Post by Jonathon on Feb 11, 2020 23:09:08 GMT
Hey all! I've finally figured out a mind-boggling issue that I've had with my solar setup. Disclaimer that this is my first solar rig, so this might be common knowledge to you experienced folk. So, on to the problem.
When I initially set up I made sure that all of the systems were working correctly. Individual panels all looked good, reporting nominal voltage & amps. On a bright sunny day, I was getting an average of about 300W from my 4x100W panels (wired two panels in series, then parallel joined the groups). On one particularly wonderful day, I managed to squeak out 408W! All of these wattages come from the Renogy BT mobile app on my Android device where it lists "Charge Power" in the Monitoring tab. I was stoked! My setup is working great!
Here's where things get weird. I would randomly check during the day, and see that my charge power was very low for the conditions. It would be perfectly sunny with no clouds and a light breeze blowing to keep the panels cool; just like the days I tested and gathered my averages of ~300W. But when I checked my mobile app, I would only be seeing a charge power of ~80W! Yikes! Where did my power go?! After doing more testing, I would notice that in the morning hours, I would be getting great charging power. Then around 11AM-noon, the charging power would taper off and settle around 80W. Super weird.
I spent days troubleshooting the various pieces. I thought maybe my wiring got stepped on and was partially shorting out under high load. Maybe a connection was loose. I'd disconnect everything, check it out, and reconnect everything. For a brief period of time (~60 seconds), the mobile app would report great wattage, close to the 300W I would expect. Then I'd check back a few minutes later and it would be back down to ~80W! Despite being in the same conditions as it was when I tested it 15 minutes ago!
I tried wiring everything in series. I tried wiring in parallel. I tried switching the order of the panels. Got the same effect from all configurations. I've been scratching my head for weeks.
But today, I have finally figured it out. When my battery is charged to 100%, the charge power in the mobile app drops to some lower number based off what I am currently drawing from the battery. So if my battery is charged to 100%, and I'm drawing ~40W through my AC inverter (checked with a Killawatt), the charge power will read ~80W coming in to the system. If I start drawing more current (~120W) from the inverter, the charge power in the mobile app correspondingly increases! Hah! I verified this several times by triggering some larger draws. Happens every time. So it's just a quirk of what the app reports when the battery is topped off. Being new to solar, I thought this was weird; I expected the app to report what my panels are bringing in regardless of the state of the battery.
Just putting this out there in-case someone else gets confused. I spent many hours trying to figure out why my incoming charge was so low at "random" times! Not sure if this is a common thing with all charge controllers, or if this is just something with this particular Renogy setup & mobile app. Hopefully this helps someone, or you at least enjoyed hearing about my suffering.
When I initially set up I made sure that all of the systems were working correctly. Individual panels all looked good, reporting nominal voltage & amps. On a bright sunny day, I was getting an average of about 300W from my 4x100W panels (wired two panels in series, then parallel joined the groups). On one particularly wonderful day, I managed to squeak out 408W! All of these wattages come from the Renogy BT mobile app on my Android device where it lists "Charge Power" in the Monitoring tab. I was stoked! My setup is working great!
Here's where things get weird. I would randomly check during the day, and see that my charge power was very low for the conditions. It would be perfectly sunny with no clouds and a light breeze blowing to keep the panels cool; just like the days I tested and gathered my averages of ~300W. But when I checked my mobile app, I would only be seeing a charge power of ~80W! Yikes! Where did my power go?! After doing more testing, I would notice that in the morning hours, I would be getting great charging power. Then around 11AM-noon, the charging power would taper off and settle around 80W. Super weird.
I spent days troubleshooting the various pieces. I thought maybe my wiring got stepped on and was partially shorting out under high load. Maybe a connection was loose. I'd disconnect everything, check it out, and reconnect everything. For a brief period of time (~60 seconds), the mobile app would report great wattage, close to the 300W I would expect. Then I'd check back a few minutes later and it would be back down to ~80W! Despite being in the same conditions as it was when I tested it 15 minutes ago!
I tried wiring everything in series. I tried wiring in parallel. I tried switching the order of the panels. Got the same effect from all configurations. I've been scratching my head for weeks.
But today, I have finally figured it out. When my battery is charged to 100%, the charge power in the mobile app drops to some lower number based off what I am currently drawing from the battery. So if my battery is charged to 100%, and I'm drawing ~40W through my AC inverter (checked with a Killawatt), the charge power will read ~80W coming in to the system. If I start drawing more current (~120W) from the inverter, the charge power in the mobile app correspondingly increases! Hah! I verified this several times by triggering some larger draws. Happens every time. So it's just a quirk of what the app reports when the battery is topped off. Being new to solar, I thought this was weird; I expected the app to report what my panels are bringing in regardless of the state of the battery.
Just putting this out there in-case someone else gets confused. I spent many hours trying to figure out why my incoming charge was so low at "random" times! Not sure if this is a common thing with all charge controllers, or if this is just something with this particular Renogy setup & mobile app. Hopefully this helps someone, or you at least enjoyed hearing about my suffering.
