Ego Keep Cool Technology Exposed!

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  • Updated 3 years ago
OK people here it is, a look deep behind the curtain... There's no wizard, but something else equally impressive.

Workshop Addict has just cut into a keep cool cell in an Ego pack to show us all a little bit of the magic that makes this platform so special:

https://youtu.be/dnFWbuVxbZM

Ok, so it's not all that exciting, but if you understand the physics behind what's going on it's some pretty cool stuff! (See what I did there?)

Combine that with a wicked intelligent, forced-air cooled, high current battery charging system and you've got what we have come to know as the most advanced battery and charger platform on the market!

Toss in some top-shelf tools and presto - instant market leading performance! :-)
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Blue Angel, Champion

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Posted 3 years ago

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Jacob

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Here is how it actually works. The gel material is know ans PCM (phase change material) phase change is basically solid to liquid, liquid to gas. PCMs use solid to liquid and vice versa. To better understand PCMs, imagine water freezing. For water to get from 34 degrees to 33 degrees it takes 1 btu of energy per pound of water. To go from 32 to 32 frozen it takes 144 BTUs per pound to be removed. 144x the energy than to just change phase vs 1 degree F. So basically it can be used as a "thermal storage device" like EGO is using it for.
Nothing else has nearly as high of a"latent heat of fusion" than water. The desired phase change point is what the specific material is designed around. Mostly above freezing is wax based, and some salt water soutions. Below freezing is generally salt water blends.
(Edited)
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TheAtomTwister

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Why don't you give that in Joules? For those interested, a BTU is about 1055 joules, and to heat up water 1 degree celsius, you need 4.184 joules per gram, 4184 joules per kilogram, and considering that a BTU is about 1055 joules and there are 2.2 pounds in a kilogram, which equates to 2321 joules to heat up 1 kilo of water 1 degree celsius... that does not match the specific heat of water. The point is that it looks like Jacobs figures are off by about 40%, and actually the energy needed is almost double what he says.  

My point is that somebody somewhere got it wrong. Maybe the guys that said that the BTU is 1055 joules, the guys that say that the BTU heats 1 pound of water up 1 degree celsius... wait, you're talking degrees fahrenheit... 

ooooops. never mind, Jacob's right.
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Jacob

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So there. ;)
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Blue Angel, Champion

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OK, so I'm officially incapable of explaining Phase Change and Latent Heat by memory with anything resembling accurate information (college was a LONG time ago), so I found a YouTube video that explains it.

This guy is a bit annoying, but it's all I could come up with quickly that didn't sound like a boring physics lesson:

https://www.youtube.com/watch?v=6lAxBTLgYfU

So taking Jacob's example above regarding using a wax type Phase Change Material, imagine that the wax PCM melts at about 30C (just an example, I don't know the melting temperature).  The video uses water as an example, which changes phase from solid to liquid at 0C, so just imagine the exact same thing happening at 30C.

The cells in an Ego pack are free to increase temperature under heavy load until they hit 30C, at which point the PCM starts absorbing heat and maintaining the temperature of the cell.

A competitor's product (any competitor, really) without PCM wrapped cells will see the cell temperature continue to increase under load.  If the temperature gets high enough the battery's thermal protection will kick in, limiting power to the tool.  Also, running at elevated temperatures reduces the life of the cells, which is very bad.

The fan cooled Ego charger then freezes the liquefied PCM while charging and then cools both the PCM and the cells to below the PCM melting point and the cycle can repeat itself.

I just can't stop linking to this video... it clearly demonstrates how good the EGO design really is.  The 2Ah Ego pack in the 480cfm blower on turbo vs. the Echo 2Ah battery and their blower on high, in repeated use:

https://www.youtube.com/watch?v=8jPgrPtGH7o

In a nutshell (it's a long video), the Ego spends twice as much time blowing per minute of charge time... the Echo battery sits on the charger FOREVER waiting to cool down enough to accept a charge, while the Ego is cycling continuously through its battery over and over with very consistent performance.

Way to go Ego!  No wonder it took such a long time to develop and launch this line of batteries!  :-)
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TheAtomTwister

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You can buy nonfunctional EGO batteries off of eBay and gut them for good cells and then integrate those cells in place of the cells in a battery that lacks cells with phase changing bands on them theoretically. It'd be some work and you'd void the warranty of the battery you're working on, but that would be something I might not mind doing if it acts as an upgrade.

For fans of Barnaby, here's this: https://www.youtube.com/watch?v=2LP0gzGtsic
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Jennifer VandeWater, Community Manager

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Official Response
Blue, thanks for sharing this.  We also love this video and are featuring it on our social media next week!