WXforum.net

Weather Station Hardware => Weather Station Pictures => Topic started by: taylormia on October 04, 2018, 10:59:39 AM

Title: VP2 in Omaha, NE
Post by: taylormia on October 04, 2018, 10:59:39 AM
Here's my Davis VP2 with 24hr FARS located in the backyard. Not many siting options considering the urban location, HOA rules and most importantly the WAF  :lol:

(https://i.imgur.com/HO5Jgnr.jpg)

Here are my websites. I'm using weeWX 3.8.2 with reports uploaded to WU and PWS every 5 min. The personal website uses a weather34 template that updates every 30 seconds.

https://weather.sathy.us
https://www.wunderground.com/weather/us/ne/omaha/KNEOMAHA440
https://www.pwsweather.com/obs/KNEOMAHA440.html
Title: Re: VP2 in Omaha, NE
Post by: bchwdlks on October 04, 2018, 02:09:10 PM
What time of day was your picture taken?

It might be an illusion, but it looks to me like the solar panel is oriented so that it is not getting very much direct sunlight. Based on the sunlight on the pine tree and the mounting post, it looks like the side of the post away from the anemometer would be better.
Title: Re: VP2 in Omaha, NE
Post by: CW2274 on October 04, 2018, 03:19:58 PM
It might be an illusion, but it looks to me like the solar panel is oriented so that it is not getting very much direct sunlight.
Good catch. It looks like you'll be eating CR123 batteries unless you 180 the ISS as the super-cap will never charge properly, the batteries for the 24hr fan won't charge properly as well (if you're using them), as well as the fan not running at full power.
 
Title: Re: VP2 in Omaha, NE
Post by: taylormia on October 04, 2018, 03:26:31 PM
The pic was taken around 7am and that's why you see the sunlight on the east side of the post. The post is too close to the fence to face the solar panel south and get good direct sunlight. The solar panel is facing West in the pic...which provides the best of my options for direct sunlight ...given the post location. I have noticed that from 10am to 5pm the solar panel gets direct sunlight for 3-4 hrs and indirect sunlight the rest of the time. I have had no low power warnings since installation.
Title: Re: VP2 in Omaha, NE
Post by: CW2274 on October 04, 2018, 03:43:13 PM
Hopefully that will do. You may run into problems if you have extensive overcast days, something to watch for.
Title: Re: VP2 in Omaha, NE
Post by: taylormia on October 04, 2018, 04:19:53 PM
I understand the concern about getting a good charge. Is there any way to check the voltage of the super-cap?
Title: Re: VP2 in Omaha, NE
Post by: ValentineWeather on October 04, 2018, 04:28:07 PM
The main thing is have the larger solar panel pointing at sun for longest period throughout daylight.
This is the panel that powers the fan and recharges the 2 batteries that keep fan running throughout night into the next day. If real cloudy and snowing you may go long periods before batteries (fan) get recharged.   
There is no alarm or warning when the fan batteries are low.

Only the ISS transmitter which uses the small panel gives a low voltage warning.   
The small panel only use is recharge the capacitor which powers the ISS transmitter and takes an hour or two of sunlight for full charge lasting throughout the night.

The small battery inside the ISS is backup for capacitor only used after extended no sunlight periods where the capacitor gets drained from lack of sunlight. 
This same battery is what gives the low voltage alarm and is not rechargeable. If you get the alarm the battery needs replaced.
Title: Re: VP2 in Omaha, NE
Post by: taylormia on October 04, 2018, 04:36:59 PM
Thanks for that explanation. Is there a way to check the voltage of the capacitor that powers the ISS to see if it is being charged sufficiently? I understand that there is no way to check the charge on the FARS fan batteries.
Title: Re: VP2 in Omaha, NE
Post by: Old Tele man on October 04, 2018, 05:16:30 PM
Thanks for that explanation. Is there a way to check the voltage of the capacitor that powers the ISS to see if it is being charged sufficiently? I understand that there is no way to check the charge on the FARS fan batteries.
Not easily...the supercap is under the white plastic cover (soldered to PCB) inside the ISS.
Title: Re: VP2 in Omaha, NE
Post by: ValentineWeather on October 04, 2018, 05:25:51 PM
Thanks for that explanation. Is there a way to check the voltage of the capacitor that powers the ISS to see if it is being charged sufficiently? I understand that there is no way to check the charge on the FARS fan batteries.

I'm not aware if there is. Failures generally start draining the batteries prematurely way before they should die.
Say you get a low battery alarm, and need to replace again within a few weeks you may have a bad capacitor. Inspect and look for signs of leakage.
I've personally never had one go bad, with 8 units running. 
Title: Re: VP2 in Omaha, NE
Post by: CW2274 on October 04, 2018, 06:03:04 PM
I understand that there is no way to check the charge on the FARS fan batteries.
Sure, you can always pull them out and slap a multi-meter on them, they're just 3v "C" cells so you'll know.