MPPT Charge Controller for LifePO4 Batteries

[noelex 77]

Originally Posted by socaldmax

Very nice!

It's indicating 15.8v from the panels, what is the advertised Vmp?

The Vmp of my panels is 17.9v, but this is at STC with a cell temperature of 25c. I think the NOCT with an air temperature of 20c is about 16.2v, but I don't have the NOCT specs in front of me.

My guess is that the cell temp would have been about 45c, 20c higher than the STC. (The air temperature would have been above 20c, but my panels have good airflow)

This reduces the voltage by about 1.6v (.08x20) so the real Vmp of the panels should have been about 16.3v (17.9-1.6)

My wiring is quite thick but say 2% loss of voltage in the wire between the panel and the controller would reduce this to just under 16v. A little bit more voltage loss in the connections and circuit breakers and the theoretical Vmp at the controller is very close to the 15.8v that the controller has selected.

The controller is continually recalculating the Vmp, but this result is quite typical.

The theoretical calculation of Vmp and the practical value agree quite closely, as they should do.

[socaldmax]

Originally Posted by dennisail

Do you know if the controller manual is available online?

I believe this is it. It doesn't actually "recommend" 300w, it says max panel output 300w for 12v panels, 600w for 24v panels, max controller output 20A.

Manual for 20A MPPT - eco-worthy solar panel online shop

[dennisail]

Thanks. Looks like reasonable adjustability. No temp comp for LA though? Also it does not really explain what triggers the changes from - bulk - absorb - float.

However it has everything required for lithium as there is no temp comp and the voltages are all adjustable.

[Maine Sail]

Originally Posted by dennisail

Looks decent! So you can adjust max voltages, absorption times, disable temp comp etc? Might be suitable for a lithium bank.

Dennis,

Long story behind that controller.

It was designed and engineered by Aurinco. Aurinco then had it built by a Chinese manufacturer. For a few years all was good then one day they got an email from a customer wondering if the "look-a-like" controller on eBay was the same?

The Chinese had STOLEN Aurinco's design/product, used cheaper than specified components, changed the sticker on the front to yellow, and began selling it retail for more than Aurinco was paying for them. Aurinco was RIPPED OFF BY THE SLEAZY CHINESE..

Yes, that controller does have local temp compensation but you won't find ANYONE at EcoWorthy (not the real name of the manufacturer just a front) who can tell you how to disable it. Aurinco won't tell you either as they have severed ties. I used one for a while on my LFP bank but the controller was located in an area that never broke 70F on our boat. I only used it for a very short time while waiting for the new Rogue to hit the street.. I am now using the Rogue 3048.

I physically bought out the last of the Aurinco genuine stock of the Blixt controllers, the good ones built to spec, when I found out they were dropping them. They are pretty good other than the local temp sensing circuitry.

While not the fastest or best performing MPPT controllers the original Aurinco Blixt controllers worked okay, and were reasonably priced. The best feature was the ability to custom program voltages.

The Chinese stripped all the good components out, replaced them with low cost crap, and who knows what it is now.....?? This is how the Chinese sometimes operate, steal, cheapen the product and sell to those who don't know the "rest of the story"......

Oh they even stole the manual Aurinco wrote.... I suppose there is good reason why MidNite, Genasun, Rogue etc.are all building their controllers here in the US..........

EDIT: The funny story is that I tried to contact the manufacturer to find out if it could be ordered without the temp compensation feature and built to original spec (I never trusted they would but was curious).. They did not even know temp comp was in there and it took two months to get to someone that even had any sort of clue, but no answer (remember they did not design it just stole it).

Ever since those communications about once a month or so I get an email asking me how much I want to pay to import these. The last communication I had with them they had dropped their pants to about $55.00 each (IIRC) and that was shipped...... The components Aurinco specified for the original Blixt cost more than that alone...... Even at $55.00 each you could not pay me to deal with these sleaze bags.....

[socaldmax]

Originally Posted by noelex 77

It is a shame to throw away power because of the limit of the controller, but if you have excess its not really important.

The controller has to protect itself to limit the current and it may be doing this by selecting a higher input voltage than the true Vmp perhaps giving you the impression the Vmp is higher than it is in reality.

15v is a bit high for the bulk voltage of most batteries.

The maximum of 20A is usually governed by the current rating of the components used. 22A suggests the meter is over reading (most likely) or the protection circuitry is slightly miscalibrated. Try and keep the ventilation up with the controller operating at its peak for long periods of time.

Yes it is a shame, but this is a trailer I rent out to others for weekend use and the fridge is normally run off of propane, so the battery bank and solar panels are overkill and don't really get exercised fully. They usually run a TV and satellite receiver or some LED lights off of it.

You're right, it gets pretty warm after a while if it's putting out anything over 17 or 18A. I drilled holes in the bottom and top plate to allow more air convection inside and added stick-on heat sinks on both sides. That seemed to help some, but for the most part it doesn't get called upon for more than 10A unless I'm doing the high current draw test.

[socaldmax]

Originally Posted by Maine Sail

Dennis,

Long story behind that controller.

It was designed and engineered by Aurinco. Aurinco then had it built by a Chinese manufacturer. For a few years all was good then one day they got an email from a customer wondering if the "look-a-like" controller on eBay was the same?

The Chinese had STOLEN Aurinco's design/product, used cheaper than specified components, changed the sticker on the front to yellow, and began selling it retail for more than Aurinco was paying for them. Aurinco was RIPPED OFF BY THE SLEAZY CHINESE..

Yes, that controller does have local temp compensation but you won't find ANYONE at EcoWorthy (not the real name of the manufacturer just a front) who can tell you how to disable it. Aurinco won't tell you either as they have severed ties. I used one for a while on my LFP bank but the controller was located in an area that never broke 70F on our boat. I only used it for a very short time while waiting for the new Rogue to hit the street.. I am now using the Rogue 3048.

I physically bought out the last of the Aurinco genuine stock of the Blixt controllers, the good ones built to spec, when I found out they were dropping them. They are pretty good other than the local temp sensing circuitry.

While not the fastest or best performing MPPT controllers the original Aurinco Blixt controllers worked okay, and were reasonably priced. The best feature was the ability to custom program voltages.

The Chinese stripped all the good components out, replaced them with low cost crap, and who knows what it is now.....?? This is how the Chinese sometimes operate, steal, cheapen the product and sell to those who don't know the "rest of the story"......

Oh they even stole the manual Aurinco wrote.... I suppose there is good reason why MidNite, Genasun, Rogue etc.are all building their controllers here in the US..........

EDIT: The funny story is that I tried to contact the manufacturer to find out if it could be ordered without the temp compensation feature and built to original spec (I never trusted they would but was curious).. They did not even know temp comp was in there and it took two months to get to someone that even had any sort of clue, but no answer (remember they did not design it just stole it).

Ever since those communications about once a month or so I get an email asking me how much I want to pay to import these. The last communication I had with them they had dropped their pants to about $55.00 each (IIRC) and that was shipped...... The components Aurinco specified for the original Blixt cost more than that alone...... Even at $55.00 each you could not pay me to deal with these sleaze bags.....

Wow! I had no idea!

Well, as bad as it sounds, it fills a niche for people like me who just want something cheap that works. I'm not a patent attorney, I'm a consumer. My only complaint with hte unit is that the case gets rather warm at anything over 17 or 18 A output, Aurinco should have used a case with actual fins on it for better heat dissipation. I'm not too sure if I would install one on my future boat - if so, I'd have a couple of backup units in the locker in case of failure. But anything can fail - even the most expensive units, and when they do, dead is dead.

Let's say I install an ABC 75 amp controller that costs $599 with 4x250w (1,000 watts) of panels on both sides of the roof. I'm getting partial shading of one side or the other every day, depending on wind direction. Due to the partial shading, I'm really only getting 35-40A at peak sun. At anchor, I'm getting a total of 65A with no shading.

My cheap friend buys the DEF 20A controllers that costs $100 ea and spends a bit more on 4 panels - 300w panels for a total of 1200w. He installs 1 panel per controller, so the MPPT function only has to calculate for that one panel, and if one or more of them is partially shaded, the other panels are putting out full power at peak sun. End result, on any given day, he has 2 controllers putting out 20A ea, and 2 controllers putting out 10-12A ea. Net result is he's getting 60-64A under sail (20-29A/hr more than I am) and he spent the exact same amount for his system that I did, except he's getting the advantages of greater efficiency of a single controller per panel, like they do with some grid tie systems.

But it gets even better. We're both into spare parts, so I carry a spare ABC controller for another $600. He carries 3 spare controllers for $300. Assuming my first one fails in the middle of the pacific and my second one doesn't, I'm still OK, just out whatever it's going to cost me to ship the controller and have it repaired.

My buddy just swaps in another $100 controller and tosses the old one into his electronics refuse bag for shore disposal and goes on. In the unlikely event a 2nd one fails, he still has a replacement and one more spare. Plus he still has that other $300 in his pocket for a cool underwater camera, or to put towards buying an M802 HF radio with DSC.

I'm not advocating this particular brand of controller, perhaps there is a better American made reasonably priced controller, I don't know.

I have to be honest, I've bought a lot of stuff, and quite a bit of it was the expensive versions, thinking that price = quality. What I've found is that mfr. attitude about replacement is more important. I've heard the phrases, "I've never seen that happen before!" or "That's impossible!" from so many companies that sold me "the best" yet refused to stand behind their equipment, if I had a dollar for every time, I'd be buying a 70' catamaran right now.

A good or long warranty doesn't guarantee that it won't fail, it just means you have to ship it back for repair when it does. Interestingly, the cheap Ecoworthy controller is fully conformal coated, with gold plated contacts. Compared to my $225 Blue Sky Solar Boost 2000e which has neither.

[conachair]

This youtube play list might be of interest to some on here...

http://m.youtube.com/playlist?list=P...TSYeQIcicM9Ghl


Sent from my SGP312 using Tapatalk

[Maine Sail]

Originally Posted by socaldmax

Wow! I had no idea!

My only complaint with hte unit is that the case gets rather warm at anything over 17 or 18 A output, Aurinco should have used a case with actual fins on it for better heat dissipation.

The original ones built to Aurinco's specs, with the Aurinco specified components, do not suffer these problems that I have seen. The Chinese substituted cheaper components and this is the type of situation you wind up with, I suppose?

[socaldmax]

Originally Posted by Maine Sail

The original ones built to Aurinco's specs, with the Aurinco specified components, do not suffer these problems that I have seen. The Chinese substituted cheaper components and this is the type of situation you wind up with, I suppose?

The front panel of my Solar Boost 2000e also gets quite hot when it's putting out similar current. I just assumed that there was no way to convert that much power without generating a bit of heat or spending 3 times as much.

Or maybe I bought a knockoff 2000e and it's not supposed to get that hot either... looking at all possibilities here.


Again, you're pointing at cheaper components, and assuming lesser performance. In some instances you're correct, a better part is necessary and costs more. In some cases, the tighter specs are a little overkill and a looser spec'd part doesn't materially affect performance.

Do you have any test results indicating these things don't work as advertised, either lower output or lower efficiency? I don't have an Aurinco Blixt to compare it to, so I have no idea how well the original performed.

From what I've heard, even NASA gave the contract to the lowest bidder, and this is far from sending a man into space. I can understand your feelings toward the mfr and the product, and especially Aurinco's distancing themselves from the unit.

I didn't know any of the history before I bought one, but I still think I would have bought one just for giggles based on the youtube videos that I saw of one opened up. I've been involved in electronics R&D and production enough (Special Projects for SPAWAR) that I'm familiar with great/good/bad electrical design and assembly. This unit isn't great, but it is surprisingly good for $100. How many other $100 MPPT controllers are conformal coated and come with gold plated contacts? I haven't seen any, much less a 20A controller for $100.

Again, I'm not encouraging anyone to buy one. It is what it is - cheap; a $100 controller. So far, it's doing it's job. Now if it burns down my trailer, I'll report back, I just ask that you don't publicly laugh at my plight!

LOL

[dennisail]

Socaldmax, your friend has the right IDEA imo and he shares the same philosophy I do. I will eventually buy one reasonably priced MPPT controller for each panel. Rather than one extremely expensive controller which costs more than 4 cheaper ones. That way I will have all the benefits of redundancy and the ability of MPPT to actually work as designed, which is impossible when one MPPT controller (no matter how good) is connected to a bunch of panels with various states of shading.

Sucks about the Chinese rip off But hey for $55 I'm sold. We have only ourselves to blame for globalization and the downfall of manufacturing in 1st world countries. I would promise to buy only good quality products made in my own country if everyone else joined me (they would have to for it to work again), but since they never will I am not going to pay the outrageous rising prices for falling quality local goods just to make a point. We will all be worse off for this in the long run. (well actually I just paid $1100 for a plastic AU made kayak, when I could have got a similar Chinese one for half that, so maybe that is not always true)

[travellerw]

Ok so I'm kinda a noob, but have done a ton of reading (just read this whole thread).

I have a question that I can't seem to find an answer for.. How would one go about integrating wind into a system like this?

Based on the information I have been reading, it looks like adding a wind charge controller in parallel with an MPPT solar controller might cause the MPPT to go into float mode. Ideally, I would like to dump amps into the batteries with both solar and wind.

What am I missing?

[mrm]

Originally Posted by travellerw

Ok so I'm kinda a noob, but have done a ton of reading (just read this whole thread).

I have a question that I can't seem to find an answer for.. How would one go about integrating wind into a system like this?

Based on the information I have been reading, it looks like adding a wind charge controller in parallel with an MPPT solar controller might cause the MPPT to go into float mode. Ideally, I would like to dump amps into the batteries with both solar and wind.

What am I missing?

Once you realise, that the battery (charge state) itself is a factor which determines how much charge is accepted, things should become clearer for you. Empty battery will accept all charge you can throw at it. Almost full battery does not need (won't accept) as much charge current, so one or more charge controllers going into 'float' (or shutting down) does not matter. The remaining one(s) will finish the job. Besides, with LiFePO4 we are talking about final few % of capacity in the upper knee region, which is best left alone for longevity. Below that, they will accept all you can realistically provide. This phenomena you wonder about is much more pronounced with Lead tech..

[travellerw]

Originally Posted by mrm

Once you realise, that the battery (charge state) itself is a factor which determines how much charge is accepted, things should become clearer for you. Empty battery will accept all charge you can throw at it. Almost full battery does not need (won't accept) as much charge current, so one or more charge controllers going into 'float' (or shutting down) does not matter. The remaining one(s) will finish the job. Besides, with LiFePO4 we are talking about final few % of capacity in the upper knee region, which is best left alone for longevity. Below that, they will accept all you can realistically provide. This phenomena you wonder about is much more pronounced with Lead tech..

Hhmm I'm still missing something.. I totally "get" that a battery will accept what you can throw at it.. What I'm talking about is an MPPT controller going into float mode because it detects a voltage rise from the wind charger (even when the battery is far from full).

Maybe I'm confused, but I'm under the impression that the charge controller from the wind generator will be putting 14V into the batteries when the wind is blowing. Wouldn't the MPPT charger detect this and say "oh the batteries must be full"? and go to float mode.

[s/v Jedi]

Originally Posted by travellerw

Hhmm I'm still missing something.. I totally "get" that a battery will accept what you can throw at it.. What I'm talking about is an MPPT controller going into float mode because it detects a voltage rise from the wind charger (even when the battery is far from full).

Maybe I'm confused, but I'm under the impression that the charge controller from the wind generator will be putting 14V into the batteries when the wind is blowing. Wouldn't the MPPT charger detect this and say "oh the batteries must be full"? and go to float mode.

No, there is no "putting 14V into batteries". A battery that is not full does not allow the voltage to go up there. What you put into batteries is energy expressed in Ah or kWh.

[travellerw]

Originally Posted by s/v Jedi

No, there is no "putting 14V into batteries". A battery that is not full does not allow the voltage to go up there. What you put into batteries is energy expressed in Ah or kWh.

Thank you.. That is exactly what I was missing (funny I knew that)..

Cool that simplifies it..