Page 2 of 2

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Thu Sep 22, 2016 1:08 pm
by mattmiller
All fine after 5.5 hours

Volts is down to 4.6

I think I'll have to rig up another Pi with an ADC on it to monitor the volts next time and see how long it actually stays about 5.25V - I suspect not much more than 1 hour

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Thu Sep 22, 2016 2:36 pm
by mikerr
mattmiller wrote: (I know its not legit but I have a need to use 4xAA batteries in a project - I will specify that they should be NiMH recharables but I needed to know what would happen if a user didn't follow the plan)
You have only proved your own pi survived > 5V once, not that all pi would.

On undervoltage (where there's no danger) - I've had pi zero working down to 2.9v

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Thu Sep 22, 2016 7:40 pm
by mattmiller
You have only proved your own pi survived > 5V once, not that all pi would.
Very true - but as long as I have a lucky Pi for the project - I'm fine with that :)

I imagine a few others will give it a go now and hopefully report in :)

Today - the Pi is still going after 12 hours!

Its down to 3.9V but still sending out 30 mins MQTT messages on mosquitto.org topic pizero4aa

And still flashing a LED

And I can still VNC into it and launch LX Terminal

So either today's set of batteries (which came out of same pack as yesterdays are a lot better or the official RPI white dongle draw much lower power than yesterdays RaLink

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Thu Sep 22, 2016 7:42 pm
by mattmiller

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Thu Sep 22, 2016 7:44 pm
by tpylkko
mikerr wrote:
On undervoltage (where there's no danger) - I've had pi zero working down to 2.9v
in that case, what about running it on three (or maybe even two) alkaline batteries?

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Thu Sep 22, 2016 7:52 pm
by FlexibleSigmoid
So TLDR version of the thread:

OP: "Going to hit myself in the head with a hammer, anyone think that's a bad idea?"

General Consensus: "Very bad idea indeed."

OP: "Tricked you all, already hit myself, now you naysayers look like fools!" <- Posted from the A&E

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Thu Sep 22, 2016 8:01 pm
by mattmiller
No you got that wrong - the OP was

"Has anyone bashed themselves over the head?"

to which many people replied
"Don't do it- you''l get hurt"
and
"I wrapped a rubber mallet in bubble wrap and it didn't hurt"

To which the OP replied
"Please read the question before answering"

and then later said
"Ok then - I'll try it out"
and later
"I seemed to have survived- I'll try again tomorrow but wear different glasses this time"

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Thu Sep 22, 2016 8:04 pm
by mattmiller
Oh dear - trouble :(

The WiFi dongle I borrowed was from the bedroom Pi which is used to relay old Sky+ handset IR codes to our SkyQ (NEVER get one of them BTW) box in the living room (using MQTT of course)

My wife is NOT happy at lack of remote control facilities - and I can't find the Ralink dongle to use instead ! :(

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Thu Sep 22, 2016 8:12 pm
by FlexibleSigmoid
There's a very apropos quote from the movie Tommy Boy about a T-bone steak, a cow and a butcher. But I'd probably get banned for posting it.

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Thu Sep 22, 2016 8:18 pm
by mattmiller
On undervoltage (where there's no danger) - I've had pi zero working down to 2.9v
mm - maybe I've come at this the wrong way then - we should be testing PiZero out on 3 x AA Alkaline and see how long they last

Maybe even 3 * AA Normal 1.5V ones as IIRC I think they do better at high current discharges than Alkalines

Need to get hold of some 3 x AA battery holders then.....

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Thu Sep 22, 2016 10:12 pm
by mattmiller
Well its stopped flashing the LED now and last msg posted at 22:57 volts = 2.9 so I think we'll call it a day at this point 14.5 hrs wasn't bad though :)

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Thu Sep 22, 2016 11:06 pm
by peterlite
If 4*AA does not last long enough and the piborg is a touch to much:
https://www.modmypi.com/raspberry-pi/br ... g-battborg
The Battborg with a cheap motorcycle battery should run your Pi for a week or two.

Plus you can ride the motorcycle to work. :D

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Fri Sep 23, 2016 7:20 am
by mattmiller
New thread on the 3 x AA experiement
viewtopic.php?f=63&t=160710

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Fri Sep 23, 2016 8:14 am
by daveake
Be aware that Lithium AAs start at about 1.84V, not the ~1.5V of an alkaline cell, so if someone does pop 4 of those in to your device then their Zero and USB device are going to see over 7.3V.

Primary Lithium cells do lose voltage pretty quickly under load, but over-voltage damage also happens quickly.

Dave

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Fri Sep 23, 2016 1:23 pm
by mattmiller
Ta for info.

I think I'm either going to be using 3 or 4 plain AAs. If the 3 x AA last 0.75 of the 4 x AA then its a no-brainer to go with them as not going to stress out anything and I won't get the RSPCP onto me :)

Re: Anyone tried 4xAlkaline AA batteries on PiZero?

Posted: Fri Sep 23, 2016 1:28 pm
by jamesh
mattmiller wrote:New thread on the 3 x AA experiement
viewtopic.php?f=63&t=160710
Please use new thread.