Author Topic: Powering PiCap  (Read 1345 times)

Offline TastyHamSandwich

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Re: Powering PiCap
« Reply #15 on: March 11, 2018, 09:04:48 PM »
https://www.tindie.com/products/xorbit/lifepo4weredpi/
https://www.tindie.com/products/xorbit/lifepo4weredpi3/

Depending on which version you get, it's about $35-$42. The guy behind them, Patrick, told me he has a new version on the horizon, the LiFePO4wered-Pi+, that will just use the one base model for any given model of Pi, but has modular battery options. He told me it's available to business users for evaluation right now, but not general release.

Offline algerdes

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Re: Powering PiCap
« Reply #16 on: March 12, 2018, 12:16:23 PM »
Have you had the chance to see how long the charge cycle takes?  Under what load, and what power input?

Offline TastyHamSandwich

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Re: Powering PiCap
« Reply #17 on: March 13, 2018, 09:36:39 AM »
algerdes,

I haven't been able to perform any stress testing in any capacity, yet. This is definitely on my agenda, though, as I have to provide a comprehensive report on every aspect of this Pi, configured as it is.

Things I plan on testing are:
-Length of charging cycle, 18650 battery
-Length of charging cycle, 14500 battery

-Length of battery life when idle, Pi B+ (14500 battery)
-Length of battery life under load, Pi B+ (14500 battery)

-Length of battery life when idle, Pi 3 (18650 battery)
-Length of battery life under load, Pi 3 (18650 battery)

All power input has been supplied with a 5v, 2.5a microUSB power adapter, provided by CanaKit. I use a separate LRS-350-12 from Meanwell for powering the PiCap, and likely will have something similar for the FPP itself, in 5v configuration, once I have an enclosure to put everything in.

Offline algerdes

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Re: Powering PiCap
« Reply #18 on: March 13, 2018, 10:18:46 AM »
My parameters are:
Sun - Thur:  Power is on from 4:45PM till 9:15PM. (5 1/2 hours)
Fri - Sat:  Power is on from 4:45PM till 10:15PM. (6 1/2 hours)


So the charge will have to be good within these times.  (Use 5 hours as the "standard".)


The length of time the unit must hold the FpP up would be how long it would take to shut each one down.  If the "power out" routine can take control the moment the power does go out, plus a "fudge factor" in case this is only a temp out (say someone trips over a plug), then this could be 10 to 15 minutes.


If the "power out routine" has to wait till a sequence finishes, note that I have a couple sequences that are 7 till 10 minutes long (medleys), the amount of "up time" would have to be until the sequence finishes, plus the amount of time it takes to properly shut down the FpP.  This could be 20 to 25 minutes.


So, in a nutshell:
Must be able to fully charge in 5 hours.
Must be able to keep the FpP alive for up to 25 minutes.


Then there are the possibilities of short cycles for charging.  I'll not get into them at this time.




Offline bpos

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Re: Powering PiCap
« Reply #19 on: March 24, 2018, 09:11:22 PM »
If the power goes off so will your lights, so why bother keeping the Pi running?  There is a work being done right now to minimize the potentail for corruption to the uSD when power goes off.  I believe those changes will be in place before show time comes around this year.  That being said.  I Have been running FPP since the very first version and have never lost a uSD to corruption.  In 2016 I ran 5 Pis in my show, in 2017 I had 10 Pis in my show.  Would seem a lot more cost effective to just have a second uSD ready to go if it is some type of insurance you are seeking.  Just my 2 cents.

There might be another way to avoid a second power source and that's by adding a one way diode in line of the pixel power to avoid back feeding the Pi player (via PiCap Voltage).  I added a switch to the PiCap voltage in line but the problem is that it gets over ridden when you plug in pixel power.

Have not tried the diode yet.
I am running 100% battery power with lipo 5000 mah and I can tell you that if you want to go total battery power then you might want a small pixel line because it sucks that battery dry in 10min.

Offline algerdes

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Re: Powering PiCap
« Reply #20 on: March 24, 2018, 11:39:43 PM »
I purchased one of the battery backup units for the RPi. (Thank you for the lead!) 


In our testing, the battery takes approximately 2 1/2 hours to charge from depleted to full charge. (The power is on for a minimum of 4 1/2 hours so we are good there.) It holds the RPi up for a bit more than an hour. (See next paragraph.)


This works beautifully with my scenario.  I'm setting my sequences to end approximately 45 minutes after the gates close.  (9PM Sun - Thurs, 10PM Fri & Sat.)  So, even on those days when the park power is pulled at gate closing (no one left in the park), the Pi will continue until reaching the "shutdown" command.  If we get a visitor just before gate closing, they still have 45 minutes to get to the show, watch it, then move to the exit. 


With the additional work being done to prevent the FpP from corruption, we should be covered.   :)
Also, with the new FpP software, perhaps I can get a "shutdown" performed as soon as the power goes out, without having to set a time in FpP for it.

Offline TastyHamSandwich

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Re: Powering PiCap
« Reply #21 on: March 25, 2018, 11:24:01 AM »
algerdes, is it the LiFe-PO4wered-Pi that you bought?

If so, if you kill power to the RPi, it can easily be configured to shut down after such an event, either immediately or after awhile. Should just be a couple two or three registers you need to set. PM me if you need any help, I'll be glad to provide it.

For my power needs, I've got a Meanwell 12v porividing input power direct to the PiCap, and through an 'Input 12v>5v MicroUSB' converter, power the RPi's LiFePO4wered-Pi3 off the same PSU, rather than adding a separate dedicated 5v supply.

-Tasty

Offline algerdes

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Re: Powering PiCap
« Reply #22 on: March 25, 2018, 01:16:01 PM »
Yep.  That's the one! LiFePO4wered.  Nice unit.


The question is, does FpP have this built into the code yet? 

Offline TastyHamSandwich

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Re: Powering PiCap
« Reply #23 on: March 25, 2018, 05:39:06 PM »
Mmm, no, I don't believe so. Though the software plays nicely with FPP so long as you're using the new beta image based on Stretch, not FPP 1.8 & before, using Wheezy.

Offline algerdes

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Re: Powering PiCap
« Reply #24 on: March 25, 2018, 07:31:46 PM »
The kicker here is the ability to tell FpP that power has been lost, and to run the "FpP shutdown" sequence.


Similar to the UPS monitor signal on a protected Personal Computer.  When the UPS reaches a certain power level, it tells the computer to run its shutdown sequence, saving open files and turning itself off.


This scenario would be perfect!

Offline TastyHamSandwich

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Re: Powering PiCap
« Reply #25 on: March 26, 2018, 09:07:59 AM »
Aye, it does exactly that, unless a standard 'init 0' / 'sudo shutdown -h -P now' shutdown command isn't what you mean.

The LiFePO4wered-Pi will do a safe shutdown by either touch-command or when power criteria are met (battery voltage low, or time since loss of external power - set this to 0 and it will perform a safe shut down immediately upon detection of input voltage loss.

Offline jholmes

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Re: Powering PiCap
« Reply #26 on: March 27, 2018, 11:51:46 AM »
I think the previous poster intended to have FPP run an actual series of FPP sequences to "Shutdown" their show.
Instead of the typical Sudo Shutdown -H, I would suggest you run an event or script (FPP -whatever...can't remember the command). Then that event/script can stop your show, play whatever end-sequence you need, and ultimately shut down your Pi.


Would need to be quick though, cause if the battery is trying to shutoff, I wouldn't think you have much time.

 

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