The X900: A Teardown

Nate returned from his China trip with a treasure, so we tore it apart.

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At some point soon after returning from China (where he also got the inside scoop on several suppliers' factories), Nate wandered into the office with an unmistakable look of glee on his face and a mysterious object in his hand, which usually means one thing: Teardown time.

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This time around, what Nate found in China was the DDC Mobile X900 - a mobile device of incredible weight and bewildering faculty. Naturally, his next step was to have Creative Technologist Nick Poole see what’s doing in there. And boy did he.

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If you’re wondering what Nick found in there - including an insect-averse panda game, an enigmatic offering of “sbook,” and several features worthy of 007 - you can see his full, entertaining teardown here.

Enjoy!


Comments 25 comments

  • C ratings are usually optimistic and are often rated at 1C rates or less, manufacturers don’t usually have good information on what happens to the C rating as you discharge at higher C rates. I’ve even seen one battery listed that the C rating holds true for .1C, which was on a 90mAH battery, I’m like, who the heck buys a high discharge battery to use it at 9mA?

  • I wonder about the legality of operating this device in the US? Good thing it got torn down before the FCC came looking for you.

  • Dude, that solder work on the V100_PCB_V2.0 is a thing of beauty, LOL!

  • I probably shouldn’t have to point this out, however there are some 18650 power cells that are made to discharge at a much higher current than what’s printed on the wrap. But, they are also properly labeled Li-Ion Power Cell, not a regular Li-Ion cell. Case in point, Tenergy makes an 18650 rated at 1500mAh, however you can discharge the thing at 10C, or 15A (max burst is 20A) - I use them in LED designs all the time. So, while that battery says 2000mAh on it, it’s still possible that it’s capable of the full 8A listed on it. On the other hand, the Chinese are known to make cheap knock-offs so testing the battery is really the only way to find out what its capabilities are.

    • 2000mAh should note the capacity. You could draw that out at any current rate you want (so long as the battery can handle it), but total charge is 2000mAh. if you draw 4000mA it will last 30 minutes. 8000mA, 15 minutes, etc.

    • LightManCA has you on this one, man. 2000mAh is the rated capacity. Whether you draw it at 1C or 10C, there’s no getting around it.

      • The 18650s I’m using are 1500mAh power cells that I’m pulling 4-5A out of them consistently and they’re lasting 6-8 hours. So what’s the magic there?

        • No idea, but if those figures are right then this is indeed magic. Two things come to mind: 1) Is your load actually running at 100% duty cycle or does it just seem like it’s running continuous because your eyes/meter are too slow? 2) Is your load running at battery voltage?

  • Yikes, that antenna!! There is no ground on it and it’s just a piece of wire to connect it- not a coax. The performance must be horrible. Compare with the shielding on a real brick phone.

    • I have my suspicions that the fancy looking antenna on top of the phone is actually the FM radio antenna (I know, don’t get me started) and that the quad-band antenna is wrapped around the speaker enclosure. I can’t imagine that the one wire duck on top of that phone would pick up anything at 850MHz

  • 1992 called. They want their phone back.

  • Nick I wonder if you are being over optimistic on that one battery actually being 2000 mAh. See a lot of “2,200 mAh” 18650 batteries where “2,200 mAh” is part of the name not a spec and they are maybe 1,500 if that.

    • At this point, I’d be pleasantly surprised if I unwrapped it and didn’t find a crude electrolytic cell made of 1 jiao coins and lemonade.

  • I just want to know how it would use two sim cards…

    • Dual SIM phones are actually amazingly popular in many countries. It allows for people to have a single phone for work/business and personal use, or to have separate plans from different carriers for data/texting/voice/etc.

      As far as the function, it should just be controlled through the software side of things, which SIM module connections go though. Pretty cool stuff, and it’s starting to gain a little traction in the US now too.

  • While I’m not terribly interested in getting one of these phones, I am interested to know the cost. I want to see how close Nick can come to being cost competitive. As a side note, did Nate feel vulnerable to hackers/what precautions did he take while on this field trip?

    • I receipt was in the bag (that I recently lost track of) but I think it was 175RMB or $28.

      We used a VPN most of the time out of necessity. It’s interesting to watch how the Chinese internet looks like it will, but never quite loads the Tiananmen Square wikipedia page. Lack of net neutrality is a scary, scary thing.

      • Interesting that it even looks like it tries. Not sure what this has to do with net neutrality, sounds more like a government censorship thing to me.

        • I worry that the lack of net neutrality in the US will open the doors to companies that slow down certain sites (like bitorrent) to the point they are effectively unreachable.

          What we experienced in China was pretty creative actually : it wasn’t censorship per se because some pages would sometimes load at some point. The throttling was then varied to make it super annoying.