I have a problem

[80740321]

I very recently connected my system and i'm happy to say that it works! I'm running with 3, 310 watt panels with MPPT Solar Charge Controller, 4000 watt inverter and deep cycle battery bank (4x 12V).

My issue is that the charge controller display tells me how much watts I'm bringing in and it never seems to go above 118 W, even on the brightest sunniest day. Why is this? It should be harnessing more, no?

 

[Bud Martin]

Make and model of the SCC? What are other loads connected to the SCC beside the batteries? If the batteries are full then the batteries will not pull power from the Panel/SCC. If you load connected the it will pull more power to keep batteries charged and to supply power to the load at the same time.

 

[80740321]

Make and model of the SCC? What are other loads connected to the SCC beside the batteries? If the batteries are full then the batteries will not pull power from the Panel/SCC. If you load connected the it will pull more power to keep batteries charged and to supply power to the load at the same time.

Armada ARC60-MPPT Solar Charge Controller connected to the batteries and inverter.

I had the batteries down to 40% the other day but was still only pulling 118W in from the panels.

 

[snoobler]

Are those panels in series? If so, are you sure you're not seeing a PV voltage of 118V?

 

[80740321]

Are those panels in series? If so, are you sure you're not seeing a PV voltage of 118V?

Series-Parralel set up.

Thanks for the links on your reply. Very handy. Just trying to learn as much as I can!

 

[snoobler]

How do you get a series/parallel setup out of 3 panels? It's either series, or it's parallel with panels.

 

[80740321]

How do you get a series/parallel setup out of 3 panels? It's either series, or it's parallel with panels.

Misread. Panels in series, batteries in both. I didn't wire it. Should I have done this myself?

 

[snoobler]

Misread. Panels in series, batteries in both. I didn't wire it. Should I have done this myself?

Gotcha.

So, the panels are in series. Given the panel size, they're likely 72 cell, and 118V is very close to the Vmp of a typical 72 cell panel operating at peak power. It's easy to misread the display of an item, and I just want to confirm that's not happening here.

Can you read both the battery voltage AND the charging current going to the battery?

Armada ARC60-MPPT Solar Charge Controller connected to the batteries and inverter.

I had the batteries down to 40% the other day but was still only pulling 118W in from the panels.

If these are lead-acid, this should be avoided; HOWEVER, if you are reporting a % based on the Armada display, this is notoriously inaccurate. Do not be duped into believing this value is accurate. It is voltage based, and that's not a reliable way to determine SoC.

Do you have a battery monitor that counts current in and out of the battery?

 

[80740321]

Gotcha.

So, the panels are in series. Given the panel size, they're likely 72 cell, and 118V is very close to the Vmp of a typical 72 cell panel operating at peak power. It's easy to misread the display of an item, and I just want to confirm that's not happening here.

Can you read both the battery voltage AND the charging current going to the battery?



If these are lead-acid, this should be avoided; HOWEVER, if you are reporting a % based on the Armada display, this is notoriously inaccurate. Do not be duped into believing this value is accurate. It is voltage based, and that's not a reliable way to determine SoC.

Do you have a battery monitor that counts current in and out of the battery?

I can read both battery voltage and charging current on my interface (not accessible to me right now as I'm not on site tonight)

The batteries are lead acid.

I did have someone test the batteries to count the currents in/out and everything seemed to be okay. Should I invest in regular monitoring of the batteries? I was planning to add more batteries to my bank shortly.

Thanks for your help.

 

[snoobler]

I can read both battery voltage and charging current on my interface (not accessible to me right now as I'm not on site tonight)

Good. Please let us know. Pictures won't hurt either.

The batteries are lead acid.

If you want them to last, avoid discharging them more than 50%.

I did have someone test the batteries to count the currents in/out and everything seemed to be okay.

Any idea what was done?

Should I invest in regular monitoring of the batteries? I was planning to add more batteries to my bank shortly.

If you want to know the state of charge of the battery, you MUST use a monitor.

Off-grid Solar Battery Monitors

Building a vehicle mounted solar power system? Let me help.

www.mobile-solarpower.com

 

[80740321]

Good. Please let us know. Pictures won't hurt either.



If you want them to last, avoid discharging them more than 50%.



Any idea what was done?



If you want to know the state of charge of the battery, you MUST use a monitor.

Off-grid Solar Battery Monitors

Building a vehicle mounted solar power system? Let me help.

www.mobile-solarpower.com

I'll report back tomorrow with some pictures. I can look back on my display to the past couple of weeks.

 

[80740321]

Here's my pictures. I took the information from the best day over the past 2 weeks.


Load is 0 due to inverter.

Thank you!

 

[snoobler]

Battery voltage has stayed within 12.8-14.5V in the last two weeks?

12.8V is very high for lead-acid indicating your system has likely been mostly fully charged for the duration.

Didn't make the connection in the first post, but 4000W inverter @ 12V is VERY high current... 4000/12 = 333A.

What size cable do you have:

1. between the inverter and battery?
2. battery and solar charge controller?

Have you confirmed that all connections/lugs/terminals between the SCC and the battery are good?

Have you applied loads at peak solar to assess if the array will produce more power under load?

 

[80740321]

yes, it remains steady at between 12.8V-14.5V.

Should I be changing my inverter size?

Cable sizes- 10AWG/ gauge for solar panels to charge controller, as per solar place's recommendation.
Inverter to battery- 4 AWG/gauge, as per solar place recommendation.
battery to solar charger- 4AWG/gauge as recommended by Charge Controller manual.

I've confirmed everything is connected properly. Batteries are good.

It doesn't seem to produce more when applying loads at peak solar. Whether it's cloudy outside or sunny it takes about the same amount of time to recharge the batteries when I get them down to 50-60%.

 

[snoobler]

yes, it remains steady at between 12.8V-14.5V.

Should I be changing my inverter size?

Cable sizes- 10AWG/ gauge for solar panels to charge controller, as per solar place's recommendation.
Inverter to battery- 4 AWG/gauge, as per solar place recommendation.
battery to solar charger- 4AWG/gauge as recommended by Charge Controller manual.

I've confirmed everything is connected properly. Batteries are good.

It doesn't seem to produce more when applying loads at peak solar. Whether it's cloudy outside or sunny it takes about the same amount of time to recharge the batteries when I get them down to 50-60%.

4awg from battery to inverter is woefully inadequate for the full inverter power. 4awg @ 90°C is only good for 95A.

95A * 12V = 1,140W

4awg from SCC to battery is fine.

When you say 50-60%, what device is reporting that value?

 

[80740321]

4awg from battery to inverter is woefully inadequate for the full inverter power. 4awg @ 90°C is only good for 95A.

95A * 12V = 1,140W

4awg from SCC to battery is fine.

When you say 50-60%, what device is reporting that value?

What size should I be moving to for my cable from battery to inverter?

50-60% from charge controller. Tested with battery tester today at 71% on CC and the battery tester said "good". I can't replace that until shops open up from pandemic restrictions so cannot provide accurate % from that.

I was going to swap the 12V batteries out for some 6V batteries. Is that a good or bad idea?

You've been a great help to me with this. I've been watching Will's Youtube videos, but I really have a lot to learn!

 

[snoobler]

What size should I be moving to for my cable from battery to inverter?

50-60% from charge controller. Tested with battery tester today at 71% on CC and the battery tester said "good". I can't replace that until shops open up from pandemic restrictions so cannot provide accurate % from that.

The % from the charge controller is essentially useless. It's purely based on voltage, and that's not a reliable way to tell SoC.

If the lowest your battery saw for 2 weeks was 12.8V, it's highly unlikely that your battery was ever below 90%.

You should get a battery monitor that actually counts the Ah in and out of the battery and reports SoC based on the amount used vs. the battery capacity.

I was going to swap the 12V batteries out for some 6V batteries. Is that a good or bad idea?

No idea. Until you get the SCC figured out, it's definitely not a good idea. As it stands, with the minimum voltage of 12.8V over 2 weeks means battery capacity isn't the concern.

If you're not using the system, I understand why it would never go below 12.8V, but if you're using it, it's almost certain you're getting more than 118V.

Please provide:

1. Link to data for your batteries.
2. SCC settings for Bulk/boost/absorption voltage
3. SCC settings for Float voltage
4. Picture that includes your SCC, SCC wiring to battery and battery attach.
5. Picture indicating a charge of approximately 118W.

 

[Hedges]

Have you powered any loads with the inverter? Is it possible the batteries are just staying full, and that's why power delivered from PV has been so low?
12.8V is typical rest voltage for some fully charged batteries. 14.5V is charging voltage.

 

[80740321]

Have you powered any loads with the inverter? Is it possible the batteries are just staying full, and that's why power delivered from PV has been so low?
12.8V is typical rest voltage for some fully charged batteries. 14.5V is charging voltage.

Yeah, I run my lights off it when I'm working, charge phones/laptops/batteries for tools. I run a bandsaw off it when I need to.

 

[Hedges]

So almost no load, except if you run the bandsaw.
Draw the batteries down a ways, like hook up a space heater and watch battery voltage. See if charge current/power ever increases.