Eco-Worthy System - Need Help

jennyb_1977 · September 2021

Hi all,

We purchased a system for our cabin in WV (sorry we're a bit east). It came with:

195W Mono Solar Panel*6
60A PWM Solar Controller*1 (12/24v)
3500W 24V-110V Pure Sine Wave Inverter*1
100Ah 12V AGM Battery

We used this for a few weeks and then we were gifted a window A/C unit. We quickly realized we needed more power. We got 2 more of the batteries and upgraded the 60A PWM Charge Controller to 48V and the Inverter to 3500W 48V.

However, now it doesn't seem to recharge the batteries. The batteries are connected in a series. The panels are also connected in a series. I can not get Eco-Worthy to return any calls or messages.

We received no instructions on the charge controller so I don't know if we need to change a setting there, if we need more panels, if we need to connect the 4 batteries in parallel?

Does anyone have any ideas? For now the window unit has been stored until next July. Leaving us with a maximum of about 10kwh usage per day. We are now also contemplating getting another 24V inverter and connecting the batteries in parallel.

We receive 3.65 average peak sun hours per day.

I am truly at my wits end. Any help would be truly and deeply appreciated.

The pictures below are of 5 of the 6 panels and the original setup we had. Neither of us took pictures of the 4 battery setup

Image: https://us.v-cdn.net/6024911/uploads/editor/ad/aizqpc7wj7k2.jpeg

Photowhit · September 2021

First, STOP BUYING STUFF!

You certainly don't need as large an inverter unless you are running a very large air conditioner. Large inverters come with large idle energy use, you don't have a particularly large system. If the batteries were over a year old, I would likely have planned on replacing them with the new system batteries.

Air conditioners use a lot of energy. I ran a window unit on a small 24 volt system, a small window air conditioner will use around 450 watts when the compressor is engaged. 450 watts would draw about 450 x 115%=520 watts (inverter use a bit of energy when converting DC to AC) 520 watts divided by 24 volts = 22 amps or about 10% of the battery capacity. This will also use more of the battery bank capacity, because battery capacity is based on draining over 20 hours or 1/20th...

Once drained, your ability to recharge the battery bank with 6 - 195 watt panels will be challenging. I started with about 1000 watts of array and in summer our heat comes with sunshine so had 6-7 hours to recharge my battery bank. I suspect you have more sun than your annual average during the long days of summer. you can check here;

PVWatts Calculator (nrel.gov)

I ran my 220ah 24 volt flooded lead acid battery bank down to a bit below 50% of capacity every night, running and I wouldn't get more than just fully charged each day. I built a very well insulated 10x16 cabin to do this with 6" thick insulated walls, built in the shade. I added to my array until I reached about 1600 watts allowing me some runtime during the day once my batteries reach absorb stage of charging.

Here are the stages of charging.

The voltage you are seeing is the system voltage and not the battery voltage. If you are connected to charging or a load it will effect the system voltage.

During charging, there are basically 3 stages of charging, Bulk, Absorb, and Float.

BULK;

First thing when charging starts you will be in bulk, the voltage rises from what ever the system voltage was to a set point, around 14.5 volts. At that point the Charge controller stops the voltage from rising. Higher voltage can damage sealed batteries.

ABSORB;

Once the battery hits the preset point the charge controller keeps it at that point. Your batteries are roughly 80% full. Flooded batteries will start accepting less current at 80-85% full AGM/Sealed may go a little longer before accepting less current.

On many controllers you can set this point, Some will have different presets for Flooded, and sealed batteries, or flooded, AGM, and sealed batteries.

The charge controller has a couple ways to know when to switch to float, Most inexpensive Charge controller are just timed for 1.5-2 hours. Some will also see less current flowing through the charge controller and shut it down when minimal current is flowing through the controller. On more expensive charge controller. You can set battery capacity to give the Controller a better idea of when to stop. you can also set a longer Absorb time. Or set 'end amps' a amount of amps flowing through the charge controller to stop Absorb and switch to the final stage.

FLOAT;

Once the Controller has determined the battery is fully charged it reduces the voltage to a point where very little current is flowing to the battery. This will prevent the battery from over charging and heating up.

While in 'Float' the charge controller watch for voltage drop, which would indicate a load. If the voltage begins to drop the charge controller will allow as much current to flow from the panels/array to compensate and maintain the voltage. If the voltage can be maintained, the load will in essence be running directly off the array/solar. If the voltage drops below the preset float voltage, the controller may start a whole new cycle if it stays there for a period of time.

The system voltage drop you see at night when the sun goes down is the charge controller moving into a resting mode with no energy to contribute to the system.

The morning voltage may reflect a load present that is effecting the voltage level.

More in the morning...

Photowhit · September 2021

We will want to know the VMP of the panels, to be able to help you out.

A quick look, you say they are currently hooked up on series, One string? To an PWM charge controller? I suspect in a single string they would be too high for some inexpensive charge controllers. If they are 12 volt nominal panels (VMP of 17-21 volts) then even if they aren't too high a voltage for a 48 volt PWM charge controller, you are losing the use of 2 panels because PWM can only pass along the amps from the panels.

Photowhit · September 2021

So I'm still up, looked up the charge controller, inverter, and package deal. It's not the worse package deal I've seen, but the info on the inverter and charge controller are suspect. the charge controller specs say;

Image: https://us.v-cdn.net/6024911/uploads/editor/0j/eas3brvskfm5.jpg

So hopefully these are wrong since a 48 volt bank should be double the 24 volt specs, looks like someone just added them...
This might be a rebadged Y-Solar product, I will check there for a manual tomorrow.

If they can't provide an operating manual, I would personally consider returning them on principle.

I realized I could look up the panels, they show this info;

Image: https://us.v-cdn.net/6024911/uploads/editor/q7/8gkakwq379ry.jpg

Again, not listing the VMP is a red flag for me... Shows they are pretty clueless... Be we know Amps x volts = watts so 195watts/9.02amps=21.6 volts which they list as the VOC, so something is wrong(Voltage open circuit... my heart says "god just return these things...quality control must be pretty ugly there")

706jim · September 2021

I just can't see running A/C with those two tiny batteries.

mike95490 · September 2021

You do realize, that the PV panels in your picture are not connected to anything and that their connectors are open to the elements and possibly now damaged. Any shadow on the PV panels ( like from the wires ) will greatly reduce the power output

jennyb_1977 · October 2021

Thanks @Photowhit ! @706jim we were running the A/C off of 4 batteries. @mike95490 Thanks but that picture was taken during installation and they were all connected that day and have stayed connected.

Here is what we did and so far it's working! We ran the 4 batteries in series & parallel to keep the voltage at 24. We have a 3500W inverter that is regulated (hoping that is the correct term) for 24v. The numbers on the display are immediately after hooking everything.

Image: https://us.v-cdn.net/6024911/uploads/editor/4s/8rix0wf5czpb.jpeg

Image: https://us.v-cdn.net/6024911/uploads/editor/xw/dkadqwv1m2uj.jpeg

Image: https://us.v-cdn.net/6024911/uploads/editor/ym/8gx921kcgcea.jpeg

Photowhit · October 2021

jennyb_1977 said:
Here is what we did and so far it's working! We ran the 4 batteries in series & parallel to keep the voltage at 24. We have a 3500W inverter that is regulated (hoping that is the correct term) for 24v. The numbers on the display are immediately after hooking everything.

Please understand that with solar electric systems, "working" is a relative term....lol.

You can be damaging your battery bank, and up and and still be up and running for a couple years before you suffer issues that would cost you money.

It appears that you have paralleled the batteries by 'laddering them' just adding positive to the positive and negative to negative. This is commonly done, but the batteries, as a bank, won't share the load or charging equally. It would be much better to use the same size and legnth cables/wires and hook connect them using the positive from one string and negative from the other string.

how-configure-battery-bank - Web

There is information about how to wire here;

SmartGauge Electronics - Interconnecting multiple batteries to form one larger bank

Just to understand when I'm talking about the inverter being so large, I ran an 1800 watt inverter for a few years, running my window air conditioner, sometimes 2, as well as additional appliances (microwave, washing machine, Foreman grill, bread machine, just not all at once.) I also run a 900 watt water heater as an opportunity load. That's with a 4000 watt of solar panels (originally and a bit larger before I replaced it)

Image: https://us.v-cdn.net/6024911/uploads/editor/nd/ay8f4k977y6v.jpg

Something else which is likely to reduce your output is the short panel mounts, these are often used for mounting on an RV which has limited options, but they will create for hotter solar panels which will reduce their output. Usually a 5-6 inch relief is suggested to create a chimney effect circulating the air under the panels.

jennyb_1977 · October 2021

Thanks again @Photowhit! I will suggest this to my bf. The only issue with cord length is that we can't currently go two deep/side by side in our shed.

Photowhit · October 2021

jennyb_1977 said:

Thanks again @Photowhit! I will suggest this to my bf. The only issue with cord length is that we can't currently go two deep/side by side in our shed.

They don't need to be 2 deep, just have the same size wires so that the resistance is the same. They don't have to move, just change the wiring so that the 2 added aren't 'laddered' web site like should help explain that term. AND that the power connection is from the positive of one and the negative of the other set.

Eco-Worthy System - Need Help

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