Affordable MPPT Charge Controller

[whiskthecat]

I have watched the ECO-Worthy teardown numerous times

Link to the teardown please? Don't hold out on us.

it is firmware upgradable in the field.

How do you go about doing this? Is there a USB port?

The screw terminals on the EPSolar controller are much beefier

Do you think threaded posts with a nut (like on most batteries) would be better?

The heat disipation design on the EPSolar controller is WAY better (potentially longer life)

I still say that if proper high quality low resistance components are used the heatsinking should have to be very minimal or non existent even, otherwise you are just wasting power. If this practice was used the ECO-worthy looks to have ample heatsinking to dissipate ~5ish watts. The controller itself is claiming above 98% efficiency, at 20A 12V thats 240W, 4.8W of waste. Of course I haven't seen a teardown so it's very possible that they aren't using low resistance components.

A remote panel allows you to check setting without conforming yourself to some wierd location in the boat.

Seems like a good thing to make wireless.

Can support LifePo4 batteries.

What all does that entail? Can it balance 3 or 4 series cells making up a 12v bank?

Socaldmax, is there anything you don't like about that controller? I notice it only accepts 42v in comparison to the others 150v. Looks like they also came to the conclusion that supporting higher voltage panels was not worth it and somewhat detrimental to price/performance.

[travellerw]

The teardown video of the eco-worthy is above..

The firmware in the EPSOLAR are is upgradable via the same port the monitor plugs into. It's rs485 I believe.

It would be pretty trivial to use 433mhz boards to make those panels wireless. Interfacing to a serial device is super easy. Fact is, I don't like wireless devices on a boat so mine will be hard wired..

I will email the company today to see if the have a later firmware, although I don't have a test rig to verify it operating correctly.

I have been in contact with the Australian gentlemen in the video, his controller has performed excellent so far.

Sent from my Nexus 4 using Cruisers Sailing Forum mobile app

[whiskthecat]

Oh, I thought maybe you had something more extensive than the video already linked. You can only see so much from that. I can't see any capacitors. It looks as if they are only using small value smd ceramics. That's kind of crazy especially for a single phase. I'd like to see someone hook a scope to the output of that thing while its under full load. The voltage and current ripple might be pretty intense.

I was thinking of using 2.4 ghz. It's high enough to not interfere with anything else boat related. If you are anywhere near a marina or coast you'll be being flooded with 2.4ghz anyways from all sorts of devices (microwave ovens, wi-fi routers, wireless phones). I doubt a sub-100milliwatt nanosecond burst of a couple kilobytes every few seconds is going to disturb any other equipment, if it does it's practically that equipment's fault for being so susceptible to the most minor of disturbances in the first place.

The other end of this rs485 cable plugs into your pc through USB?

I personally don't like the idea of having to rely on a company to provide firmware updates for a device they've already sold and been paid for. A commercial controller shouldn't even ship with a problem such as the one in that video. It should work 100% with the firmware it comes with and the update ability just used to add additional features if needed. As I said before I doubt it's a major malfunction but it certainly looks to be reducing the output for a non trivial amount of time while it goes about doing the weird things it's doing.

[travellerw]

As usually happens on CF people make a mountain out of a molehill. The Aussie fella says that it is not an issue once he put it in use.

In any case, I have provided my opinion and I will leave others to form their own. I'm confident enough in that hardware that I bought 3 of them.

Sent from my Nexus 4 using Cruisers Sailing Forum mobile app

[whiskthecat]

Indeed, a cloud is not a towel, lol. Those were extreme conditions in the video for sure.

[Maine Sail]

Originally Posted by socaldmax

I watched the youtube test of that controller, and frankly, I was very disappointed.

A good MPPT controller should be able to establish MPP within a few seconds - not 4.5 minutes, and it shouldn't get confused at 3 minutes and reboot itself. When he did the towel test (changed the panel output) it took forever for it to track, meaning that as clouds pass overhead, this thing is nearly incapable of maintaining MPP.

There's another 20A Chinese controller that I think is better. I've installed several of them, and I'm very impressed. It has the menu and display built in, and shows PV voltage and watts, in addition to battery voltage and amps. It establishes MPP within a couple of seconds and sweeps every few minutes, very responsive to input power changes. It uses a nice sized toroid and conformal coated PCB, in addition to gold plated contacts.

It sells direct from Eco-Worthy.com for $102 delivered. I have one with 410w of panels installed on it (max rated PV power is 300w for 12v battery, or 600w for 24v battery) but it regulates itself at 22 amps and after a yr of this ,just won't burn up. Another thing I like about it is the charging voltage can be adjusted in .1v increments all the way up to 15.5v if desired.

Here's a youtube video of a guy taking it apart, reviewing it's construction and testing it out on a bench.

Another review:

That is an interesting controller in that it was designed by a US company and then the Chinese company, which was contracted to build it, drastically cheapened it and then began selling it on eBay for less than they were selling the one to the company that designed it and the one they were contracted to build it for. They even went so far is to steal the US written manual. Rather than tie it up in lenghty law suits in China, which they'd never win, they threw in the towel and gave up.. Lots of US R&D dollars down the drain thanks to a sleazy Chinese company..........

I bought out the last of the stock on the "good versions" of that controller and then took apart the stolen Chinese look-a-like version and the components were all changed and cheapened. The original controller also had a better hill-climb algorithm and was a faster controller at tracking. There is no length to which some sleazy Chinese companies won't go.......

[socaldmax]

Originally Posted by travellerw

Yup the software has some bugs, but I fully expect the manufacturer to release a firmware update that will solve most of those problems. Actually I'm running a beta firware that was supplied, I just haven't had time to test it out. That is one of the features of this controller, it is firmware upgradable in the field.

That's an expectation of yours, not a fact. I really can't believe they released it to the public in that level of messed up. Yes, they might upgrade the firmware, but until then, it's really not usable.

I have watched the ECO-Worthy teardown numerous times and I can assure you, the build and construction of that controller is no where near equal to this one. Since I know people will as why, here are a few examples.
- The screw terminals on the EPSolar controller are much beefier they aren't a structural component, they carry current. Since those terminals are not gold plated, how long will it take for corrosion to drastically increase the resistance of the exposed wire connections? Not very long.
- The heat disipation design on the EPSolar controller is WAY better (potentially longer life) Yes, it has a larger heatsink, but the Eco-worthy I'm currently over driving has been operating at up to 110% for a year now, with no ill effects. You're guessing that this is a flaw. From my actual testing, it's a non-issue.
- EPSolar is using name brand made in USA or Made in Japan components I'm not a fan of large leaded components. The EW controller uses an array of surface mount caps, which is the preferred method for greater longevity. Surface mount components are preferred whenever possible. The're also completely conformal coated, It did not look like the EPS PCB had conformal coating. That is a potential source of corrosion, especially when excess flux gets reactivated by moisture in the air and literally eats the leads off of those 2 large unsupported caps. I've seen it happen a lot, even with much smaller, lighter components. Not a problem with surface mount devices.
- A remote panel allows you to check setting without conforming yourself to some wierd location in the boat. What it does is encourage people to install it in some small closet or cubby with no ventilation for that great heatsink, causing it to overheat. I have mine installed on the wall, where it can be seen and it gets plenty of air.
- Has a temperature probe (although a crappy one) It's not effective, so it makes no difference. How do you mount it to the battery?
- Software settable. That is pretty cool, but since you can get the remote panel for an additional $35, it's kind of a gimmick. Are there settings the computer can access that the remote display cannot?
- Can support LifePo4 batteries. So can the EW, just set the charging voltages to whatever you want.

Now don't get me wrong.. The ECO-Worthy controller is not crap, but I beleive this one is a better build. Software needs some work, but it will get there.

In summary, I think conformal coating and gold or silver plated connectors are a must in a salt water environment. The heat sink is better, but it's really not an issue with the EW controller. It has an internal temp probe and it will cut back on power if necessary. So far, it's never had to do it even at 110% (22 amps.)

I like the price point, and the software upgradeability (although none of the major players have needed to tweak their algorithms that I know of) but until it actually ships with a working MPPT firmware, I wouldn't buy one.

After (when?) the firmware is fixed, I can see the 40 amp model being a real bargain, if only the contacts were gold plated. The current version (based on the pics) look like they'd corrode easily. That can really put a big dent in your solar harvest.

[SV THIRD DAY]

Originally Posted by Maine Sail

That is an interesting controller in that it was designed by a US company and then the Chinese company, which was contracted to build it, drastically cheapened it and then began selling it on eBay for less than they were selling the one to the company that designed it and the one they were contracted to build it for. They even went so far is to steal the US written manual. Rather than tie it up in lenghty law suits in China, which they'd never win, they threw in the towel and gave up.. Lots of US R&D dollars down the drain thanks to a sleazy Chinese company..........

I bought out the last of the stock on the "good versions" of that controller and then took apart the stolen Chinese look-a-like version and the components were all changed and cheapened. The original controller also had a better hill-climb algorithm and was a faster controller at tracking. There is no length to which some sleazy Chinese companies won't go.......

Bingo...that's standard operating procedure in China.
See the demand for the product you are making for a US company and then steal and cheapen it. Meanwhile knowing that the US company can't afford the fight and that US consumers for the most part don't give a rat's ass about it if they can save $20. It just is what is as bad as it is.

[whiskthecat]

The problem with those SMD capacitors is that it's difficult to get enough of them on to the board to have a respectable capacitance. I count about 35-40 on there which puts you under 1000uF for the whole unit. Seems woefully inadequate. For comparison the black electrolytic in the other unit looks to be a 3500uF part. Of course it is the type of thing your average user will never notice so why bother to do it properly when you can just cut the costs.

The less capacitance you have the more ripple voltage and ripple current you have. What this mean is that your battery bank is having to take the abuse the capacitors were meant to absorb. It causes internal heating of the battery. Probably not enough to be noticeable from the outside but enough to decrease the overall lifespan of your expensive battery bank for no reason other than they didn't feel like spending the extra $5 on an adequate amount of quality capacitors. It doesn't take much internal temperature rise to start quickly eating in to the lifespan of your batteries.

Here is a graph showing the effect of Ripple current on batteries.


If I were to use a few of those units in a setup I would at least take the precaution to install an additional external capacitor such as one of the large ones they sell for car audio in order to preserve the life of my batteries.

[socaldmax]

Originally Posted by whiskthecat

Socaldmax, is there anything you don't like about that controller? I notice it only accepts 42v in comparison to the others 150v. Looks like they also came to the conclusion that supporting higher voltage panels was not worth it and somewhat detrimental to price/performance.

I don't really think the 42v max. input voltage is that big of a deal, since it's only a 20 amp controller. One could connect it to a 300 watt or 320 watt panel and it's perfectly matched. If you can't find a 300 watt panel under 42v, then 2 160 watt panels in parallel will work.

If it were a more powerful unit (30 or 40 amps) then I feel it would be a lot better with 150v input for series connections, but it's just a cheap 20 amp controller for $100 delivered.

A nice feature is that it will support 600w of panels in 24v mode. So for those who are running 24v systems onboard, 600w of panels is nothing to sneeze at.

I do want to amend my comments on the EPS controller, it does look like it's conformal coated, I just had to zoom in to see it.

[socaldmax]

Originally Posted by whiskthecat

The problem with those SMD capacitors is that it's difficult to get enough of them on to the board to have a respectable capacitance. I count about 35-40 on there which puts you under 1000uF for the whole unit. Seems woefully inadequate. For comparison the black electrolytic in the other unit looks to be a 3500uF part. Of course it is the type of thing your average user will never notice so why bother to do it properly when you can just cut the costs.

The less capacitance you have the more ripple voltage and ripple current you have. What this mean is that your battery bank is having to take the abuse the capacitors were meant to absorb. It causes internal heating of the battery. Probably not enough to be noticeable from the outside but enough to decrease the overall lifespan of your expensive battery bank for no reason other than they didn't feel like spending the extra $5 on an adequate amount of quality capacitors. It doesn't take much internal temperature rise to start quickly eating in to the lifespan of your batteries.

Here is a graph showing the effect of Ripple current on batteries.


If I were to use a few of those units in a setup I would at least take the precaution to install an additional external capacitor such as one of the large ones they sell for car audio in order to preserve the life of my batteries.

According to that chart, it takes 8 amps of AC to increase the battery temp by 1*F. I seriously doubt there is even that amount of AC current, but even so...

1*F is nothing compared to ambient temp. swings. Where I live, night time temps can drop to 38* and swing back up to 78* 8 hrs later. I have no control over that, and one extra degree...

that's literally a drop in the bucket.

[socaldmax]

Originally Posted by SV THIRD DAY

Bingo...that's standard operating procedure in China.
See the demand for the product you are making for a US company and then steal and cheapen it. Meanwhile knowing that the US company can't afford the fight and that US consumers for the most part don't give a rat's ass about it if they can save $20. It just is what is as bad as it is.

A friend of mine is VP of Worldwide Projects or something like that, for Broadcom. His job is to travel all over Asia and make sure that all production goes to his company and they don't pirate any of their designs. The problem is, they pay him $300K/yr to do it. Not exactly cheap. On the plus side, they've recently won a couple of huge lawsuits for IP copyright infringement against their main rival, Qualcomm.

The other option is to keep mfg. here in the US. The US doesn't have a monopoly on greed, they're stealing US designs for the same reason that US companies move their production overseas - more money.

Another option would be to open a plant in Mexico, if the Hecho en Mexico sticker doesn't scare people off.

[whiskthecat]

Yes, you can't control your environment. But, that doesn't mean you want to have your batteries be constantly raised over ambient when you could have avoided it. That 1 degree over ambient is taking away 5% of your batteries lifespan regardless of what environment you are living in (and it's temp swings) because it is keeping the battery 1 degree over what it would have been. You can brush it off as trivial but batteries are expensive and capacitors are cheap. There is no reason for it.

[socaldmax]

Originally Posted by whiskthecat

Yes, you can't control your environment. But, that doesn't mean you want to have your batteries be constantly raised over ambient when you could have avoided it. That 1 degree over ambient is taking away 5% of your batteries lifespan regardless of what environment you are living in (and it's temp swings) because it is keeping the battery 1 degree over what it would have been. You can brush it off as trivial but batteries are expensive and capacitors are cheap. There is no reason for it.

I'm picturing everyone who lives in Phoenix, AZ in 120* summers.

What do they do, buy a new car battery every 2 months?

[whiskthecat]

Like I said, their batteries will have a shorter life than in a cold climate, nothing can be done about that. But that doesn't justify making it an even shorter life by sapping 5% more when you don't have to. Why make it a 121 degree summer? Was 120 not bad enough? It's a 5% reduction of what you are already working with in your environment. You can't look at it as if you are already so screwed that you might as well just keep increasing the damage. We are talking about less than 5$ of capacitors.