Hello,
I would like to reach out for some help with what i need to do to keep some Solar camera trailers running off of the grid. This is a brief snapshot of the setup of the system:
(2) Schott Poly 235 Solar panels wired in parallel
(1) Victron Energy MPPT 10/ 50 Smart solar charge controller
(1) Victron Energy Phoenix 12/500 inverter
The inverter and charge controller are wired to (2) Fullriver DC224-6 6 volt batteries wired in series.
I would welcome any thoughts or direction to help me get this system working/charging reliably. Thank you in advance for your advice.
Jason
Manuals can be found on the Victron website, all info you need should be in there. You have 470W of panels and a 500VA inverter, the system will not work if you use the full inverter capacity. Therefore, your power consumption needs to be quite low for this system to work in low light days.
https://www.victronenergy.com/inverters/phoenix-inverter-vedirect-250va-800va
https://www.victronenergy.com/solar-charge-controllers/smartsolar-100-30-100-50
PwFarnell,
Thank you for your feedback. Do you think this system would work better with a smaller inverter? Our issue is it does not seem like the batteries get a good charge so the system powers down 8 hours after the sun goes down.
Jason
The inverter has a minimum power consumption of 6W, so 0.5A which will be 144Wh or 12Ah without any power being supplied. The smaller inverters are slightly lower. Then they will be around 85% efficient for moderate loads. A smaller inverter may be a bit better but not much, your power requirement over a day is probably more than you can generate. At small scale 12V equipment is more efficient if you can get it.
Look at your power requirement, add 15% plus another 6W. Multiply by 24 to get the daily energy requirement. Then compare with a solar calculator for your location. You may need more panels.
The battery is small. You only have just over 1kwh of usable storage which about 83W over 12hrs. If you swap to a lithium 200 or 300ah you will double the usable capacity because you can on use 50% of the AGM capicity.
If the trailer will be outside in the cold, you’re better off with the Flooded Lead Acid batteries than LiFePO4, which should not be charged when they are below 32°F.
The solar panels, in an optimal setting, will replenish at most 313 Ah. 470 watts / 12 = 39.16 amps x 8 hours = 313 Ah. That’s a very optimistic charge and is unlikely to be achieved except during the summer with the panels oriented in just the right direction. My guess is that you wouldn’t budget for more than 200 Ah of charge.
The battery is 224 Ah, so in theory the panels couldn’t replenish the battery from a 0% state of charge using the 200 Ah number. However, these are flooded lead acid batteries which shouldn’t be discharged below 50% state of charge. Plus, there is a load while the sun is out so not all of the 200 Ah would go into the battery. And there’s the unknown number: We don’t know your loads.
Without knowing your loads, you probably need more battery storage and more PV. The inverter likely isn’t the problem.