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Not getting full power out of pannels

NomNomCameron

NomNomCameron

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I have 15 285w panels wired 3 in series per string. I'm using an Epever 100 amp charge controller and it shows I'm only getting ~2.3kw?

I have the controller connected to a bank of 4 122ah lead acid batteries wired in series/parallel for 24v.

All connected strings are showing ~115 volts connected to the combiner so they all appear to be working.

The panels are just laying flat on the ground on cinder blocks which I know is inefficient but I should be getting (on paper) ~4.2kw out of 15 panels. Even with a 20% loss I should still get at LEAST 3.4kw?

Am I missing something or is that much of a loss just to be expected?
 
If your batteries are fully (or even almost fully) charged, the Epever will back off on the charging current in order to not overcharge your batteries. To confirm this is the case, discharge your batteries down to 50% SOC then reconnect the solar. My guess is you'll see significantly more power from the panels then.
 
Even at ~24v on the battery bank I don't get more than about 2.3kw

Could the charging c rate of the lead acid batteries play a factor?

I have a feeling that the lead acid batteries are my bottleneck and that's what's preventing me from being able to absorb the full potential from the panels
 
From the wiki:
diysolarforum.com

My panels are under performing. Why?

[see [URL='https://diysolarforum.com/threads/diagnosing-problems-with-a-photovoltaic-system.811/']Forum Thread[/URL] this is taken from for more] You have a solar array on your roof, how do you know it's putting out all the power it can be? An...
diysolarforum.com diysolarforum.com
 
That is a good link. A diagnostic tool they don't mention is to put a load on the system to eliminate any bottleneck. It can be done in a number of ways. I have a hybrid inverter that is set to non export and I wanted to see how the panels would do under full load and run a MPPT plot so I switched the inverter to export load for a few hours. The infinite load of the grid gave me a good plot and I apologized to my utility for the transgression. :oops:
 
Yup, Not matter how many additional panels You get, with a 100 AMP Controller and 12 Volt Battery System, You'll max out at 2.5KW. AT times my panels deliver more power than my controller can convert into the batteries, but I did that on purpose to have more power during less sun intensive periods; as the way I'm currently setup, the solar power I use is pretty consistent throughout the day. The batteries are used more as a buffer through the day, and to deliver power at night.
 
NomNomCameron said:
I have 15 285w panels wired 3 in series per string. I'm using an Epever 100 amp charge controller and it shows I'm only getting ~2.3kw?
Click to expand...
I am assuming you have either the Epever Tracer 10415AN or 10420AN charge controller, both of which are rated for 2,500W Maximum PV Power, and to which you are connecting a 4,275W array. I am surprised it hasn't already burnt your house down.
NomNomCameron said:
I have the controller connected to a bank of 4 122ah lead acid batteries wired in series/parallel for 24v.
Click to expand...
A typical SLA lead-acid battery should not be regularly charged above C/10 Amps, you have two parallel banks so 244AH, so maximum charge current should not regularly exceed 24A. Pushing 100A per your SCC rating should have already caused your batteries to explode and, presumably, once you have your full 4,275W array properly connected, will cause them to form a micro-singularity consuming you, your house and the rest of the planet.


You have invested a lot of money in this project, please, at the very least, read your component datasheets.
 
p.s. I recognise that I may have been a little melodramatic above.
 
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