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Yecup... something seems to be wrong here. (self.shittykickstarters)

skizmo が 投稿

A mug that can cool you drink to 10 degrees celsius or heat it up to 70 degrees celsius. Sounds nice... but when I look at the design picture, it doesn't look like that it is capable of doing that. All I see is a mug with a fan and coolribs in it. They also claim that it has specially designed batteries of 2x 5000 mAh in there and it only weighs 350 gram. I'm not an expert on it, but is sounds a bit too good to be true. They tried it before with another design, but didn't get funded enough. Any thoughts ?

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[–]exclamationmarek 12 ポイント13 ポイント  (1子コメント)

This actually might work.

I'm not saying this specific campaign can end up delivering a product as described, but the product described is completely feasible.

So the device has a 7.4V 5000mAh battery (two cells 3.7V each, that's what they probably mean by 2x5000mAh). That's quite a hunk of battery, but should fit the form factor, and more importantly, should be able to drive a 50W thermoelectric device with ease.

Such a device can be quite efficient when working with small temperature differences. This experiment on youtube measures the efficiency of such a process when heating water from room temp to nearly 50°C, and the result was 260%. I know, an efficiency of over 100% seems weird, but here we are taking about the efficiency of MOVING heat. That is, we use 100J of energy to MOVE 260J of energy from point A to point B, not to PRODUCE 260J of thermal energy. Just like you use less energy walking to McDonald than you get from that bigmac, so the caloric efficiency of such a trip is also >100%.

That being said, to heat up 300ml of water from 20 to 50°C we need:

(50-20) * 300 * 4.2 = 37,800J

(4.2 is the specific heat of water, most drinks are mostly water, right?)

Decided by that efficiency, ~15,000J

15,000J = 15,000 watt-seconds, so that 50W thermoelectric element would have to work for 300 seconds, or 5 minutes to achieve that.

Sounds completely legit. The total battery capacity is 37Wh, so this can be done at least 6 times on a single charge, reasonable.

Cooling follows the same math, the only potential issue being fluid convection working AGAINST us. It's easy to heat up a liquid from the bottom, since as soon as a portion is hotter it expands and floats UP, pushing the cold portion DOWN towards the heating element. This way it self-mixes itself and the heat is distributed equally. If we cool something from the bottom, we will end up having the bottom frozen and the top warm, but if the entire container is made out of thick and conductive metal, I guess this could work, possibly requiring a slight shake or two.

The 350g does sound a bit optimistic though. And controlling this from an app is just plain stupid, but other than that, this concept is legit by my standards.

[–]splenetic 2 ポイント3 ポイント  (0子コメント)

Cooling doesn't follow the same maths.

Let's take your example of moving 260J of heat energy, and in the process, consuming 100J of electrical energy to do it. That 100J doesn't vanish. It appears as heat generated in the peltier elements themselves. If you're using Peltier elements to heat something then that's fine - that extra 100J isn't going to be wasted, it'll be dumped into the liquid as well as the 260J you're moving from cold side to hot side. Your drink just gets that bit hotter.

But when you're cooling, that 100J is working against you. That 100J is trying to heat up your Peltier element which is exactly what you don't want to be happening. This means that a Peltier element's overall efficiency while working as a cooler is significantly less than its ability to work as a heater.

There are other issues. Let's say you're out on the ski slopes and you want to use your Yecup to heat up your coffee. The hot side of the Peltier element starts getting hot and the cold side cold. If the ambient temperature is very low then you've got a problem - effectively you want the cold side of the Peltier element to be pulling heat energy from the environment to then be able to pump into the coffee. But if the environment's cold then it won't work well as there isn't enough environmental heat to keep the Peltier's cold side at a workable temperature.

The reverse is true as well - if you're out on the beach, the sun's shining down and you want your Yecup to make a nice chilled drink for you, it's going to be pumping heat energy out of the drink and trying to dump it into the environment. But if the environment itself is hot then it's not going to be able to work very well as it won't be able to shed heat.

Essentially, then, the Yecup will be most efficient if you want it you produce you nicely chilled drinks on a cold day or lovely warming coffee when it's sunny.

[–]Dylan16807 5 ポイント6 ポイント  (24子コメント)

Their diagram is nonsense but the basic concept is okay. Just assume that a thermoelectric cooler slots in between heatsink and cup, and that they actually remember to put the battery in there somewhere.

It would struggle to change the drink temperature very much off of battery, but it should more or less work as described.

[–]gurenkagurenda 1 ポイント2 ポイント  (10子コメント)

It looks like they're relying on passive airflow, and I'm seriously doubtful that a unified design can do that for both heating and cooling. Doing it for even one would require some extremely careful engineering.

Now they do have several engineers involved who, without digging, appear to be pretty smart people. But none of them look like they have experience in this particular kind of engineering.

So I'd feel way more confident that they'd really pulled this off if it contained a fan, because that would just make the problem way, way easier.

[–]Dylan16807 1 ポイント2 ポイント  (5子コメント)

Doing it for even one would require some extremely careful engineering.

For heating with a TEC you can just dump voltage into it and pretend it's a resistor. Airflow doesn't matter. Cooling is the part where you need to be careful.

[–]gurenkagurenda 0 ポイント1 ポイント  (4子コメント)

You can do that, but you're not going to get the majority of the benefit of using a TEC if you don't warm up the cold side.

Keep in mind, heat pumps used for warming homes get something like 4 times the thermal efficiency of electroresistive heaters. You get both the heat generated by the component, and the heat you extract from the environment.

And that's going to matter if you want to heat beverages to 70℃, because the specific heat of water is ridiculous.

[–]Dylan16807 0 ポイント1 ポイント  (3子コメント)

While it is wasteful, if you have the power budget to cool a beverage with a TEC, you should have the power budget to heat a beverage despite being inefficient. Your ideal efficiency isn't 4x once the drink starts to heat up. Probably closer to 1.5x.

[–]gurenkagurenda 1 ポイント2 ポイント  (2子コメント)

Heat pumps can get 4x efficiency in the winter. I don't know what the efficiency is like for TECs (it's worse), but it's amazing how much heat you can squeeze out of an environment.

[–]Dylan16807 0 ポイント1 ポイント  (1子コメント)

https://www.ferrotec.com/images/technology/thermal/sec11-f4.gif

https://www.ferrotec.com/technology/thermoelectric/thermalRef11/

This is the chart I found. For that 'standard' module, when fighting a 25 degree gradient at about room temperature there's a peak of 2x efficiency. To get a drink up to a toasty 70, your efficiency is not good at all.

[–]gurenkagurenda 1 ポイント2 ポイント  (0子コメント)

Makes sense. It's probably not negligible though, and given that a passive airflow system is likely going to be totally insufficient for cooling a drink to 10℃, it really seems like they should just put a fan on it.

[–]exclamationmarek 1 ポイント2 ポイント  (3子コメント)

Doesn't that 3d model have a fan drawn between the circuit board and the heatsink? You can kind of see the blades.

[–]gurenkagurenda 0 ポイント1 ポイント  (2子コメント)

Oh huh, you might be right. Not sure where the TEC is in that image, but yeah that might be a fan. In that case this might work.

[–]splenetic 0 ポイント1 ポイント  (0子コメント)

The TEC would have to be between the bottom of the cup and the top of the heatsink. But it, like the large battery, aren't shown because reasons.

[–]exclamationmarek 0 ポイント1 ポイント  (0子コメント)

glued to the top of the cooler, you can see the characteristic "notch", shown as a sandwich of one smaller plates between two wider ones. They used a single shade of metallic grey for the whole thing so it's not too prominent but it seems like a TEC to me.

[–]skizmo[S] 0 ポイント1 ポイント  (12子コメント)

Hmmm... I think that batteries itself weight more than 350 gram. Also, cooler and heater elements ? Have to see it before I believe it.

[–]splenetic 5 ポイント6 ポイント  (4子コメント)

A Peltier effect device can be used to heat or cool - or, rather, it can move heat from one side of it to the other and the direction can be changed by reversing the current.

They're very inefficient though; the hot side gets a lot hotter than the cold side gets cold if you see what I mean, so the hot side needs the heat sink plus fan to stop it getting so hot the device fails. Plus Peltier effect devices need a lot of electricity to make them work so all in there's a lot of load on the battery. 10,000mAh isn't to be sniffed at though.

The downside is that for 10,000mAh you'll need three or four 18650-sized Li-Ion cells, each of which is a bit bigger than a standard AA-size cell. That's a lot of room taken up in a travel mug, plus the heatsink and fan, PCB for charging, bluetooth (wtf?) and "selfie" capability (double wtf?).

I don't think they'll have a hope of it fitting in to the size and shape they're aiming at and I can't imagine it will work brilliantly well even if they do.

[–]Dylan16807 4 ポイント5 ポイント  (1子コメント)

The room for heatsink and batteries is the important part, but the bottom of that thing is pretty big.

I don't know specifically about bluetooth, but you can get a tiny wifi-capable microcontroller for $4. Using a chip with wireless so the phone can handle the controls makes enough sense, and making a button trigger selfies is silly but essentially free.

[–]splenetic 0 ポイント1 ポイント  (0子コメント)

Fair point about the space needed for the microcontroller etc is so small as to be irrelevant. But the batteries will take up at least half of the available room.

[–]Paremo 0 ポイント1 ポイント  (0子コメント)

Also the batteries are right next to the drink in their diagram so a) The battery is going to get heated if you put something hot in there and b) the battery will re-heat the drink you are attempting to cool down.

[–]mbirth 0 ポイント1 ポイント  (0子コメント)

The good thing about Peltiers is, you could fill in superhot coffee and use the heat vs. room temperature to recharge the battery a bit - like recuperation on an electric car.

[–]Dylan16807 1 ポイント2 ポイント  (6子コメント)

I can't comment on whether the total weight is realistic, but the two batteries would not have to be much over 100 grams each.

Here's a ten pack of suitable cooling/heating elements for $26: http://www.amazon.com/Vktech-TEC1-12706-Thermoelectric-Cooling-Peltier/dp/B00IKDL22O/

[–]skizmo[S] 1 ポイント2 ポイント  (5子コメント)

Thanx... I thought they would be heavier. According to the design picture they would be stuck to the sides. Don't think that batteries like the continuous changing of the temperature.

[–]Dylan16807 1 ポイント2 ポイント  (4子コメント)

I would just ignore the picture entirely.

[–]skizmo[S] 1 ポイント2 ポイント  (3子コメント)

You're probably right... but that makes me a bit suspicious... why put bullshit on there if your product is real ?

[–]mrv3 2 ポイント3 ポイント  (1子コメント)

Also, to heat water from room temp to 70 degrees takes 52,000 joules ATLEAST for the 314ml model.

An iPhone battery which are often some of the most energy dense and contain roughly 25,000 joules. You'd need at least 2 batteries to do one cycle at perfect efficiency which you do not have.

You can do pretty much the exact same job with 1 $20 thermos except it'll last longer, no need recharging, doesn't degrade and bigger sizes.

This is useful if...

There isn't a use. If you want something hot you make hot initially, if you want it cold you make it cold a thermos keeps it cold.

[–]Paremo 0 ポイント1 ポイント  (0子コメント)

They claim 10000 mAh, that's 6 times as much as the iPhone (5) has, according to google, and a little more than 3 times as much as a 6 plus.

Also, heating a drink up from room temperature would most likely not be the preferred method of operation.

[–]Dylan16807 0 ポイント1 ポイント  (0子コメント)

It's more "intern-quality" than "bullshit" but you're right that it's not a good sign.

[–]Vigen92 0 ポイント1 ポイント  (0子コメント)

Hi there , My name is Vigen and I'm the CEO of Yecup. I'm very disappointed that our campaign appeared next to Fontus bottle or Triton scams. I have came here to explain everything :) First of all I want to say thank you for your time while reading this, I've read everything here and people are right, because our 3D model and tech specs are not 100% correct so let's ignore them. Currently we have working prototype and team is working on DFM, we changed the battery it's nominal voltage will be 11,1V and capacity about 4-5Ah .We've ordered samples of curved batteries to test them, with that capacity it's totally possible to heat up drink from 10-70C easily, while it's not so easy with cooling. Yes u're right we're using TEC module but we've found very good one which costs about 15$ it works not as the 1-2$ Peltiers ordered from China, the maximum temperature difference between layers is 74C it's enough to cool down for example from 40C to 10C , the only thing is to keep cool the hot side , for that we're using Sunon fan 7500 RPM which costs about 10-6$ per unit (depends on quantity) and heat sink which is connected with mug's outer layer(and the outer layer serves as a heat sink as well ) . Hope now it's more clear :)

P.S I've personally contacted with Indiegogo Marketing/Trust and safety teams as it's very very unfair to promote campaigns like Fontus which is scientifically impossible , but as far as I understood indiegogo don't care , they support obvious scammers . If I know that before I'd not post our product on IGG , they've very bad reputation and people lost confidence in every single product even if it's real and working like ours.

P.P.S sorry for my english, you can chat with me directly via my email (vigensanahyan@gmail.com) of course if you want to :D Take care, Yecup CEO Vigen

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