[ONE General] vantt1:
Meh, might as well. Repost from OnePlus Forums.

Update: finally added the Note 2 battery's weight :p

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I should add that I facilitate no allegiance to any particular phone brand, nor am I sponsored by any phone brand. I work for myself, and make my own decisions based on fact, not personal biases. I love the OnePlus One as a phone, I just don't like what the company is doing to their customers.

It all started when I created a thread about the iPhone 5C's battery being able to be upgraded. I was then met with the question: "Why didn't OnePlus make the battery on its One removable? Another manufacturer, Samsung, could make a phone that had a larger removable battery in a form factor that was thinner and shorter than the OPO, even with the addition of a MicroSD slot and a USB 3.0 port." I was informed that OnePlus chose to make their battery non-removable, because if they did, it would end up being a 2500 mAh cell, 80% that of the current 3100 mAh, due to the inclusion of a protective shell, regulatory circuitry, spring contacts etc.

Then I thought, "Weird; the 5" Samsung Galaxy S4 has a removable battery, but it has a 2600 mAh battery!" So to settle things once and for all (for now), I went ahead and disassembled my OnePlus One, to compare its internal battery's volume with a removable equivalent, the Samsung Galaxy Note 2's (also 3100 mAh). Seeing that OnePlus warranty is near non-existent anyway, even if the phone did fail or malfunction due to manufacturer fault, I'd just get another phone to save the trouble of going through RMA hell.

Centimeter grid, for your convenience

Now, I'm not going to dissect the batteries; rechargeable cells are very dangerous, and can explode if punctured. So, I measured the dimensions of both batteries to calculate their respective volumes. I didn't have a digital scale on me, so I couldn't calculate the energy density of Li-ion (Note 2) vs. LiPo (OPO).

The dimensions (in milimeters) of the batteries are as follows:

OnePlus One

Length: 83.39 mm

Width: 57.84 mm

Thickness: 4.38 mm

Volume: 21125.96 cubic mm

Energy Density (power/weight): 230.98 Wh/kg

Volumetric Mass Density (weight/volume): 0.0024 g/cubic mm

Note 2

Length: 75.00 mm

Width: 55.44 mm

Thickness: 5.65 mm

Volume: 23492.7 cubic mm

Energy Density (power/weight): 226.54 Wh/kg

Volumetric Mass Density (weight/volume): 0.0022 g/cubic mm

This makes the volume of the OnePlus One's battery 89.9% that of the Note 2's, so the percentage difference is only 10.1%. Keep in mind that this is lithium ion vs. lithium polymer. Li-ions need more protective circuitry to prevent overcharging and exploding and whatnot, compared to their LiPo counterparts. And from what I heard,

LiPos have a higher energy density than Li-ions

, which is why I wanted to calculate how much the batteries weighed as well.

Edit: The OnePlus One's battery has a comparatively higher energy density (1.8% higher), a smaller volume, and a higher mass density (8.3%!!!!) than the Note 2's, meaning a LiPo battery should provide more power than a Li-ion of the same weight and volume. But, since the difference is so small, it's probably going to cancel out once we take into account the protective shell and protection circuits and whatnot. In conclusion, the point below still stands due to the negligible difference because it is calculated based on the removable equivalent having around the same specifications.

Just going by these numbers, a removable equivalent for the OnePlus should be roughly

2780 mAh

(10.4% decrease), not 2500 as OnePlus has claimed (a ~20% decrease). Of course, this is inconclusive, but this should give you a better idea of what's actually happening here.

The Galaxy S4 featured here is the LTE-A version, sporting a Snapdragon 800 chipset, more closely related to the OPO's Snapdragon 801 compared to the Snapdragon 600 S4.

I have discovered that the OnePlus's processor may not be adequately cooled. Since smartphones are passive devices, they aren't actively cooled by fans like computers are, so they rely on heat dissipation through the use of a heatsink of some sort.

The Samsung Galaxy S4's chassis is made of magnesium alloy, just not as abundantly so as the OPO. The logic board well is form-fitting, and there are thermal pads that contact the underside of the logic board to the chassis in order to dissipate heat. Since the chassis is so big, heat is easily dissipated.

The OPO, however, looks like it's insulated at the area where the chipset is closest to the chassis with what seems to be carbon paper/film. Now, I'm no materials expert (and correct me if I'm wrong), but I'm pretty sure carbon in this state should act as an insulator. I say this because iPhones use the same stuff on the chassis to protect the LCD from heat damage (on the iPhone, the film is on the LCD side and not the logic board side).

On the underside of the logic board, we see that there's a steel cage covering the on-board components, covered by a thermal pad.

What does this mean? It means that under load, a Samsung phone will feel hotter to the touch, because that's the passive cooling system in action. In the case of the OnePlus one, it might not feel as hot as a Samsung under similar loads, but when it does get hot, it's really, really hot. So hot that the small heatsink and carbon film can't contain or dissipate it.

For size comparison purposes, here's the Galaxy S4's logic board next to the OPO's. Remember that the S4 is a 5 inch phone.

Assembly was probably quite sloppy; the tape used to insulate the speaker contacts is off-center on the left speaker.

The weak vibrate motor cannot be upgraded, as it is soldered to the flex.

The earpiece grille is centered on the front of the phone, but it is offset to the left internally because the camera module takes up the space in the center, as can be seen below. This may or may not contribute to the low earpiece volume, since it is channeled.

The rear microphone (pictured below) is also offset slightly lower than the hole next to the rear camera. Outside, the hole is parallel to the center-point of the camera lens, but internally, it is parallel to the top of the flash LED closest to the camera. I'm not sure how effective this placement is. The top microphone (refer to picture above, left of front camera hole) is channeled.

I should update my signature.