Pairing up the Eco-worthy 20a MPPT controller

[JiminDenver]

Thanks to BFL confirming that the Eco-Worthy controller plays well when run with another controller, I felt pretty good about combining my two matched controllers. Each had one of the Bosch 245w mono panels aimed not perfect but good enough considering that they will be flat mounted. I used a fully charged 95 ah grp 27 so that I could move the voltage easier than the 8-D.

I used the inverter and a 1875w hair dryer as a load. I tried high but the voltage dropped so fast that the inverter shut off before I could check either the controllers or the meter on the battery. After shutting off the inverter the controllers put out a combined 28-30 amps until it hit float.

After it had been in float a bit I tried the low setting on the hair dryer. This time the batteries voltage only dropped to 12.3v and both controllers were putting out 13a average. I knew they were good for more so I disconnected one of the panels and the other controller shot up near 16a. This let the battery drop in voltage and when I plugged in the other panel, both systems ran close to 16a. They stayed that way until I shut off the hair dryer and inverter and let the battery come up.

I did find that I could use the high setting for short times if I started in low and let the controllers get ramped up. They were putting out 13a each until I hit high, then they jumped up above 16a each. The voltage did drop but slower this time. With the help of the solar, the hair dryer ran a minute before the inverters alarm went off.

I did get a chance to see the Mono panels with on and off clouds. Any significant clouding and the output dropped to 2.5a for each panel even if I was running a load. I didn't pull out the 230w poly but I've seen it do 3-4a in lower light. Just shutting down the inverter would save more amps than I'm losing, it's a real pig.

So I'm pretty happy with the combined systems. I'll probably see higher amps up at altitude but only if I'm running the microwave at high noon. With this in mind, I may go with the Rogue 30a instead of the Morningstar 45a for mounting and save the money. Clipping may not be a issue often and it would only be a few amps at peak hours.

Last thing is about the absorb cycle on the Eco-worthys. Even if I set the absorb at 15v, it didn't last. The controller would come out of bulk, switch to absorb and raise the voltage to the set point. As soon as it hit that the controllers dropped to float. I will say that 32a pushes a grp 27 around pretty easy. Next test it will be the 8-D, it doesn't push so easy.

[JiminDenver]

mena661 wrote:

BFL13 wrote:
So after all that we are back to where we were three years ago when I found out that 210w was perfect for us. Got to stop fixing things that ain't broke!

Always wondered why you switched from that setup.

Mena

BFL has fought the good PWM fight for years but we all knew the MPPT was going to win in the end. It is true he hid his dark side by posting that the MPPT advantage was a myth and that the expensive controllers were not worth it when PWM was so cheap.

Even when BFL finally caved in to his desires and bought his precious MPPT, he tried to hide it from us by claiming it was ONLY for comparative testing as he was going to prove once and for all......but look at him now. He is beaten. The MPPT has completely taken over and any remaining shred of PWM dignity has been ripped away. He will forever giddily collect his extra amps wondering if those poor people using PWM knew what was just beyond their grasp.

OR, like me, likes to buy new toys and play with them. 🙂

[mena661]

BFL13 wrote:
So after all that we are back to where we were three years ago when I found out that 210w was perfect for us. Got to stop fixing things that ain't broke!

Always wondered why you switched from that setup.

[JiminDenver]

West

The charging wires for each controller attaches to the lug on the battery.

BFL

Now that you got rid of that weak PWM stuff, you have room for another Eco-W set up. 🙂

[JiminDenver]

Almot wrote:

JiminDenver wrote:
the heaviest 12v load we have is a 12v, 200w, auto drip coffee maker. Running it along with the furnace, lights and fans might pull the system out of float.

Right now I am using a 3000w PSW inverter but plan on a smaller one for just the TV and dish. The draw at idle on the big inverter is crazy high.

Without self-aiming gizmos in sat system, 300W should suffice. Definitely will, if you switch to stove-top coffee. Or - tea. Lights you normally don't need - too much - at the same time with solar charging.

The tailgater itself is self aiming so I'll have to check in to the draw before I buy. One of the TV's is 12v so I may just run it that way and use a smaller PSW inverter on the receiver.

The little coffee pot makes a good load for testing, unfortunately it takes forever to make the worse coffee possible. Usually we use a Melita similar coffee pot on the stove.

[BFL13]

westend wrote:
With this talk of two controllers, it raised a question: Is there any problem with connecting two controller outputs to the same pair of wires and then leading that pair to the batteries?

That's just a parallel of the two controllers with extended battery posts. You don't save much wire if the controllers are both close to the batteries. You can save wire on the input side though. (PWM)

Last year I posted about my use of a Y on the input side using two controllers. I had 330w of array (a 130 and two 100s in parallel) to one long wire pair towards the battery bank, then the Y near the battery bank to the two controllers where each would supposedly take half the amps. Each controller was on the same battery bank. (could have been on separate banks I suppose for this exercise) This was to save having two long pairs from array to near the battery bank with a split array like the 130 on one long wire and the two 100s on the other long wire.

The Trimetric showed all the amps from the 330w was arriving at the battery bank, but I was not able to measure how many amps each controller did (no clamp on meter). Likely not quite equal since R of each leg not likely perfectly equal.

So that works ok.

BTW I am now just an MPPT guy (How low can you go? 😞 ) I am down to a JiminDenver 230w plus Eco-W set. Another camper here has my Sharp 130w panel and the RJ Special to run it. I kept the Solar30 in case I ever get another 12v array. So after all that we are back to where we were three years ago when I found out that 210w was perfect for us. Got to stop fixing things that ain't broke!

[westend]

With this talk of two controllers, it raised a question: Is there any problem with connecting two controller outputs to the same pair of wires and then leading that pair to the batteries?

[Almot]

JiminDenver wrote:
the heaviest 12v load we have is a 12v, 200w, auto drip coffee maker. Running it along with the furnace, lights and fans might pull the system out of float.

Right now I am using a 3000w PSW inverter but plan on a smaller one for just the TV and dish. The draw at idle on the big inverter is crazy high.

Without self-aiming gizmos in sat system, 300W should suffice. Definitely will, if you switch to stove-top coffee. Or - tea. Lights you normally don't need - too much - at the same time with solar charging.

[JiminDenver]

Roy

With what you have told me about your power use, roof space and limited sunlight, I can't see 18-20a doing it honestly. You are taking your three grp 24 batteries down to 50% or roughly 112 ah and get 5 hours of good light. Even without losses and the acceptance rate tapering down, you are looking at 100 ah at best.

It would require two controllers but if you could get the 240w panel up there for a total of 440w I think it was a much better chance. A pair of Tracer MPPT controllers would allow you to run the 120w in series and the 240w on it's own. At least you can set both controllers to do the same thing.

I'd say two Eco-w's (only because they are cheap) but the pair of 120's in series would have to high of a VOC and you would lose the MPPT advantage in parallel.

Another option would be to find two smaller panels to fit where the 240w will fit. Maybe a pair of 80w or 100w and then all could run parallel on a single PWM or all in series with a MPPT controller. I know MPPT wouldn't give you a great deal more but if any one is a candidate for needing that extra bit of power, it is you.

Outside if that you can add a portable which could really up the amps all day or mount less, run the generator in the morning and let the solar finish it off.
it's too bad the big panels are such a hassle as portables. A pair of them on the ground tracking the sun and a pair of Eco-w's would give you a lot more power to work with. I could pull 32a for 12 hours and with the shoulder hours the total could be over 500 ah if the controllers stayed at max all day. (life on the mountain top is good ;))

[pianotuna]

Hi RoyB,

If the solar is sized correctly, this is NOT going to happen. Remember it is a bell curve. The smaller the battery bank the higher the watt to amp hour ratio should be. For small banks I'd aim at 1.5 watts per amp-hour.

RoyB wrote:
I'm having a bad feeling that once I get behind the charge state curve it will be hard to keep up without having to run the generator some to start off with.

Roy Ken

[RoyB]

I certainly hope I get to see some high DC current readings coming from my planned SOLAR PANELS going on my OFF-ROAD POPUP roof. I am wanting to get around 18-20AMPS to at least re-charge a couple of batteries in my bank before I lose the high sun in one day before starting my nightly run off the batteries..

I'm having a bad feeling that once I get behind the charge state curve it will be hard to keep up without having to run the generator some to start off with.

Roy Ken

[JiminDenver]

pianotuna wrote:
Hi Jim,

16 amps at idle? wow that's a LOT. Or is that a typo?

Hi Don

That is with my HF clamp meter around both positive leads from the battery. That may be wrong because if I remember right, the controllers didn't bump up to cover a 16a load when I switched the inverter on. more like 6 or 7a. Might be worth rerunning the test to see what it takes.

[JiminDenver]

mena661 wrote:
Jim, do you have a picture of it?

This is the listing. click

[pianotuna]

Hi Jim,

16 amps at idle? wow that's a LOT. Or is that a typo?

[mena661]

Jim, do you have a picture of it?

[westend]

Jim,
I have a Xantrex 1000W and it is rated to draw .6 amps at idle. I suppose I should put a meter on it and check but I would bet it is close.