Eco-worthy 20a MPPT controller

[JiminDenver]

Last month I purchased the Eco-Worthy 20a MPPT controller from their website for $89 plus $24 shipping. Right now it says $102.50 and free shipping. You can see them on ebay with free shipping and if good can get one for as low as $80. That will be on a slow boat too as it took forever to get here.

Eco-worthy

u tube video I found on it

I set it up crudely this morning and wouldn't you guess, instantly had cloudy skies. Dark enough that there were no shadows and the controller was at best showing 2a. The panel is my Schott 230 watt, 36v panel rated up to 7.66a imp and 8.33a isc which I've confirmed before. It is just leaned against a fence and not tilted /rotated for best results

I started out using old batteries as a test, better to fry them than my trailers grp 27. They could be pulled down fast using a 350w inverter and a few lightbulbs, otherwise even in the shade the batteries voltage jumped and the controller went into float mode. In float and absorb modes it does PWM, only bulk mode does MPPT.

When the clouds cleared or as much as can be expected with the pollution, haze and smoke from the fires, I saw the amps jump to over 12a but only for a bit. They started dropping and went down to just over 5a in bulk mode. The controller is black , sitting in the direct sun and had gotten quite hot to the touch. It has a temp sensor in it so I am assuming it caused the cut in amps because even shading the box with my hand caused the amps to rise above 7 again. I shaded it and the amps went back up.
The best I saw was 13.1a in bulk mode. The controller has a PWM-MPPT comparison and at 13.1a it said the comparison was 8.67a in PWM. This is a calculation and too high for the rating. In absorb mode (PWM), in full sun it read in the 7a+ range which is close to the rated imp.
At that point the inverter was running 160w of bulbs and the batteries voltage was still climbing.

The next test will be to see if the set up will recharge the TTs grp 27 in a day after being brought down to 50%. If it can, I will be thrilled because even with furnace use we never see a 50% drop now and the Generator can be silent once again. Not bad for $200 invested.
If it can not, I'll have to decide if the controller is good enough and can be run in parallel like cruz does or send the controller back and run both of my panels off of a Rogue.

A few other tidbits.
as i mentioned, the temp sensor is in the case. I am going to see if I can't make it remote to the batteries somehow. That is a big advantage to the Rogue among other things but for a $250 savings I'll make sacrifices. I just need a charged battery for boondocking.

[DSchmidt_2000]

Did some testing today. (sorry for the data not being aligned- don't know how to post formatted text).

Setup:
45W 12V Solar Blvd panel with these specs
Maximum Power Voltage (Vmp): 18.0V
Maximum Power Current (Imp): 2.5A
Short Circuit Current (Isc): 2.73A

12V 35AH SLA battery which I depleted about 75% yesterday

Watt's-up meter in-line with the battery to measure current INTO the battery, battery voltage, and watts into battery.

DMM to measure the solar panel's voltage at the input of the MPPT controller.

I have Deans Connectors between the watts-up and the MPPT controller and between the solar panel and the MPPT controller so I can easily unplug things and make changes.

Testing: What I did was measure the current going into the battery if the MPPT controller was "in-the-loop", and then connected the solar panel directly to the battery. With the Deans connectors, I could do this switch around in seconds.

Here are the measurements in order they were taken (if no measurement listed - then I forgot to write it down)

With the MPPT "in-the-loop"
Solar V     Batt A     Batt V      Watts
16.76       3.08       12.51
17.00       3.05       12.51

Solar direct to battery
Solar V     Batt A     Batt V      Watts
            2.89       12.50V      35.5

With the MPPT "in-the-loop"
Solar V     Batt A     Batt V      Watts
17.05       3.02       12.51       37.4
16.94       3.07       12.52       37.1

Solar direct to battery
Solar V     Batt A     Batt V      Watts
            2.93       12.51       35.7

The battery voltage and watts were from the Watt's-up meter - it has uncertainty in its measurements hence the watts reported are not exactly that calculated just doing the math.

I'm a bit disappointed to not have a much greater charging amps (only ~ 0.1A greater) given the delta between the battery and the panel is about 4V. Thinking that I may just be so low in power that I'm not in a high efficiency zone for this MPPT controller.

Putting my ear to the MPPT controller, I hear a regular 'ticking' noise. Will at some point drag out my digital scope and take some measurements to see what is going on.

[JiminDenver]

The you tube video early in the thread pointed out the temp sensor in the case. I've seen the controller drop the amps from 12 to below 6 when the case heated up in direct sun and bring them back up once it was placed in the shade and cooled down. Too bad i didn't have a DVM on the battery to see what happened to the volts at the same time.

[HiTech]

Derate is all you need it to do. Very handy if it is functional.

Jim

[DSchmidt_2000]

HiTech wrote:
Wait it has a temp compensation thermistor?? Man if it is a PIC controller it would be fun to hack the code and customize it...tell us if you can read the code and update it!

On the Watts up did you blow the shunt like many of the rest of us lol? I desoldered mine by shorting it. If it is just the shunt, I was thinking of getting one to remote mount.

Jim

Looks like there is one, might only be used to derate the output when it gets hot. Not sure as there is no mention of it in the manual that shipped with it.

My 2nd Watts-up with a freebie from another RC flyer that broke the display. I replaced it but there is still no image as I think I need a 3.3V model which I just ordered.

[HiTech]

Wait it has a temp compensation thermistor?? Man if it is a PIC controller it would be fun to hack the code and customize it...tell us if you can read the code and update it!

On the Watts up did you blow the shunt like many of the rest of us lol? I desoldered mine by shorting it. If it is just the shunt, I was thinking of getting one to remote mount.

Jim

[JiminDenver]

Thank you for the review. I may not understand most of what you said but agree that I am happy with the performance.

I look forward to your additional post.

[DSchmidt_2000]

JiminDenver wrote:
A second member just received one so we should be getting another review here soon.

I'm the other guy that bought one of these from the Eco-Worthy website. $102.50/shipped, and it was shipped from a US address (I think it came from So. Cal). Bought it May 10th, I think it was in my hands on May 15th.

Opened it up and saw the large toroid in there for the buck topology. Power transistors and flyback Schottky are TO-220 cased and clamped to the sides of the case. The thermister is also clamped to the case to the upper right side.

Not 100% sure as I haven't poked too much at it, but I think the buck controller IS the microcontroller - a PIC 18F series chip. There are a pair of 25-turn trimmers on the board - not sure what they're used for but maybe to calibrate the current and voltage measurements. Not much else on the board semi-conductor wise.

There is a 5 pin header (or was it 6?) at the top of the PCB which looks like the same in-circuit serial programming header used for PIC controllers. I haven't tried to read out the contents of the chip to see if it is read protected.

As far as operation goes, my test setup right now is just a pair of 8AH 12V SLA batteries and a single 45W 12V panel. Again, this is just for playing - it's what I do.

I have a Watts-up meter right now in series with the battery to measure current INTO the battery. I have a second Watts-up that I need to repair and once I do will go in-line with the solar panel. For now I am measuring solar panel current with a DC clamp meter and measuring the voltage with a standalone DMM.

Around 9AM with the panel tilted to the sun, I was measuring ~ 2.5A into the battery and 2.05A from the solar panel. Measuring the voltage from the solar panel the controller was finding Vmp at ~ 17.4V (solar panel is marked Vmp at 18V).

Every 2 mins the controllers re-seeks MPPT as evidenced by the solar panel voltage shooting up to 21V, then dropping down to under 15V and quickly creeping back up.

As I do more testing I'll post more but likely not before I get my 2nd Watts-up meter repaired. Also will hookup a larger SLA battery (35AH) later but need to drain it a bit.

Lastly I do have a USB data logger (MCCDAQ 1208LS) that someday I'll get wired up to automatically track solar/battery voltage/current over time but I need to get some current measurement IC's on order first.

Happy with the 'performance' right now. As mentioned elsewhere, this will allow me to buy and play with those cheap 24V panels from Solarblvd.

[HiTech]

It does it is just nice to measure it both ways at the battery.

Jim

[JiminDenver]

Thank you PT, I knew it wasn't much with 12v panels.

Jim

I've never connected the panels directly to the battery. I have seen the panel do 9 amps on the meter and 15 amps thru the controller if that helps.

[HiTech]

Hey Jim have you or any other Eco-worthy owner compared amps at the battery on the MPPT controller vs amps with raw panels connected to the battery? It would be great info to have amps for both vs battery voltage at a few different states of charge of the battery.

Jim

[pianotuna]

Hi JimID,

Probably more like an 8% gain. That would have to be balanced against losses for series connections of the panels due to shade.

As an aside, in the first 48 hours of urban boondocking my solar replaced all the energy I used. I'm extremely happy with those results.

[JiminDenver]

The controller should be able to handle two of your 140w panels in series and that will give you the increased voltage for the MPPT function and give you a 10% gain from what I understand. Just make sure the combined VOC of the two panels are below the VOC limit of the controller. (42v)

[Mr_Grumpy]

Thanks for the quick reply. I agree, the benefits on a 140w panel wouldn't be huge, but it's still a benefit. Also, the 20amp controller would give me room to add an additional 140w panel. Though, as I said, I'm not having issues yet... I just hate not knowing. It's all about the numbers!

I'll watch for the other review.
Thanks again!

[JiminDenver]

Am I still happy with it...I'm thrilled. A second member just received one so we should be getting another review here soon.

It is nice having the display for set up and such. I don't know that you will see a big gain with a single 140w panel though. Others understand that better than I do.

[Mr_Grumpy]

Hey JiminDenver.

Any updates with this 20amp MPPT controller? I've got a single 140w panel with a 10a PWN Morning star controller. I'm thinking I'd like the benefits of a controller with an LCD panel (current battery voltage etc) and getting MPPT would be a bonus. Happy with it? Still going strong?

I'm running two 6v batteries and last season with our current solar setup I didn't have any issues. All of our lights are converted to LED. I consider ourselves minimal users at this point as once the kids are in bed (9:00ish), we aren't really in the trailer using power for lights and such. We don't have a TV, just the basics in our trailer.

Thanks!