After 2 years : swollen batteries

[ericzered]

Hello,
2 years ago, I've create an android device lab like the one in this project. I've plugged 18 android on 2 Anker USB 3.0 9-Port Hub + 5V 2.1A Charging Port, 1 hub plugged to 1 Mac Mini.
Everything was ok, I was able to make Appium auto tests, etc...
But after 2 years, I have a lot of swollen batteries. One year ago, I've scheduled a "power OFF" for the hubs during night to limit this swollen batteries phenomena, but it was not enough.
So I have one question : how do you manage this ? My purpose first was to send a lot of power to the devices so they don't die, but even with this Anker (that you rate 2/10 because of "insufficient power"), it was too much. Now I'm thinking about regular hubs without power supply to see...
Thanks

[gunta]

USB hubs without power are useless since the devices will get discharged fast. You'll not be able to use the devices more than what the charge lasts, which is usually less than 1 day.

If you care about batteries dying after 2 years, the only real solution is to not use batteries at all.

Instead you can use electrical power from an external source to the internal battery connection pads with wires. That's going to be a DIY job and you need care to ensure correct voltages and polarity.

Also, some devices work without having a removable battery connected, just the USB power, so you might try this first.

[ericzered]

Thanks for the fast answer,
I've tried to plug my android without battery and they didn't want to start...
Last year I've plugged a Nexus 6 on my hub and 10 month after the battery looks like it will explose.. Same for my Galaxy Note 3, a Huawei, a Galaxy Tab 4, ect...
So it's more about security (I'm afraid that a phone will start a fire) that care about batteries.
I will try fex days with 4 x 4 ports hub to see if it can deal with charge...

[sorccu]

I think that's the downside of device labs and you can't really do much
about it, short of bypassing the battery at least. I'd say 2 years is a
fairly good run, though. I've heard of cases where they have to change
batteries every few months, but that wasn't with STF - they were using
something else. Our devices lasted for about two years too, now after 2.5-3
years I hear that about half are experiencing similar issues (haven't seen
the situation by myself, though).

If you go with regular hubs you're going to have huge stability issues.
That's the tradeoff. Some devices may be so unstable that you wouldn't even
be able to use them for a few minutes, let alone two years.

On Thursday, 15 September 2016, ericzered notifications@github.com wrote:

Thanks for the fast answer,
I've tried to plug my android without battery and they didn't want to
start...
Last year I've plugged a Nexus 6 on my hub and 10 month after the battery
looks like it will explose.. Same for my Galaxy Note 3, a Huawei, a Galaxy
Tab 4, ect...
So it's more about security (I'm afraid that a phone will start a fire)
that care about batteries.
I will try fex days with 4 x 4 ports hub to see if it can deal with
charge...

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[codeskyblue]

I have an idea but never tried before. Because some device have to got a battery so the device can be started. What about change the battery into a large volume capacitor. So there is no worry about the swollen batteries problem. ^_^

[sorccu]

Yes, removing the battery and replacing it with a static power supply is a good method, but labor intensive and quite a bit of knowledge is required to make sure you don't fry your device. Plus some devices are difficult to open, as they don't have replaceable batteries. In any case I've seen a working example of that.

[sorccu]

Personally I'm thinking an occasional "battery conditioning" might help. For example, you could cut off the device for a day or two once a month or so, until it has <20% or <10% battery left, and then reconnect. It may prevent the issue from happening, but obviously testing would be required.

[codeskyblue]

Device complains about that I need to rest every month. :)

[LeoVie]

Did you find any solution for this?

[sorccu]

There is no solution, however you can significantly reduce future issues by introducing airflow. Buy a few fans (USB powered are fine) and make sure they're blasting directly at the back side of the devices.

[LeoVie]

Do you have experience in the airflow stuff? How should this stop the batteries from gasing?

[sorccu]

It’s a small investment. Why not try it out?

[LeoVie]

That's right. Did you try it and do you have some statistics over the effect of the fans?

[sorccu]

I don’t have any “proof,” however I can say from personal experience that after applying constant airflow to a set of devices (a few of which had already started to expand), not a single new device went bad and the ones that had swollen already did not get any worse. It’s been running pretty much unchanged for over a year since airflow was added.

[C14427818]

Hi all, I have been running constant tests on 2 phones using Appium and OpenSTF. Unfortunately both phones batteries have swollen after 3/4 months. Are there certain phones that you are using so that the battery life is prolonged?? Any feedback is greatly appreciated.

[nikosChalk]

Hi, sorry for resurrecting this thread but I couldn't find any solution online. We have a small STF lab, running on a raspberry pi, with only a handful of phones that we want to occasionally use remotely.

We wanted a low-cost, small-scale, and remote solution. So, we ended up using a smart plug to cut off the power to the USB hub, adb to issue a delayed shutdown to the phones, and the "boot when power is detected" feature of the android phones.
A detailed README and limitations of our setup can be found in our repo (Devices on demand guide).