVDL List (Jul 27, 2007)

> Bill Dennis wrote:
> 
> > Question: should I pull
> > the air over the cells, or push it across them?
> ...


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## EVDL List (Jul 27, 2007)

> Or chocolate. 

Don't need the aromatic parts, just the cocoa butter...

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## EVDL List (Jul 27, 2007)

I've been half following this thread, and it seams to be getting 
ridiculous.

First, what makes you think 40 - 50 C is such a big problem? Yes, 
that's warm, but is it really worth your time and effort to try to 
keep them cool. ThunderSky lists the operating temperature for their 
LCP cells as -20C to 75 C. 40-50 is well within the range. You may 
actually be getting better performance out of those LCP cells once 
they warm up.

Second, if you feel compelled to do something about it anyway. I 
suggest you K.I.S.S. Just blow some air into the battery compartment 
and be done with it.

What I suggest is to just install a remote thermometer, so you can 
keep an eye on it.





> [email protected] wrote:
> 
> >> Or chocolate.
> >
> ...


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## EVDL List (Jul 27, 2007)

> On 28 Aug 2008 at 17:33, Roger Heuckeroth wrote:
> 
> > First, what makes you think 40 - 50 C is such a big problem? Yes,
> > that's warm, but is it really worth your time and effort to try to
> ...


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## EVDL List (Jul 27, 2007)

Specified peak current for 100216216 power cells is 10C, so
in case of 40Ah cells is 400A.

Victor



> Mark Eidson wrote:
> > What is the max current for a 10 sec acceleration?
> >
> > On 8/27/08, Metric Mind <[email protected]> wrote:
> ...


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## EVDL List (Jul 27, 2007)

Victor,

are you going to use the heat from your battery pack to heat the =

cabin? Do you think the extra energy received is worth a bit more =

complicated setup?

Actually it=B4s not necessarily more complicated, because you can use =

your water heater to warm the battery pack in cold weather. No need =

for heat blankets. Also, the pack is propably heated more evenly this =

way.

I=B4m sure you have considered this. Just curious what was your =

conclusion.

Osmo




Metric Mind kirjoitti 2.9.2008 kello 5.10:

> If (I hope) this product will see mass production, info about it will
> be on the web site. It is OEM oriented product though, and far from
> targeting dumpster divers as potential buyers.
>
> FWIW, less than perhaps 5% of people on EVDL bought anything
> from Metric Mind, so I'm here not to market anything. I just
> offer occasional advice or support the products I have as well as
> check out potentially useful for me links people post.
>
> Victor
>
>


> > Mark Eidson wrote:
> >> Thanks. This would be a perfect pack for my motorcycle.......me
> >>
> >> On 8/29/08, Metric Mind <[email protected]> wrote:
> ...


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