This has been driving me bonkers, I've done so much reading but are no closer to a solution. So I thought I'd turn here and see if someone can help.
Background / Overview
The solar site is on a hill, with a very clear view of the sky, there is nothing obstructing it.
The constant load on the site is 7 amps @ 24v (168w). This can flucuate +/- 3w but is pretty constant 24/7/365. It drives some radio equipment that has a constant draw.
I'm in New Zealand.
Equipment
Batteries - 4x 271ah (that's their 20h rating, their 100hr rating is 335ah) Nomad E2 Ultra AGM batteries. These are wired 2 x series and 2 x parallel to give a total output voltage of 24v.
Charge Controller - Outback Flexmax 80. I just plugged in a Mate3 today.
PV Panels - 8x 250w TNSolar TN250P-60 solar panels. These are wired as two banks in parallel, each bank consisting of four panels in series.
Settings
Absorb voltage - 29v
Absorb time - 7h
End amps - 10 amps
Rebulk voltage - 27.6v
Float - 27.6v
No equalisation setup or ever been run.
MPPT Mode - Auto
MPPT Sweep Mode - Half
Max Sweep - 90%
UPICK Percentage - 77%
Restart Mode - 0
Can anyone see anything in that that might cause it to get such a low AH, like today it only drew in 83AH, it was a little bit cloudy this morning, but clear most of the day (very rarely a cloud would pass), the temperature was around 15-20c max. The panels are clean as, and no blown fuses. There has been the odd day it's pulled through a lot, every couple of weeks it may get upto 200ah or so, but that's rare.. some days 140-160ah. But often below 100ah.
I have three sites setup similar. The other two sites, that I have no issues with, have 4 batteries wired the same way as below, only 6 panels (3 in series to make 2 banks of parallel), but they only draw 2.5amps constantly. They never dip below 25.2v even in the middle of the night regardless of weather.
I've posted a comparison of the two sites charging from today. The number on the left is the voltage x100, so for example 2485 is 24.85 volts.
Good charging site
Good Site.jpg
Bad site
Bad Site.jpg
As you can see between 11:30am - 4:30pm the site didn't charge at all, as the voltage steadily dropped as it does overnight. Which is weird as that was pretty good charging conditions.
Background / Overview
The solar site is on a hill, with a very clear view of the sky, there is nothing obstructing it.
The constant load on the site is 7 amps @ 24v (168w). This can flucuate +/- 3w but is pretty constant 24/7/365. It drives some radio equipment that has a constant draw.
I'm in New Zealand.
Equipment
Batteries - 4x 271ah (that's their 20h rating, their 100hr rating is 335ah) Nomad E2 Ultra AGM batteries. These are wired 2 x series and 2 x parallel to give a total output voltage of 24v.
Charge Controller - Outback Flexmax 80. I just plugged in a Mate3 today.
PV Panels - 8x 250w TNSolar TN250P-60 solar panels. These are wired as two banks in parallel, each bank consisting of four panels in series.
Settings
Absorb voltage - 29v
Absorb time - 7h
End amps - 10 amps
Rebulk voltage - 27.6v
Float - 27.6v
No equalisation setup or ever been run.
MPPT Mode - Auto
MPPT Sweep Mode - Half
Max Sweep - 90%
UPICK Percentage - 77%
Restart Mode - 0
Can anyone see anything in that that might cause it to get such a low AH, like today it only drew in 83AH, it was a little bit cloudy this morning, but clear most of the day (very rarely a cloud would pass), the temperature was around 15-20c max. The panels are clean as, and no blown fuses. There has been the odd day it's pulled through a lot, every couple of weeks it may get upto 200ah or so, but that's rare.. some days 140-160ah. But often below 100ah.
I have three sites setup similar. The other two sites, that I have no issues with, have 4 batteries wired the same way as below, only 6 panels (3 in series to make 2 banks of parallel), but they only draw 2.5amps constantly. They never dip below 25.2v even in the middle of the night regardless of weather.
I've posted a comparison of the two sites charging from today. The number on the left is the voltage x100, so for example 2485 is 24.85 volts.
Good charging site
Good Site.jpg
Bad site
Bad Site.jpg
As you can see between 11:30am - 4:30pm the site didn't charge at all, as the voltage steadily dropped as it does overnight. Which is weird as that was pretty good charging conditions.
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