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How much power does Homey use...? Homey on a UPS

RuudvBRuudvB Member
edited April 2017 in Devices
I recently bought myself a Varta powerbank to use as a UPS for homey. After my first unsuccessful tryout I concluded that a single 2.4A USB port did not supply enough power for homey to stay working.

After a very long search for a white USB Y-cable, it finally arrived. I combined the output of 2 USB ports 2.4A + 1.0A, expecting this to be enough. Unfortunately it turns out NOT to be enough... Homey restarts after pulling the 240V plug :(

Although I tested this about 15 min. after the new Homey 1.2.2 update it seemed that the powerbank did not have enough juice to keep homey working. What I also noted is that the 240V plug was quite warm, going to hot. Probably because of loading the remaining part of the batteries. The bank was about 75% full when connecting.

Does anyone know how much power Homey really needs in standby / idle mode?

Comments

  • 3-5 watt... So max 1 amp... So one hour Homey for every Ah...
  • bvdbos said:
    3-5 watt... So max 1 amp... So one hour Homey for every Ah...
    Sorry : 3 watt in idle... Measured with my plugwise-system and I know  others did the same with other measurement-methods...
  • Well I guessed that it would not be very much, 3-5 watt confirms it.

    The next question that comes up is why the total of 3.4 A would not enough to keep homey up-and-running on the powerbank? Pulling the 240V plug immediately changes the LED ring from rainbow (in my case) to yellow as when booting.

    And homey is booting because it is not available anymore when refreshing the settings page. Once rebooted, with the 240V plug in the power socket, all works fine again.

    Any UPS function does not work this way... Suggestions?
  • My guess: the voltage on the USB (so not the max possible current) is changing when unplugging... USB is voltage-controlled, not current-controlled. A sudden voltage-dip can cause disturbances on an electric device.
  • casedacaseda Member
    edited April 2017
    homey runs on 7watt when LED is on 100%, 7 (maybe 8) watt on 5v = 1.4 (1.6) amps... 

    just to let you know though,
    a lot of power banks are not designed for ups usage,
    and take a few (milli)seconds of time to switch from charging, to output.
    or when charging is stopped, it sometimes also turns off the output for a few (milli)seconds
    (milli)seconds can be enough te let homey reboot :smile:
  • anneanne Member
    I have Homey connected to the 2.1 A USB port of an 'Xtorm solar charger'. I can leave it unplugged from the mains for hours, no problem at all. I guess it depends... Not sure on what though ;) It seems that at least some powerbanks can deliver uninterrupted power. 
  • Homey uses approximately 1.6 - 2  Watt  idle without LED ring. 
    it varies from 0.29 A to 0.35 A. 
    Starting Homey it uses about 0.92 A / ~4.7 Watt at 5.12 Volt from the factory USB Adapter.



    Tuning the default LED Spectrum on at 100 % raises the consumption to 0.92 A / ~4.7 Watt.


  • anne said:
    I have Homey connected to the 2.1 A USB port of an 'Xtorm solar charger'. I can leave it unplugged from the mains for hours, no problem at all. I guess it depends... Not sure on what though ;) It seems that at least some powerbanks can deliver uninterrupted power. 
    Have you also tried it as UPS?   So with the powerbank being charged, while the Homey is connected, and then pull the charge plug?
  • caseda said:
    homey runs on 7watt when LED is on 100%, 7 (maybe 8) watt on 5v = 1.4 (1.6) amps... 

    just to let you know though,
    a lot of power banks are not designed for ups usage,
    and take a few (milli)seconds of time to switch from charging, to output.
    or when charging is stopped, it sometimes also turns off the output for a few (milli)seconds
    (milli)seconds can be enough te let homey reboot :smile:
    I guessed something like this, a dip in supply just a few milliseconds is probably the issue. Not the total amps which I already ruled out form the spec's of homeys power consumption as stated by other users above.

    Quite cynical though, normally I buy all type of "unknown" brand products. In this case, for UPS purpose, I especially chose a VARTA brand product....

    Now I have it all in white color, looking great in my living room; just not working.... :(

    It would have made such a practical solution when adding more devices. Just take homey along to the new device, install it and afterwards put homey back again. All of this without restart or interrupting already built mesh networks.

    Does anyone know a powerbank that will function as a UPS 100% certain?
    Oh, and for sale not a new VARTA powerbank :)
  • RuudvB said:

    Oh, and for sale not a new VARTA powerbank :)
    not = now
  • MarcelKuijperMarcelKuijper Member
    edited April 2017
    i cant help my self wondering why u want to put homey behind an ups? u wont have power at your lights / tv / hifi anyway when the power goes down?
  • RocodamelsheRocodamelshe Member
    edited April 2017
    RuudvB said:


    It would have made such a practical solution when adding more devices. Just take homey along to the new device, install it and afterwards put homey back again. All of this without restart or interrupting already built mesh networks.


    @MarcelKuijper
  • anneanne Member
    @Priknr1 yes (of course ;)), it makes Homey mobile/portable, allowing me to for instance capture wireless commands up close, re-pair a wallswitch without having to take it off the wall, etc., exactly as @RuudvB suggested. 

    I don't know how the constant (trickle) charging affects the powerbanks lifespan, probably kills it over time... 
  • Priknr1Priknr1 Member
    @anne
    Well maybe the lifespan maybe goes from 10 years to 5,  whatever :P

    Why I asked, is because I read that, when disconnecting the powercable from the Powerback, this sometimes also results in a power dip at the 5V output of the powerbank, which than results in a restart of homey.

    But in your case, no powerdip, and not restart of homey as soon as you disconnect the charger from te powerbank?

  • anneanne Member
    edited May 2017
    No, at least evidently no powerdip Homey can't handle  :) <span>:+1:</span> 

    So it is possible at least. 
  • Does anyone know a powerbank that will function as a UPS 100% certain?
    Oh, and for sale not a new VARTA powerbank :)
    I am using this one as a UPS for Homey already for a year without issues.
  • RuudvBRuudvB Member
    RamonBaas said:
    Does anyone know a powerbank that will function as a UPS 100% certain?
    Oh, and for sale not a new VARTA powerbank :)
    I am using this one as a UPS for Homey already for a year without issues.
    Great! So your sure there are no power dips? If so, I will order one today!
  • RuudvB said:
    Great! So your sure there are no power dips? If so, I will order one today!
    Well, Homey keeps running if I disconnect the mains, so no.
  • tunftunf Member
    looks good, my "kruidvat" powerbank is working for hours but drains down and cannot charge and discharge, the one you mentioned can do this so it is some kind of ups?
    I've some kabels to also power my router so with 2 of them i'm able to alert me and send alarms with my battery door/ motion detectors.
  • RuudvBRuudvB Member
    RamonBaas said:
    Does anyone know a powerbank that will function as a UPS 100% certain?
    Oh, and for sale not a new VARTA powerbank :)
    I am using this one as a UPS for Homey already for a year without issues.
    Just to let you all know, mine arrived today. It works perfectly as a UPS like Ramon suggested.
  • I just have Homey connected to a APC UPS and working good 



    i cant help my self wondering why u want to put homey behind an ups? u wont have power at your lights / tv / hifi anyway when the power goes down?
    True, but all local things keep working like z-wave :) 
  • @lubbertkramer happen to have the same UPS for my NAS; but does not qualify for walking around with Homey....
  • cbhcbh Member
    edited September 2017
    After this epiphany regarding the diversity in use of powerbanks I've read this post with joy.

    @RamonBaas:
    Just a thought:
    How does the RAVPower unit affect power consumption?
    Like, if the charger is inefficient, the cost could increase to something really bad :-(

    And thanks for sharing all the knowledge, all of you - great community!

    Add:
    What type of cable is running from the charger itself to the powerbank?
    have to pull the cable through a small hole in a wall (a standard USB-plug is too big - have to strip some of the plastic around the plug to get it through)...
  • cbh said:
    After this epiphany regarding the diversity in use of powerbanks I've read this post with joy.

    Add:
    What type of cable is running from the charger itself to the powerbank?
    have to pull the cable through a small hole in a wall (a standard USB-plug is too big - have to strip some of the plastic around the plug to get it through)...
    I use the standard 50cm cable that came with the power bank; works very nice no problems there. I guess you will have to tweak some USB cable to get it through a small hole... That, in case the micro-USB connector is too large for your hole.
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