Tempest Battery Voltage Range

This is good info. Is it possible to add this to a FAQ with a Tempest Battery label?

I have had my tempest about 3 days now and it has been hovering around 2.6V, all of a sudden this afternoon it rose to 2.8 . What is odd is that the sun is going down. so it looksl ike its at the top of the battery range

Turns out I had turned the unit toward the west last timeI took it down so it was catching the afternoon sun which is why it rose at the end of the day

Thanks for posting this screenshot. This confirms my Tempest is defective. It takes 4-6 hours to increase its voltage by 0.06+ in direct sunlight.

3 posts were merged into an existing topic: Tempest Not Charging

I just got my Tempest and installed it. The battery was at 2.58V when it arrived and
the vey next day after installing, on a sunny day with clear sky, it started charging all
the way to 2.75V and then it was overcast and the voltage dropped a little down to
2.71V I am wondering what is the maximum voltage where the battery is at 100%

It varies between 2.75V to 2.8V. IMHO, 2.75V is a full battery…Anything over that is a bonus.

Thanks, how long can it operate with a cloudy sky where there is no charging?

Great info below regarding your question

Another good thread to read…

OK thanks, the voltage dropped to 2.64v after a cloudy sky for about 3hrs.
I am getting network error in the App frequently and when I close the App
and restart it, the connection is back. Any idea what would cause this?

What do you mean by network errors ? The hub can’t send data to servers ? Your mobile app can’t get data ???

If you share a few more details we might be in a better position to help you.

3 posts were merged into an existing topic: Status Light on Tempest Hub

Station ID:15419
My battery voltage has been hovering around the 2.42 -2.38 range since mid-July. Is this a normal voltage?

Mine’s been up for about 2 months now, and voltage runs from 2.45v to about 2.58v - never higher or lower than those numbers. Interesting that some are somewhat higher in the 2.7v range. It’s never gone offline and never falls below 2.45v. Is this acceptable behavior, or should it be charging up more than it does?

I must be doing something wrong. We’ve had a solid spell of sunlight here for the past few weeks. My new Tempest charges up to 2.79 or so every day and then overnight drops off to 2.60ish.

Early models and some beta units had their battery levels way lower than the actual ones.
The max level is +/- 80% charge and the discharge is pretty low since you are really in the ‘thick’ of the battery. You have an almost flat graph during normal sunny days with a few little dips when you have a really dull grey day or rain. As you can see my max is 2.6V when you have clear sunny days and I dip to 2.4V in worst case. Last night I went from 2.6 to 2.58 …

The newer model charge to near 100% (near 2.7 -2.8V) but once the sun disappears your voltage dips quickly as you can see on many graphs posted here and that is perfectly normal. The battery quickly settles to a ‘rest’ value (+/- 2.6V) and from there starts to discharge if energy is asked. See ICWX post above that mentions David.
And from there you will see a normal discharge rate/voltage.
And remember that you need almost as much energy to charge from 80% to 100% as the first 80%. Those last 20% are a bonus but don’t really bring much to the life span of a full charge/discharge cycle.

Here is a typical graph taken from my NiCd battery pack (600 Ah-24V) when the system is switching on and off since it is estimated full and just keeps a trickle load. Each time the yellow line drops (cutoff of the solar array) you see the voltge drop from near 29V to it’s resting voltage near 28V and at the end you see it it go for stable rest value near 27.7V

Most of your Tempest are doing quite fine even if you see some differences (every single battery pack will be slightly different) but as long your unit charge normally and holds it charge, nothing to worry about. If you see it charges very slow or it drops rapidly into power safe mode, then indeed something can be wrong though not necessarily your battery. Might be regulator, solar panels …

1 Like

showing a graph of NiCd battery pack might be confusing, as the unit isn’t using NiCd as a power source.

1 Like

I purchased a Tempest a few weeks ago and mounted it in a location where it wasnt getting full sun exposure. After 5 days I lost connection with the tempest and no longer have the green flashing LED light. The voltage at that time was 2.48 volts which from the above seems like it should be operational. I’ve since relocated the unit to receive full sunlight, but have not been able to get the device powered back on (i.e. no flashing green indicator light…)

Anyone else experienced this?

I have an open ticket with WeatherFlow but have yet to hear back.

  1. is the switch still set to ‘on’ ?
  2. did you try a short push on the green led (yes it is a button). If so does it flash when you release it and connects again the hub?
  3. if a short push gives a flashing led but no connection to the hub, try a long push (more then 10 seconds to reset it) and then via the app in the setting use the replace Tempest to add it again.

Thanks Eric - Yes I had it set to ‘on’ as I understand the battery will not charge unless set to on.

I have not tried #2 or #3 yet - I did not know that the green LED was a button. I will give that a try and see if I have progress.

1 Like