I have trouble when running the Shelly H&T when using the USB power base.Under USB power the connection is intermittent at best:
On the left under USB power, after the second spike I gave up and reinstalled a battery again. Same location, so it is not closer to the hub. I set the Shelly to external power in the web interface and am also specifying ac_power in the Shelly discovery script.
Anyone have the same or different experience? Any idea what the issue could be?
Thanks
Did you get anywhere with this?
I’m seeing my H&T’s die when the battery gets to ~68%, so was considering getting the USB power base… but for the money and (perhaps) less reliability, I’m not sure whether to keep with these or go a different route…
I haven’t tried the USB base since, but there have been numerous changes made in the Shelly discovery script I have been using that mention ac_power for the H&T. I’ll try again and will let you know.
Nope, the problem is still there (the spikes are where I switched to the USB base at first, the second I unplugged and replugged the USB cable because I wasn’t getting any new data from the device, but then the temperature didn’t change enough for the Shelly to do that):
Other things I don’t like using the USB base:
It does generate some heat that raises the reported temperature by ~ 1 degree
Without the battery the Shelly is so light that it won’t stand straight on it’s base.
So I am going back to battery.
Hmm… interesting, thanks!
I have a support case open with Shelly at the moment… my batteries are dying “too soon” (in my vague opinion)
A recent battery died at 71% - that ran for ~2 weeks 
, so I am NOT impressed with that…
They are reporting that it is a firmware issue (I updated it ~1 or 2 weeks ago when I changed batteries), but that isn’t clear whether “70%” should actually be “0%”, (and a 2 week battery life is to be expected)
OR
Whether the device is using too much power
This particular sensor is at the far end of the wifi signal, and in a room whether temp (& humidity) change fairly often, so I think this one is particular “busy”, but even so… 2 weeks! Other sensors are definitely lasting longer, but I really don’t like the idea of using 1/3rd of a battery’s capacity 
I’m even thinking of getting an external rechargeable AAA battery pack and wiring that in… looks terrible, but for the money I’ve spent on sensors, I’m not wanting to spend that much on batteries!
So… apologies, I’ve hijacked your original question and I don’t have an answer for you 
From the shelly.cloud shop :
Shelly H&T has built-in modules for Humidity and Temperature and is the world’s first Wi-Fi Humidity & Temperature sensor working over 1 year on battery.
Big difference with 2 weeks.
That’s alright. I confirmed that the problem still exists, and that my decision to give up on the USB base is still the right one to make. I am not keeping track how often I change batteries, but it is definitely more then 6 months, so your 2 weeks are definitely not good™
humm… i have two shelly H&T and the longest the battery lasted was 10days. Not good.
I switched to usb but havent experienced any issues.
… time passes …
OK, just thought I’d post an update from my experiences …
Battery life… I don’t have enough evidence yet, but my “slap my forehead” moment was when I looked at the batteries I was using. I’d bought a different battery from a different shop and was surprised when it lasted much longer than the others.
Compared the two… and the difference was… mAh 
- I’d just assumed that all “CR123” batteries were the same. Nope. Seems obvious now.
Secondly, I’ve noticed that the firmware updates have recently added some more functionality, so I just bought a USB power base to try out and see if it works / firmware handles it now - so far (~1 week) it seems to be working ok. (I’m not seeing any glitches)
So, my current plan is to use the USB base(s) where they’re near a power source and use larger mAh batteries in difficult places (ie the bathroom). I’ve even purchased a 16340 (LiPo) rechargeable battery to see if that works.
Hate to awaken this thread, but did the 16340 work or cook the sensor?
They work fine… in fact, I’ve bought loads more (16340s) and I’m using them everywhere now.
The only slight issue is that a 16340 is +1~2mm longer than a CR123 so they’re a little tight inside the H&T’s (& Shelly Floods), but, they work fine.
I haven’t paid attention to how long the batteries last, but they’re lasting for weeks / months (& obviously they’re rechargeable), so it’s fine by me.
Getting back to the original issue, I have a one H&T powered by the USB base (from a wall socket) and it’s fine - no spikes at all… ever (I think), so maybe the OP’s issue was firmware / dodgy base unit.
Weirdly, the USB base always reports ~85% power… I vaguely recall there was something in the settings about whether a USB powered base was in use, maybe that does something… not checked.
But… 16340s are the way to go if you want batteries. 