Archerite
New Member
Now I have already spend way more on my solar project than I planned for I just want to make the best of it. It's a tiny system that is not permanently installed yet. I have a victron MPPT, 2x 12V 7.2Ah SLA batteries (going to be in parallel), and a bunch of panels:
- 3 x 10 watt poly
- 2 x 10 watt mono
- 1 x 28 watt mono foldable
- 1 x 30 watt mono
- 1 x 120 watt mono foldable
These are not all connected at once offcourse, but they do all have around the same voltage between 18-22 volts when in full sun light. I have tried the 28w panel behind a window and that gives a max of 5-6 watts so not a great solution. The only place for the panels is a balcony that gets direct sunlight from 08:00-16:00 depending on the weather conditions offcourse. For the last few weeks of testing everything out I placed the panels outside in the morning on the outside couch/bench and when the sun went behind the roof I got them back inside again. That gets tedious really quickly
The reason for getting them back inside is that the connection are not weather proof yet. MC4 connectors and the right cable have arrived yesterday so that's going to be fixed. My plan is to place the 30 watt panel in the place where it will get direct sun for most of the day...till around 14:30 where it get's shadow. But there is still a tiny corner catching sun all the way till 17:00 on some days! So planning to put the two 10 watt mono panels there. I tried this while connected in parallel to the 30watt which was in full shadow using a single panel and got 8-9 watts from it during those last few hours.
There is a second balcony on the back of the house where the sun shines for maybe 2-3 hours more after the front is in full shadow. It's not something I have tested yet but it might be enough to keep at least the Rpi running during the night! It drains the battery (single 7.1Ah) to 12.3 in less than 12 hours! I am now fully charging both 7.2Ah batteries to create a 14.4Ah battery bank using a wall charger. The last one is already in float so I think it will happen today! ?
The main question I have is if it's smart to have so many panels connected in parallel with different wire lengths and half of them being in the shadow. The backside would require wires of at least 10-15 meters I think, so voltage drop might be an issue there too.
I have no schematic or drawing (yet)...sorry.
Thanks for any tips or advice.
- 3 x 10 watt poly
- 2 x 10 watt mono
- 1 x 28 watt mono foldable
- 1 x 30 watt mono
- 1 x 120 watt mono foldable
These are not all connected at once offcourse, but they do all have around the same voltage between 18-22 volts when in full sun light. I have tried the 28w panel behind a window and that gives a max of 5-6 watts so not a great solution. The only place for the panels is a balcony that gets direct sunlight from 08:00-16:00 depending on the weather conditions offcourse. For the last few weeks of testing everything out I placed the panels outside in the morning on the outside couch/bench and when the sun went behind the roof I got them back inside again. That gets tedious really quickly
The reason for getting them back inside is that the connection are not weather proof yet. MC4 connectors and the right cable have arrived yesterday so that's going to be fixed. My plan is to place the 30 watt panel in the place where it will get direct sun for most of the day...till around 14:30 where it get's shadow. But there is still a tiny corner catching sun all the way till 17:00 on some days! So planning to put the two 10 watt mono panels there. I tried this while connected in parallel to the 30watt which was in full shadow using a single panel and got 8-9 watts from it during those last few hours.
There is a second balcony on the back of the house where the sun shines for maybe 2-3 hours more after the front is in full shadow. It's not something I have tested yet but it might be enough to keep at least the Rpi running during the night! It drains the battery (single 7.1Ah) to 12.3 in less than 12 hours! I am now fully charging both 7.2Ah batteries to create a 14.4Ah battery bank using a wall charger. The last one is already in float so I think it will happen today! ?
The main question I have is if it's smart to have so many panels connected in parallel with different wire lengths and half of them being in the shadow. The backside would require wires of at least 10-15 meters I think, so voltage drop might be an issue there too.
I have no schematic or drawing (yet)...sorry.
Thanks for any tips or advice.
