LiFePO4wered

[warp]

It might be interesting to add hardware like this in home automation ?

http://lifepo4wered.com/lifepo4wered-pi3.html

https://github.com/xorbit/LiFePO4wered-Pi

2016-12-15T20_35_06_599Z-IMGP8966_JPG_855x570_q85_pad_rcrop.jpg (122.12 KiB) Viewed 1016 times

[niceandeasy]

My two cents about this gadget...

It is a great solution for those who want battery or backup power to their Pi, without hassle.
But I wouldn't buy this.

Powering your PI through the GPIO connector is NOT recommended, however, it is claimed that they do it in a safe way.
Having a touch pad for turning my PI on and off freaks me out. I'd like to see a real clicky pushbutton.
It is supposed to be used with a LiFePO4 cell. The operating voltages of these are NOT compatible with regular Li-ion cells.
Would be good if the mode can be switched between LiFePO4 and Li-ion and maybe even LiPo.
Changing the battery while the Pi is powered by +5V-supply WILL damage the unit.
It would be good if the battery charge voltage can be set to the cell's storage voltage value. Powering a Pi after mains power failure until shutdown has been completed will only take a little time and power. By setting the battery's charge voltage to the storage voltage, the battery will last much much longer. Li-xxx batteries age the most when kept at their max or min voltage.
This gadget does not schedule regular battery tests and will not notify when the cell will no longer be able to live up to its task.

This thing is quite expensive. There are much cheaper USB powerbanks out there. Some of those USB powerbanks will switch on by a pushbutton, will power the Pi3, will detect the reduced current draw after the Pi3 has been shutdown and will turn off the output. If this is an always-on / ups setup, keep the cell(s) charged by using a 2-amp buck regulator which is set at 3.8 volts (Li-ion), for extended battery lifespan.
A simple py script in rc.local will take care of an automatic shutdown, triggered by header pin 5 (one of the i2c-lines), which will be triggered by some small transistors, capacitor, some resistors and a sense line to the buck charger input. Same header pin can also be used for re-starting the Pi when it would be shutdown and still powered, by just a simple pushbutton switch. And by attaching some transistors/resistors/capacitors to the powerbank's pushbutton, you can make it automatically switch on when the power failure is over.

All of my Pi's that don't use i2c have a pushbutton at pin 5 to gnd, and a py shutdown script. Very handy.

[warp]

# niceandeasy
you say : "There are much cheaper USB powerbanks " Do you have any links to offer ? Or montages easy to implement ?

[niceandeasy]

It's like I said: "It is a great solution for those who want battery or backup power to their Pi, without hassle."
So, if you are looking for 'easy to implement', I definitely recommend the LiFePO4wered.

Cheap generic USB powerbanks can be found almost everywhere. My Raspberry has been running on a LAB31 portable usb charger from "Action" store and on another one, which Idon't remember where I got it from. I guess, any USB powerbank with 2amp rating from a real store would be good. Just don't connect your pi (or any other electronic device) to a cheaper than cheap free international shipping chinese ebay clone crappy usb-bank.

I just wrote my opinion about the LiFePO4wered, I gave some options on how the makers could improve the device, and I gave some ideas and directions on how to create a similar device by yourself. For the details on those ideas and directions: use Google. If you're not up for that, by all means, buy the LiFePO4wered or another Raspberry-tailored battery-power-solution.

I cannot publish schematics, code and parts lists, because I don't have a working prototype. Currently, I don't have plans to create one. My Domoticz-pi, storage, esxi-server, router and switch are protected by an APC ups system.