I’ve moved both solar nodes into the house for now. Heat is a real problem with this setup especially if they get 5+ hours of direct sunlight like they did today. It was 110F in there based off the Nexus 6 temperature sensor. 85F outdoor temp. I’m going to have to figure out a way to draw out the hot air with some kind of venting without letting water in.
As it is the 24,000 mAh solar battery pack is flashing all lights so it is probably down to its last 24 hours of operation. 6 days running without electricity isn’t bad. Especially as one could use a car to recharge the battery pack to full power again for another 6 days of solar work.
Heat is a real problem with this setup especially if they get 5+ hours of direct sunlight like they did today. It was 110F in there based off the Nexus 6 temperature sensor.
Have you considered using a peltier cooler under the solar panels to keep the solar nodes cool? Alternately, you could use the heat created by the panels to drive a peltier which powers a small muffin-style fan to blow air across the nodes, keeping them cooler.
This is a very simplistic version, but should give you some ideas:
With enough solar panelage, anything is possible. Power consumption on that might be - just guessing – 10x just the GTM?
What I’ve been doing is increasing the size of the case. The HF medium “Apache” seems to be nominal now, the small ones were just not big enough. I leave the foam insert in based on the fact that it takes heat to warm the air longer to work it’s way through that than through plain ol’ air. If the medium HF case isn’t big enough, get the large is my plan. However I use external panels, so don’t need the clear case.
Sorry if I missed it but I’m curious if you have tried omitting the phone or Bluetooth connected device? In my experience the GTM will still accept and relay messages fine although the light flashes as it is looking for a paired device. I haven’t tested it but I’m guessing this could save you the power consumption of the phone in your very nice project! My apologies if this was covered already!
I’ve put the weather relay nodes in my attic at the windows. With the solar panels pointing out the windows and with the rest of the box lid ajar I’m hoping the heat will not get to be too much. I’ve got the phones in the nodes to be able to positively confirm messages. I’ve not done any testing with the phones not connected.
With the phones attached people can ping the nodes to test their own GTM devices and at least get a positive response. But I can see that I can probably be much better off with just a solar panel and a GTM in relay mode that gets recharged during the day.
You can still ping and message a node that is paired to a device even if the device isn’t currently paired to the GTM. The GTM will also send message confirmation even though the device is not currently connected via bluetooth. The GTM does consume a lot more power when it is seeking to pair to a device though so I’m not sure it’s worth it.
Right. So my current solution with the mesh units in the attic is to keep the paired phone on the 2nd floor right below the GTM. This allows them to maintain the bluetooth connection to the GTM and not powered off the same battery pack as the GTM giving the GTM more battery life.
I have been looking at some of the solar battery banks also to power only my GTM. Was curious if you were able to determine whether a 15,000 mAh battery is able to keep it’s charge using solar while also powering just a GTM? I can’t find anywhere the spec for the current used by the GTM.
It depends on where you are and the availability of sunlight. For example, I have two Ring cameras hooked up to solar power only. Summer is no issue. Winter, both cameras eventually lose power and struggle to make it through the next day.
So far I have one node on a 20100mah battery pack that has made it 33 days on solar. But I have to be ready to swap battery packs with a fully charged one at that point. I have another one with much less sun (trees and buildings blocking over half the sunlight) that only makes it about 7-8 days on solar. That is summer time Indianapolis.
I think @MikeL has mentioned he can keep a unit powered with an 8000mah battery pack and solar in Urbana.
You’ll need to do some testing and see what works in your location and your sunlight availability.
