Tempest voltage levels and power save modes, no rain detection etc

We are heading to winter (north side of the world at least) and our sun is giving less power.

Some Tempest devices are sitting in the shade most of the day, some don’t see any sun at all. In summer time this is mostly not a real problem but in winter … The battery can run the Tempest quite some time but without a few hours of sun (more than 300w/m^2) on a regular basis, it will deplete. And as it goes down, the power saving modes kick in to help it stay afloat as long as possible. We hear people say their Tempest doesn’t detect rain … but they didn’t look at the battery voltage. Once it is in mode 3 the haptic sensor is turned off completely, hence no rain detection.

This page explains in more detail the battery from the Tempest and the voltage levels.

Before opening a support ticket or a topic on this forum, please do check your voltage and siting of the Tempest. Often relocating it where it sees direct sunlight is enough to get it going again.

Compare the solar radiation graph and the battery voltage. The battery will really start to charge above 300w/m^2. If your solar radiation graph shows none or very short periods above that level, your battery will not keep up. Several days (cloudy days for ex) should not be a problem. Once the sun shines again, the Tempest will charge quickly to nominal again.

If you still feel it is more than a siting problem, do report here or you can contact customer support and we will help you out.


Is there a point voltage wise where the unit will not report at all?

Typically right about 2.3V since that is when the Tempest shuts down until it can get charged back up.

thanks… that puts my unit offline until it gets some sun… bummer… its the rainy season in Seattle… not sure it will come back online for a while.

i’ve seen comments of some who put a “lamp” at the solar panels but that seem incredibly inefficient and i don’t really want to take down and put up my system every couple of weeks (as that seems to likely throw off the integrity of my measurements if I have a periodic “bench” period)… curious if anyone else has some suggestions (other than wait for the in-dev power pack)?

I’m one who used a 250W lamp to charge up a Tempest. It was a very early field test unit which didn’t make it through that really dark time we had last winter. This was before the different power save modes and when I’m think the firmware was still running all of the debugging code.

It looks like your unit was charging fine in the summer. Is it getting some shade now with the sun low in the sky or is it just the cloudy weather?

Its a two part solar challenge…We havent had a nice cloud-free day in two weeks (pnw normal fall storminess) and i live in a forested area where the sun is above the treeline for maybe 4-5 hours daily (i have my sensor on the north end of a clearing centered between the trees). I would get a bit more solar panel sun-time if i lifted the sensor (its currently 2m or so above the ground) so maybe i could relocate it? To the top of my nearby barn. But thats also closer to trees on my property and may have more obstruction influences (always trade-offs). But if it gets me just a bit more power…?

I wondered if that might be the case. I figured we had somewhat similar weather but thought you might have a bit more fog. I happen to have a relatively clear southern exposure so my Tempests have been hanging in there.

1 Like

So if the voltage drops low enough to turn the tempest off entirely (2.33V for me) - will the tempest come back online automatically after enough sun? Or will i need to go through any rebooting / reinitializing process?

I can’t say I ever did nor did one of my Tempest go offline this way but since they come back after a reboot, I suspect they will come back online once there is enough juice in the batteries. Maybe someone with real field experience can tell ?

1 Like

Yes, it will come back online after enough sun. Assuming nothing is wrong with the Tempest, of course.

1 Like