diy solar

diy solar

Low Amps at MPPT

cgreen

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Oct 1, 2021
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Setup (I have attached the spec sheets / manuals for each of the following components in my system)...
1) EcoWorthy 48V 3500W All-In-One Inverter 80A MPPT
2) 48V 200ah LiFePO4 9.6kWh battery
3) Six Heliene 380W solar panels (41.2V max / 9.23amps) set up in 2s3p

Problem...
The MPPT charges the battery extremely slow! It doesn't matter what the SOC is of the battery. When I test the amps coming in from the PV array at the inverter, it shows 25amps (I have some shading), however, the MPPT never shows that many amps; it will show anywhere from 3amps to 12amps (at best). The voltage, however, reads the same as when I test the PV array. What might the problem be?

If I charge via my gasoline generator, it will charge the battery fairly quickly at 20amps; and if I charge via grid power, it charges at the max 40amps and the battery charges within a few hours. But from my PV array, it's just not charging quickly. I have selected the correct battery type in the inverter. Any thoughts or ideas? Thanks!
 

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Is the 3-12A that you see on the MPPT the PV input amps or is it the output amps to the battery?
 
Setup (I have attached the spec sheets / manuals for each of the following components in my system)...
1) EcoWorthy 48V 3500W All-In-One Inverter 80A MPPT
2) 48V 200ah LiFePO4 9.6kWh battery
3) Six Heliene 380W solar panels (41.2V max / 9.23amps) set up in 2s3p

Problem...
The MPPT charges the battery extremely slow! It doesn't matter what the SOC is of the battery. When I test the amps coming in from the PV array at the inverter, it shows 25amps (I have some shading), however, the MPPT never shows that many amps; it will show anywhere from 3amps to 12amps (at best). The voltage, however, reads the same as when I test the PV array. What might the problem be?

If I charge via my gasoline generator, it will charge the battery fairly quickly at 20amps; and if I charge via grid power, it charges at the max 40amps and the battery charges within a few hours. But from my PV array, it's just not charging quickly. I have selected the correct battery type in the inverter. Any thoughts or ideas? Thanks!
So that config should be putting out max about 27.69 amps * 82.40 volts =2281 watts. That is a bunch. What watts does it show in the best sun angle? When you say that you test the output out of the solar inverter, are you saying out of the solar controller? If you are checking the amp rating past the inverter, you are measuring the ac output load not the actual amps out of the solar panels. 3 to 12 amps would be 360 watts to 1440 watts of amp draw feeding your ac appliances. So the 25 amps would be correct by the sensor coming out of your panels. You may be confusing amps being supplied by your panels vs amps being drawn out of your inverter. So lets say that you are drawing 12 amps out of your inverter and you are only producing 1500 watts out of your panels then for sure the batteries will take a long time to recharge. What you need to check now is what watts your your panels are putting out or how many KW it produces in a day. That should help you figure out if the power that you are producing is in line with your usage + battery charging. Check this first and then turn the next page to look for more info.
 
So that config should be putting out max about 27.69 amps * 82.40 volts =2281 watts. That is a bunch. What watts does it show in the best sun angle? When you say that you test the output out of the solar inverter, are you saying out of the solar controller? If you are checking the amp rating past the inverter, you are measuring the ac output load not the actual amps out of the solar panels. 3 to 12 amps would be 360 watts to 1440 watts of amp draw feeding your ac appliances. So the 25 amps would be correct by the sensor coming out of your panels. You may be confusing amps being supplied by your panels vs amps being drawn out of your inverter. So lets say that you are drawing 12 amps out of your inverter and you are only producing 1500 watts out of your panels then for sure the batteries will take a long time to recharge. What you need to check now is what watts your your panels are putting out or how many KW it produces in a day. That should help you figure out if the power that you are producing is in line with your usage + battery charging. Check this first and then turn the next page to look for more info.
Thanks for the info and the additional questions! I'm testing the volts and amps from the wires coming from the PV combiner box into the MPPT; so, I'm getting the reading from the PV array, not from the all-in-one hybrid inverter. On the inverter's LCD panel, it reads...
PV input = ~80 volts
PV output = ranges from 3 to 12 amps (so, yes, I may be confusing this reading with amps supplied by the panels vs amps being drawn out of the inverter... does this measurement "PV output" mean the amps being drawn from the inverter?)

The solar panels never seem to be powering my loads; the inverter is always drawing power from the battery, all the meanwhile the PV array is charging the battery. Even if the battery is 100%, the inverter will pull from the battery to power the load, and charge the battery via the panels. Isn't that incorrect? My understanding is, once the battery is full, then the panels will power the load.

I don't use a lot daily kWh. Typically, I may use 6kWh on most days (some days less) and on extremely heavy days, I may use 10kWh. So my system set-up should be right to handle those loads, especially on a clear sunny day!
 
Is the 3-12A that you see on the MPPT the PV input amps or is it the output amps to the battery?
I'm not exactly sure. The inverter's LCD panel reads... "PV output" and will read anywhere from 3 to 12 amps throughout the day. So I have been assuming this means how many amps are going to the battery to charge it. I know the PV array is giving 25 amps when I test the voltage and amps at the wires coming from the PV combiner box before they enter the MPPT.
 
PV output = ranges from 3 to 12 amps (so, yes, I may be confusing this reading with amps supplied by the panels vs amps being drawn out of the inverter... does this measurement "PV output" mean the amps being drawn from the inverter?) Yes you are correct, that is what is being fed to the inverter or used by the batteries. The inverter will always draw amps from the battery not the panels even if the batteries are full. One of my setups 4 , 305 watt panels which produces appx 4.6 kw per day. If your system was working correctly then yes, at 2281 watts you should be getting double what i get. Have you double checked all your settings on your programing? I am not that familiar with one box units so i am guessing there is a lot of cutoff programing, low cut, boist, high cut off, etc.
 
PV output = ranges from 3 to 12 amps (so, yes, I may be confusing this reading with amps supplied by the panels vs amps being drawn out of the inverter... does this measurement "PV output" mean the amps being drawn from the inverter?) Yes you are correct, that is what is being fed to the inverter or used by the batteries. The inverter will always draw amps from the battery not the panels even if the batteries are full. One of my setups 4 , 305 watt panels which produces appx 4.6 kw per day. If your system was working correctly then yes, at 2281 watts you should be getting double what i get. Have you double checked all your settings on your programing? I am not that familiar with one box units so i am guessing there is a lot of cutoff programing, low cut, boist, high cut off, etc.
Hey, GLC! From my calculations over the course of today, my PV array produced around 8.9kW (between 9am and 3pm). So, I am guessing that means my panels are only producing approximately 1481 watts per hour? And as you said, if the amps being drawn out of my inverter are only 6-12Amps, and my panels are only producing ~1500 watts, then I suppose this explains why my battery just won't charge quickly enough. The past two days, I have only used 2kWh each day and yet my battery is only at 60% at 4p today, and that's having given it a boost this morning by charging it via grid power for an hour.

I feel like giving up on all of this. Is there anything you suggest I can do to remedy this problem? I want to cut my tie with the grid completely, but with not being able to keep my battery charged, and assuming my panels aren't able to produce what I need, it doesn't seem likely I can get completely away from the grid.
 
Hey, GLC! From my calculations over the course of today, my PV array produced around 8.9kW (between 9am and 3pm). So, I am guessing that means my panels are only producing approximately 1481 watts per hour? And as you said, if the amps being drawn out of my inverter are only 6-12Amps, and my panels are only producing ~1500 watts, then I suppose this explains why my battery just won't charge quickly enough. The past two days, I have only used 2kWh each day and yet my battery is only at 60% at 4p today, and that's having given it a boost this morning by charging it via grid power for an hour.

I feel like giving up on all of this. Is there anything you suggest I can do to remedy this problem? I want to cut my tie with the grid completely, but with not being able to keep my battery charged, and assuming my panels aren't able to produce what I need, it doesn't seem likely I can get completely away from the grid.
Looking back at your figures, if the inverter is pulling 12 amps which is 1440 watts and you are only producing 1481 watts per hour, then that is your problem. You may be using all of your solar charging power to your appliances and really nothing is going to recharge your batteries. You are going to either have to produce more energy or use less to actually charge your batteries. Do you actually know what you use or pull out of your inverter in a 24 hour period? Do you have something like this to track it?
What are your specs on your controller as far as amps-watts-volts that it will handle? Can the unit be over paneled to boost energy production?
 
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