Topic: Advice for a remote weather logging station (other than the WS6006)

[Apollux]

I'm an architect and want to set-up an unattended weather logging station on a remote site that presently is off-grid. Has no power nor Wi-Fi, but cellular reception and enough solar radiation year-round. Also have a limited budget since this is for a hobby project. Some of the building design features will be heavily influenced by the weather conditions, so I need a record of the weather on that particular site during the entire year. Real-time monitoring is a Nice-To-Have but not a must. Accurate record keeping is the goal.

Already have a WS90 and a GW2000 running at home. Plan is to set-up some solar panels (reused from another project) and a portable GSM-WiFi modem on a rainproof housing to power and monitor the console. Call it the poor-man's WS6006 if you will. During concept testing it became clear that, if for some reason, the GW2000 losses Wi-Fi or power the data for that time period is gone for good. So started looking at consoles with built-in non volatile store (like an SD Card) and ended with the HP3500, HP2550 and HP2560 in my shortlist (The HP3500 was recently upgraded to support the WS90 while the WS6006 isn't yet compatible with the WS90 ).

By reading the manuals I see that HP3500 touts "Historical data preserved during power outage on optional SD card", but the HP2560 says you can (manually?) "Copy history data to SD card?". Is there a way to have the HP2560 save the data unattended? Or does the data get preserved inside the HP2560 inner memory and you only need to manually export it at the end of the data collection period?

Any insight would be much appreciated. Thanks!

[olicat]

Hi!

No, the HP25xxC (as well as the HP35xxC) automatically saves the current data of all sensors to the SD card at the configured interval as a CSV file.
There were always a few minor problems with the HP35xxC regarding the CSV data format and the supported sensors - but I have not yet verified this with the new firmware.

Oliver

[Apollux]

Thanks. The HP25/26xx family seems more feature rich, so the choice is made 

[olicat]

Hi!

Good decision.
Keep in mind that the HP2550C draws 500mA/5V while display is activated. With display off it needs up to 200mA/5V.
I don't know the power consumption of the HP2560C. It may even be marginally higher because there is an additional T/H sensor that has to be supplied with power. But it will probably be similar in the order of magnitude.
So it is not particularly energy-saving - you should therefore ensure that you have sufficient battery capacity at night.

By the way, there was already a project here for a self-sufficient weather station based on the GW1000 - maybe you can find it via the search.

add:
I found this.

Oliver

[Apollux]

Hi!

Good decision.
Keep in mind that the HP2550C draws 500mA/5V while display is activated. With display off it needs up to 200mA/5V.
I don't know the power consumption of the HP2560C. It may even be marginally higher because there is an additional T/H sensor that has to be supplied with power. But it will probably be similar in the order of magnitude.
So it is not particularly energy-saving - you should therefore ensure that you have sufficient battery capacity at night.

By the way, there was already a project here for a self-sufficient weather station based on the GW1000 - maybe you can find it via the search.

add:
I found this.

Oliver

  Thanks... That setup is beyond my technical level at the moment, but now you've set the project goal !

[Apollux]

On the topic of power, I could either go with a dedicated Solar Panel + Panel charger brain (with built-in USB power output) + Battery OR Panel with built-in USB output + Mini-power center with built-in battery. I see that EcoWitt / FineOffset is selling a mini-power center. Does anyone here have experience with that power bank?

[Rover1822]

I'm not familiar with that particular model, but , please understand that unit expects a regulated 5V , usually constant power (meaning not frequently dropping in and out). It might work off a regulated panel, you can be the guinea pig. In theory it will work  but, 6700 mAh (6.7Ah) at 5V (adjusted edit which is 33.5 Wh ), is nameplate, and you probably don't want to drain it daily below 1/2 that capacity. So if you draw 500mA , over 24 hrs , is 12000 mAh, and that unit will not make it even 1/2 day without charging. It gets confusing... I know

Oh, just in case, someone check my math

You have to size the panel and the battery correctly for use over long term with what may be extended periods of little to no charging. And that is the fun part, you obviously want to over estimate on everything

I have a similar setup for some of my security cameras, but I use like a 100W panel, and feed a deep cell marine battery. I have to do this as , like you , the camera is up 24/7 and sending data (not like one of those ones that is just motion activated and can use an internal battery and small solar panel).

Edit: Adjusted for my own bad math

 

[Rover1822]

I am intrigued by your project, for the remote off-grid power.

In another thread I describe the building of a small UPS unit based off of 18650 Li batteries to supply power during power outtages. But that is an ON-Grid solution as the DC voltage to the UPS is supplied by a standard AC USB adapter. You want to charge via Solar, so the , you have to also think of charge cycles.

https://www.wxforum.net/index.php?topic=43930.msg447176#msg447176

The concepts for you are relatively the same, it is the sizing of the solar panel, the battery selection (voltage , capacity, etc), potentially a charge controller for the solar to the battery, a voltage regulator off the battery to supply the power to your device.  And, most important.  the current draw (watts is better to work with for working this out, with different voltages involved) from everything you want to run .

This https://rovr1.com/wind/todayshed.gif  (image will change on the minute) is how I watch the power use, solar power, and state of my battery , using a WiFi XBee , for a different system, the one with the always on camera , motion detection LED flood, and , the overhead of the Xbee and monitoring.

What you need is something like that, in a neat package.  (I am going to look for an off the shelf system)

[Rover1822]

Yeah they are out there.

https://smile.amazon.com/Renogy-50W-Monocrystalline-12V-Controller/dp/B083K9H37W/ref=sr_1_1?keywords=50w%2Bsolar%2Bpanel%2Bkit&qid=1674064753&sprefix=50W%2B%2Caps%2C104&sr=8-1&ufe=app_do%3Aamzn1.fos.18630bbb-fcbb-42f8-9767-857e17e03685&th=1

Something like that, with a decently sized battery, marine deep cell group 24 or 27.
The controller is PWM, which isn't the best on using the available power (I use MPPT controllers), but should work, but it has USB 5V outs that come off the battery which you can use and simplifies things
Of course your actual amount of sun you get, your draw, etc , would determine the actual size, I went with 50W minimum, assuming you had a lot of sun.

I'm basing all of this on cost, and this is about as cheap as you can go category.

For just the power source... with a kit like that, you should be able to get to ~$200 US (you have to buy a battery)

[Apollux]

Thanks Rover,

I´m currently exploring these options:

A.- Bare minimum (12W). Cost around $75.00 + shipping

Mini UPS Battery Backup Uninterruptible Power Supply. Built-in 10000mAh battery. ($50).
5V 12W solar panel with USB DC output ($24)

B.- Room to grow (100w). Cost: around $250.00 + shipping.

YAARZAR 100 Watt 12V Solar Panel Kit
+ a locally sourced marine battery (I´m not looking forward to paying overseas shipping on a battery).

C. Something in between. Like the one you linked.

[Rover1822]

Plan is to set-up some solar panels (reused from another project)

I forgot that , you name plate values on that ?, for wattage (that one I really need) , Vmp , or just Vmax, or V  etc. If you have a panel, I can come up with another solution. Remove the cost of the panel , and it drops in price

But , it still , until we get a constant on power draw (in watts) , which , in your case , should be fairly flat line , I mean constant , so we can scale to meet the need.

[Rover1822]

The 2nd choice , is feasible, and would  work , but you have to buy a battery. So add , in the US, another $100
I think the first link is not usable for your intended purpose. (That being remote, not tended , and "OFF GRID" , the capacity is just not there.)

On the 2nd choice, it says USB somewhere, but very little detail, and you want that as a power out to your USB connected stuff as you have described. I would want more info on that, but I think the 100W solar in that kit would be sufficient, to charge a properly sized battery for your use.

This again, falls back to total draw, consumption of the "components" you want to power. I know there is the console, and then there is maybe this cell connection device. Would need total W consumption . Nameplate is fine.. the sticker on the units, voltage x amps on what they list. I "think", 100W  panel -- > PWM controller .--> walmart group 24 deep cell be quite OK on input , then the output side, you want that little controller box to have a USB out to power your console (although we can change that up going to straight to battery for higher voltage if needed) . If the little controller box does not have a USB output, then , you can buy a cheap automotive one and direct connect to the battery

I'm just looking at the cheapest, achievable , solution based on parameter given , unless I missed something.
If you have a panel, then we can look at that

[Apollux]

About the panels I already own, they came from solar power security cameras (the type that doesn´t transmit 24/7), so their output must be really small. They are rated for 5V 1.5A, I might as well discard them. I did order the 5V 12W ones from my previous post just to get my feet wet and start learning the ropes (waiting on that shipping).

A far as loads on the system, I already know the HP2560 console draws 5W ⎓ 1.0A * 5.0V
I need to revisit the site to check cellphone reception of different networks and then check their mobile hotspot modems. One candidate is the ZTE MF920U, it draws 4W and has a built-in 2000 mAh batttery the manufacturer says is good for 6 hours.

weatherspark.com has this to say about the site:

The average daily incident shortwave solar energy experiences some seasonal variation over the course of the year.

The brighter period of the year lasts for 2.0 months, from March 5 to May 5, with an average daily incident shortwave energy per square meter above 6.5 kWh. The brightest month of the year in Palmar de Ocoa is April, with an average of 6.9 kWh.

The darker period of the year lasts for 4.0 months, from September 6 to January 7, with an average daily incident shortwave energy per square meter below 5.1 kWh. The darkest month of the year in Palmar de Ocoa is October, with an average of 4.7 kWh.

Once I know for sure the modem model I´ll have max load number, but 10W seems a likely estimate.

Could also forgo the modem, treat it like a local storage logging station and base all the calculations on the 5w for the console.

[Rover1822]

Cool...

Those are useful numbers, but will wait until the dust settles. Sadly , I don't think your existing panels as described , will be of any use for your purpose.

I wish, I could tell you, just buy this, but , in reality , there are other factors to consider. I believe, your 2nd option link, with the 100W panel (and you purchase a battery) , will work  and sustain over periods of  darkness, or low light levels. 

But am I going to tell you to rush out and buy stuff. No. For the endeavor you are looking at, you have to get grasp , and I think you are getting it. Call this my disclaimer, LOL

I have experimented enough , with various panels, etc, that I can't give a definitive, just do this. Although , despite all that .... option 2 is the direction .