Why the next tablet project should have asymmetrical design

While 99% of the tablets out there are all fully symmetrical devices, I’d like Eve to shake things up a bit.

What is asymmetrical design? On a tablet?

Asymmetrical design means one side of the device is not a mirror of the opposite side. While no tablet is fully symmetric (otherwise you’d have two power and volume buttons), in term of weight distribution and dimensions, they are fully symmetrical.

Note that asymmetrical is not something totally new. Some tablets have existed with this design, namely the Sony Tablet S and Lenovo Yoga Tablet

Xperia Tablet S


Lenovo Yoga Tablet

As you can see on both those devices, if they are laid flat on the table, the screen does not lay flat, instead it forms an angle. That’s a pretty good indication that the design is asymmetric.

Benefit 1: Center of Mass closer to your hand

To fully understand the benefit, we need to talk about the concept of weight distribution and the basics of lever.

As you can see in the GIF above, the closer the center of mass to the lever, the lighter it feels. It translates directly to when you are holding the tablet as well.

The heaviest component of a tablet is the battery (excluding the display, of course, which cannot be moved anywhere), so in this case it makes sense to move it as close as possible to your hand to minimize the distance.

Or to take an extreme example, imagine holding the Lenovo tablet above, but from the thin side, I am sure it would be much harder to hold, due to the lever effect above.

Benefit 2: Less top-heavy in laptop mode

The second benefit is the lower center of mass when you prop up the kickstand. To understand this, we need to go back to high school physics again, mainly the tipping point.

Have you ever wondered why a Jeep has much higher body roll than a Ferrari? This is the reason! Having the center of mass as low as possible is critical in a car, which is why electric cars generally handle better than a gasoline car of the similar class, due to the battery being mounted right on the floor of the car, instead of the engine.

Back to tablets, remember how people are complaining that detachables feel top-heavy when used as a laptop? This is exactly why. Generally laptop’s center of mass is around 0.4 inch / 10 mm above the ground, while a 2-in-1 like the Surface Pro or Eve V in laptop mode can easily reach 2-4 inch / 50-100 mm, depending on the kickstand angle, or up to 10x.


As you can see, the tablet with lower center of gravity will not tip over, even on extreme angle. It will give the user a sense of confidence in handling the product

Here is another magic of low center of mass in roll over test…

Benefit 3: Standardized battery form factor

Enough with the physics, now get to economics.

While most tablet batteries now use non-standard form factors or shapes, some even come in exotic terraced system, standard cylindrical batteries are almost a commodity item. You can find it on (older) laptops, battery banks, all the way to Tesla vehicles.


Inside every Tesla vehicle, there are thousands of laptop battery cells inside. Pictured is the Tesla Model S 70/70D (70 kWh)

And there is a good reason why Tesla chose this battery, it has the cheapest $/kWh rating, which allows Teslas to reach further range than any other electric car. Like seriously cheap, you can get one cell for less than $5. Smart move, Elon!

In addition, it also has the highest density among other form factors, since the form factor is already well-researched.

Let’s get to concepts

The most popular battery cell size is no doubt the 18650 form factor, where the name comes from the 18mm diameter and 65mm height. It also the battery used in the Lenovo and Tesla above.

Alternatively, there is the new type 2170 or 21700 with 21mm diameter and 70mm that’s used in the Tesla Model 3. It has even higher density at the size that virtually feels similar.

image

With that in mind, I designed the concept with 23 mm thickness on the thickest part (21700 battery), to account for worst-case scenario. For the concept, I used 10" form factor, but you can easily scale it down to 8" or up to 12-13"

Oh one more thing, the space next to the battery, which is still around 15mm thick, can be used to store the pen. How about that? Finally a pen can be stored in the tablet!

How much battery life can you get?

The 21700 cell is the most interesting one due to its density of up to 18.5 Wh per cell. On a 10" tablet, you can fit up to three of those cells for a total capacity of 55 Wh, 15% larger than the V, and larger virtually any tablet out there. Remember, this is on a 10" tablet that’s just as big as the non-Pro iPad.

Despite the extra capacity, the weight of 69gr would total to just 207gr, or approximately the same as the battery on the V.

With 18650 cells, you could get up to 3.5 Ah per cell, which means 13 Wh per cell. That still gives you a decent 39 Wh for a 10" tablet (3 cells), still larger than 32 Wh in the iPad and 28 Wh in the Surface Go. On the other hand, we could get 52 Wh on a 12" tablet (4 cells). The weight is around 48 grams per cell, so 144 grams for 3 cells (10") or 192 grams for 4 cells (12")

tldr: By mounting a standardized cylindrical cells on the edge of the tablet, instead of the standard rectangular cell around the center, you could get these benefits

  • Feels lighter to hold with one hand
  • Less top-heavy in laptop mode
  • Higher battery capacity
  • Lower battery cost
  • Pen storage
  • Possibly also easier to design the product with removable battery in mind.

Additional links:

12 Likes

The battery idea is really appealing, are they obligatory linked to an assymetric screen?

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If you want symmetric design with 10mm thickness, for example, then you’d need a battery cell that’s less than 7mm thick, since it has to sit under the LCD panel. As far as I know, those are very few and far between, which is why most tablets use custom cell instead.

Just wondering about thin at the top and battery-enough thick at the bottom: Keeps all your weight distribution explanation intact.

this reminds be of the x1 carbon tablet from a few years ago. i think it was the best of both worlds, it was an ordinary V like tablet with modules the snapped onto the bottom like an extended barrel shaped battery or even a projector.

pretty cool idea

8 Likes

Oh wow this completely went under my radar! Unfortunately it looks so ugly with the massive chin under the display. If they shaved maybe just 1 cm / 0.4 inch off the bottom bezel, I think it would look much better.

2 Likes

I’m fine with this, but am more concerned about ports and the way the controllers would attach to the device.

Ther must be a lot of room in such a thing. See the V :heart_eyes:

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That x1 Carbon concept is cool. I really like the battery life that can be achieved with the cylinder. Projector is rad too!

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In my opinion, from the picture above, do other manufacturer design the kickstands which contain the battery inside?

Small amount of weight can be absorbed by using that as a kickstand battery shell.

Also, it can be easy to replace if damaged or too old, just few screw off and then take it off. This prevent screen damage for this type of machine which use adhesive instead of screw for screen assembly.

Other point is that once you use this “battery kickstand”, battery can be separate from the mainboard which facilitates the cooling.

So, in addition to Patrick’s post, I would like to propose this “Battery kickstand” idea into the design.

Cons for my opinion is that It is relatively easy for pair cable break. (Which the cable must be in the way between hinges.)

:thinking:

3 Likes

This asymmetrical design is an interesting concept however I don’t think you have accounted for the heat dispersion and dissipation with such a design.

A symmetrical design allows for heat to be distributed in an even manner which prevents heat hot spots from forming as a result of undesirable tightly-focused local temperature variations concentrated in one area. The temperature difference can be up to 5-15 degrees cooler with heat dispersing in an even manner in all directions…which is a substantial difference.

Another common problem with asymmetrical design is that most people prefer ‘order’ to ‘chaos’ and have varying levels of OCD from having something that is uneven in shape and asymmetry.

Also, with the heat dispersion concentrated to the ends of cylindrical shape of the asymmetrical laptop where the standardized cylindrical battery cells would sit will cause the battery lifespan to be reduced and there be an increased wear and tear of the battery components as a result of the hot spots condensing in that area.

But an interesting concept all the same.

4 Likes

Another thing to plug into the mini-PC. I still say the more things you can build that snap together or integrate together, it becomes easier to sell, given the product itself is sound and has value.

@Patrick_Hermawan This pic makes it look like the tablet is up vertically. If it is, I really like that because I would use a tablet mostly for reading eBook manga and web fan fiction. Probably not what most people would use one for but they are nice for that if someone loves reading and the tablet is reasonably priced. What if someone wanted to use it for watching movies or youTube? Would they have to hold it or prop it up with something? Or does the hinge turn such that you could sit it on the table tray on the airplane and have it angled back a bit so you could watch the screen without scooting down in your seat?

I guess another thing you could do is use is to take photos and video and then use a USB-C Tbolt to download to mini-PC or media storage device for safe keeping.

1 Like