Battery power supply/portable UPS ideas for hub & a tablet I

Continuing the discussion from A way to use Sky & Air on an RV or as a semi-mobile unit?:

I’ve been thinking about ideas for a good long term battery power supply/portable UPS for my hub and a tablet for when I’m camped somewhere. @SLOman used a 3350mAh battery and got a full 24 hours running just the hub.

I want something I can hook in to USB charging port while also powering the hub and a tablet. This way I can use an AC power supply or one running off of 12V. I was concerned that maybe the hub current was too low for my Anker Astro E3 Ultra Compact 10000mAh Portable Charger I purchased in 2013 might be too low for the battery to stay on supplying power but it appears to work fine. I would prefer a battery with a manual power switch where it won’t power down until the internal battery is depleted.

If my very cheap USB power meter can be believed, the hub only draws around 0.08A or about 0.4W. This seems extremely low to me but if it is true, that is awesome. Charging my battery pack draws only 1A so I was concerned about hooking a tablet to the battery and then having the tablet drain the battery pack. I ran a test last night where I setup my Galaxy Tab E near the hub, installed the “Keep Screen On” app and enabled it and set the brightness to dim. Starting with about 65% SOC on the tablet I plugged it in and left it. This afternoon the backup battery was charged to 100% and so was the tablet. It looks like it will work just fine. :smile:

FWIW, in my research so far it appears that many USB portable battery backup devices are removing the pass-through charging option due to heat buildup in the battery, thus shortening the battery’s life.

Now I just have to come up with a screen for the AIR unit that is easily mountable on my RV and so it stays dry and gives accurate readings.


FWIW, running just the hub on my 10,000mAh battery (37Wh) it ran almost 4 days. It appears that the 0.4W draw I measured was about right. 37Wh/0.4W/24h = 3.85 days.

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Has anyone plugged their Tempest wifi hub into a kill-a-watt to measure its typical power needs? I am thinking of providing back-up power for it. It probably does not need much.

I moved your post here as it relates to what I posted above. While this was with a SKY+AIR hub from the first generation, I’m sure the power demands of the Tempest hub is substantially similar. You could use a typical UPS on the AC side of things with an increase in power demand while due to the extra conversion.

This thread has some figures.

Due to the difference between Gary and my figures I bought another usb meter and it did read higher current than my first meter. So use Gary’s figures in preference to my first attempt.
cheers Ian :slight_smile:

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