Previous posts where guys have listed their computers, show some using up to three androids to crunch WUs in addition to the usual laptops, desktops etc. My current mobile (cell phone) HTC One took 36 hours computing time to crunch the last WU with a GFLOPS rate of 1.20.
My question is how do you set this up as I have some old mobiles I might want to use? Do you have to have a SIM card and therefore pay for having each one on all the time?
The other point I might mention is that keeping the phone connected to the charger all the time (otherwise it won't crunch) gives me concerns about cooking the battery.
TIA
George

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ARM processors are inherently inefficient at compute tasks like SETI@home since they're designed for low power consumption, not number crunching. At only 1.20 GFLOPS I don't really see you gaining much by using even multiple old phones. Then again I run BOINC on an old Athlon 64, and the phones only use a couple watts each, so each to his own :-P

You don't have to have a SIM card or anything, the phones just need a WiFi connection to the internet. As for the battery, you can remove it and run it strictly on the charger without much issue assuming your charger has a high enough amperage rating. Of course assuming your phones have removable batteries.

A good rule of thumb for chargers is that it needs to put out at least 1 amp (5 watts), but more is better.

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one thing to remember is that most phones are not designed to run at full power 24/7,having inadequate in adequate cooling.

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

As it has been said. Without a SIM card an Android phone will function basically like a tablet. The mobile device only needs an internet connection so that BOINC can download/upload work. Wifi is normally the easiest option, but sometimes, depending on the device, it can be configured to access the internet via an USB connection from a PC.

You can run your mobile device several different ways.
-If you set BOINC to only run 1 task at a time it will run the coolest, use the least amount of power, & likely complete work the fastest. Then you might be able to go a normal day letting BOINC run while on the battery & only charging it overnight. On my Galaxy S4 went for this configuration & set BOINC to stop when the battery got to 20-30%.
-You could use your device normally and let BOINC only run when plugged in to charge. If you had it plugged in overnight 7-8 hours it would take a few days for work to complete, but that isn't a problem.
-You could leave the device plugged to a power source with the battery removed to run 24/7.

If you have an interest in running several mobile devices without batteries this article might be of interest to you.
http://www.instructables.com/id/How-to-use-phone-without-battery/

Leaving a lithium battery connected to a charger 24/7 will cause it to wear faster then with normal use. Some have sound that doing so caused the batter to swell and damage the device. If a swelling battery isn't detected soon enough it could be a fire hazard.

My observations have been that most of the heat seems to come from the battery charging/discharging rather than the device processor. Even while setting in direct sunlight charging the CPU temp, while running a single task, didn't reach the point where the clock was throttled.

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SETI@home classic workunits: 93,865 CPU time: 863,447 hours
Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[

HAL, Bob & Empire Builder
Thanks for the prompt ideas - great stuff
George

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Leaving a lithium battery connected to a charger 24/7 will cause it to wear faster then with normal use.

Which for laptops & the like isn't a significant factor in their life expectancy.

Li-ion batteries have a calendar life- from their date of manufacture they have a limited life span, and that is determined by their state of charge & temperature. Batteries with a lower state of charge (% of their maximum possible charge) will last longer than those with a higher state of charge. However the biggest limiter on battery life is temperature. The hotter it is, the sooner they die.
The other limit on battery life is the number of charge-discharge cycles. In the case of laptops this can be as low as 300-500 cycles due to laptop batteries being charged to their maximum possible capacity (for longer times between charges), them being charged as fast as possible (resulting in lots of heat) because people don't like to wait for them to charge, and them often being fully discharged before being recharged.
Batteries that are never fully discharged, only charged to a small percentage of their total capacity & charged at a slow rate (to keep temperatures down) can be good for upwards of 10,000 charge/discharge cycles (apparently Li-ion batteries used in Photo-Voltaic systems if only charged to less than 20% of their capacity can be good for 100,000+ cycles).

Some have sound that doing so caused the batter to swell and damage the device. If a swelling battery isn't detected soon enough it could be a fire hazard.

That is the result of a faulty charger and/or battery.

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Grant
Darwin NT

Grant, that is very good info to know. I go thru laptop batteries much too quickly, due to the fact that they are plugged in 90%+ of the time, used as a desktop replacement. The mfg's must know this, they should have much smarter chargers, and not allow _any_ charging after 100% (and allow the option of slow charging) when the battery is in a docked situation, but they know this, and make a very good profit off of selling replacements. As well as the aftermarket, but those can _definately_ be hit or miss... And I've found that if my laptop has no battery, it won't boot. Such a deal, eh? That one has bugged me for Years.

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Grant, that is very good info to know. I go thru laptop batteries much too quickly, due to the fact that they are plugged in 90%+ of the time, used as a desktop replacement. The mfg's must know this, they should have much smarter chargers, and not allow _any_ charging after 100% (and allow the option of slow charging) when the battery is in a docked situation, but they know this, and make a very good profit off of selling replacements. As well as the aftermarket, but those can _definately_ be hit or miss... And I've found that if my laptop has no battery, it won't boot. Such a deal, eh? That one has bugged me for Years.

Most computer manufactures put somewhere in the documentation that is the notebook will be plugged in for extended periods to remove the battery. I know for some devices, Apple notebooks & many mobile devices, battery removal isn't an option. So the user has to be knowledgeable if they want to have the greatest battery life expectancy & avoid micro charge cycles killing a battery.

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SETI@home classic workunits: 93,865 CPU time: 863,447 hours
Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[

I have 2 ZTE Zinger phones running KitKat 4.4.2; one has no SIM and cracked screen, and the other is the replacement phone... they tend to 25-42 hours per WU, and with 2 cores this implies 7-14 WU per week per handset if run 24/7.

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I'm pretty sure my Dell won't boot up without the battery in it, but I guess I haven't tried it in a year or 2, though I still have the same laptop, so next time I pull it out and use it, I'll give it a shot. Been working mostly desktop recently.

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My ZTE's will start up w/o a battery, but then becomes a game of trusting the power coming through the wall sockets... and no glitches that would cause it to reboot back into the lock/login screen...

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