I wrote a webCoRE piston that pings a mesh WiFi point every 5 minutes. If it's there, it has power. If not, move on to pinging my sprinkler controller and printer. If all three aren't available, hit the Hubitat shutdown URL.
My computer, monitor, modem, router, network switch, and hub are all on the backup. With all that stuff, I only have about 10 minutes of power. I probably should have gone bigger (duh!), but it really shouldn't be a problem. I just want my computer and hub to be shut down gracefully and everything else to be protected from surges mostly.
That is the board I am using. It works great, small I connected it in series with the HUB power supply, I added a switch on the box so I could cycle power without pulling any of the connectors.
Oh and I soldered the input and output power to the board as the connectors were too fragile.
I recommend this unit from Talentcell. It will run for hours easily because it's not trying to convert DC batteries to AC where you lose a ton of power in the conversion. Just plug your hub into one of the USB ports. Done.
@JohnRob Actually no. Most devices actually operate on DC current. Those wall warts most devices come with actually convert AC to DC for the device. That Talentcell UPS actually has adapters so you can plug in 12v devices directly into it, as well as 5vUSB ports. My hub is plugged in to the USB port, and I have a wireless bridge plugged directly in to the 12v port. It's a very simple and effective solution.
I see what you are saying. THe little UPS I have takes in 5V and outputs 5V. But it has an internal switcher to boost the 18650's 3.7 to 5V.
I'm pretty sure the TalentCell has switchers** to create the 5V, 9V and 12V from whatever the battery supplies. The switchers not only boost or drop the voltage, they also regulate the voltage so the outputs stay constant as the batteries drain.
Having said that I've heard good things about the Talent Cell and it seems to be a very good option.
I don't trust using any unattending device charging on lithium battery (especially mine will be in the hot attic), so I use this more trustable Meanwell PS (got it from Warehouse for $27) with SLA battery and have the AC loss output to trigger a Zen17. It also powers my other 12V hardwired devices and security sensors (can also use cheap 12V to 5V stepdown to power 5V devices if needed). (Hub is using regular Cyberpower UPS along with other essential equipments)
Regarding USB UPS’s, you will find that all 12v to 5v buck regulators use switching power supplies. Thus the conversion generally goes 12v DC > 12v AC > 5v AC > 5v DC using high frequencies to keep the conversion efficient. I doubt anyone uses linear regulators any more as they are so wasteful. Just as a FYI...
Little UPSs on my HE, Lutron, Hue hubs, each of my network switches and nodes, ONT, computers, playstation, etc. Just long enough to have the auto transfer switch start the generator and kick over. Most of my zwave and zigbee devices would go offline for a min or so.
I know that a widespread power outage is likely to take down cable Internet providers such as Comcast. They need commercial power to run their banks of servers. However, if you have a more localized power outage such as a blown transformer or downed line in your neighborhood, you might lose power without losing Internet. However, you would have to have backup power for your cable modem and router.
One thing I like about Hubitat is that it can still access battery powered sensors as long as it has backup power. It would be nice if it had its own battery backup like the Smartthings ver. 2 hub. Since I have a UPS to provide power for my cable modem, router, Hubitat, and Hue and Lutron bridges, it is not a big deal. I know my Hue and Lutron lights require commercial power, but at least the hubs and bridges will stay up long enough to shut them down elegantly.
Good point. ISPs definitely need power to run their servers. My experience with ISPs (not Comcast specifically) is those tend to be in tier 3 or tier 4 data centers. What gets them is the last mile - in an HFC plant there are often a couple active devices hanging off the node. Those active devices need commercial power. I don't know specifically what Comcast does but other providers have battery backup on the pole (if they have aerial plant) . But after a couple hours that goes down (sooner if they have not kept up with battery maintenance). During a prolonged outage they will stick a generator at the bottom of the pole and run the power supply from that, but it's not an ideal situation and they will usually try to prioritize the generators they have by powering critical customers first.
In a localized power outage we may be just fine (as you say assuming our cable modems are powered) but if the local outage takes out the HFC power supply and lasts longer than battery backup, we may find ourselves without service. Areas with aerial plant (as opposed to underground) tend to suffer more, for obvious reasons.
FTTP plants (as opposed to HFC) have fewer active devices and are generally less susceptible to active-device issues like suck-outs, loss of power, level balancing, etc.
I agree - HE can still access battery powered devices, but I wonder what happens when all those line-powered repeaters shut down I haven't tested this and would prefer not to. I have enough ZWave angst as it is!
I wonder if there's a PowerChute (or equivalent) for HE?
It's convenience for people who don't use UPS for computers or devices, and battery powered sensors make sense as they will be installed everywhere that might not have power access and cleaner look, but for a mesh hub that can be placed anywhere that has an outlet and network, I'd rather to have my UPS doing it along with other equipment than having one more device with rechargeable battery to maintain (it's fine if it's optional and I can simply take it out if not needed)
Does anyone have experience with what happens to a zigbee or zwave mesh when it suffers a brief loss of power? I have my hub, all of my internal network nodes, and my ONT all on UPS and the house on generator, but the switchover to generator and back takes a few seconds. Just wondering what the effect will be on Zigbee and ZWave devices during that brief period.
If you hub is on a UPS, that is good. During a power failure, your battery powered sensor will remain online as your radios will remain online. However, mains powered devices, including repeaters, will go offline, at least momentarily and do a soft reset. Once the power is restored, the mesh should recover, but I cannot tell you how long that might take. It is possible that some mains powered devices might not come back without intervention, but you might get lucky and everything will come back normally. Hopefully, power outages are not a frequent occurrence.
If you have any "mission critical" devices, you might consider small battery backups for them as well. Remember that when the power comes back on, there can be power surges that might damage some devices.
I haven't tested this and would prefer not to. I have enough ZWave angst as it is!
