anyone want to promote cheap MPPT units?

System
System Posts: 2,511 admin
in Off Grid Solar & Battery Systems #1
I live on a sailboat and most of my power is solar (have a wind generator too) I noticed that MPPT units are ridiculously expensive for small systems, and the cheap on (BZ mppt 250) is crappy. It is much cheaper to buy more solar panels, but unfortunately the space for this is not always available. I think all solar panels should have MPPT support, and I want to work toward this goal, but I need a little help!

I have designed with success a prototype MPPT:
http://digitalsurveyinstruments.com/beagleperiphials/openppt/doc/index.htm

It has some limitations which will be revised in a future version, but it does work, and it is cheap. The main problem for me is distributing the units when I am between continents, but dealing with parts distributors and assemblers is a real time drain.

Here are some features I have in mind for the most basic model:

1. 60 volts 50 amps limits. It is not hard to increase this, but the parts to handle this are cheapest, and should prove useful for a wide range of small solar systems. It should be completely safe for 12v and 24v systems.
2. Programmable over usb/serial interface for any battery type (AGM gel/cell, flooded, LiPO4 etc etc...) Using a simple program which runs on any operating system. You can for example, set the battery type.. or fine tune with float voltage, enable/disable MPPT, view the efficiency and MPPT gains, use various algorithms, and tweak the operation in more ways than most people would normally want to (like change operating frequency).
3. Coulomb counter, this can basically can tell you the actual capacity of the battery, and determine the battery health.
4. All software and hardware design Open Source so the end user has complete control and understanding of the workings.
5. temperature sensor for correct temperature compensation.
6. Waterproof design

The above should be possible with the fewest number of components... A parts cost of $30 or less is easily possible. Factor in it costs another $30 to get the boards assembled at a fabrication house, and sell the board for retail of $120 This is for the initial 100 units, after that I would expect the costs to be half this for quantities of 1000 or more. I am being realistic not over optimistic.

Advanced features (not hard to add but we skip these early on to save time)

1, LCD display (so information can be displayed rather than requiring a computer connected over usb)
2. Capable of handling a load, and disconnecting in over/under voltage to protect electronics. Also can measure watt usage on load, can tell you power consumption, in instantanious, hourly, daily, weekly usage etc... Could plot power usage and trends, and even allow you to compare how well your batteries age compared to other users via internet database.
3. Advanced features, like fusing multiple battery banks of different types... the converter can shuck power from one bank to the other to increase overall efficiency, and reduce cost for large capacity systems...
4. Electric/servo motor control for rotating panels and providing solar tracking.
5. Your ideas? What else would be good to add? If you could care less about any of the rest of this, at least tell me what would be cool in a controller!


I would like to find some other people who are interested in this. The idea is to make MPPT more available to more people, and produce a controller which will be used under a wide range of setups. I made digital magnetometers with success, so I am confident I can make this become reality:

www.digitalsurveyinstruments.com

I have decided I don't want to deal with every aspect because it takes too much time. I want to promote more efficient solar systems to the world, and I need some help, and I cannot ship orders in a timely manner because I live in the middle of the ocean (sometimes).
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Comments

  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #2
    Re: anyone want to promote cheap MPPT units?

    i'm not to sure what it is you are looking for here. are you looking for somebody to beta test? or distribute? buy? what?
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  • halfcrazy
    halfcrazy Solar Expert Posts: 720 ✭✭✭
    #3
    Re: anyone want to promote cheap MPPT units?

    120 bucks what about UL Listing can you do that for the same price and still sell them for 60 bucks?
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #4
    Re: anyone want to promote cheap MPPT units?

    judging by his lacking any answers and the last time he has appeared that he may be attempting to spam the forum with this. i can't say for sure, but buyer beware if anybody acts upon it knowing there are many questions that go unanswered.
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  • System2
    System2 Posts: 6,290 admin
    #5
    Re: anyone want to promote cheap MPPT units?
    halfcrazy wrote: »
    120 bucks what about UL Listing can you do that for the same price and still sell them for 60 bucks?

    Sorry for the lack of replies. What is UL Listing? I have never heard of it, but I am interested.

    I am not attempting to spam the forum. I am looking for people what are interested in doing what I am suggesting. I know this seems vague, so it would be great to find someone who can program microprocessors, design circuit boards, order parts in quantities from chinese, assemble boards, ship boards to people... etc etc.. all of those, some of them... I can do all them but it gets aggravating at times, and I'm not really good at most of the things required; I know I can do it.

    I also feel like I may be missing or overlooking some important features, and maybe someone can point them out.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #6
    Re: anyone want to promote cheap MPPT units?

    i think if you are serious then you can see what features other mppt units have that you may wish to incorporate.
    as to ul and other certifications, this is a big safety issue that is very costly to have done. many local governments require only certified stuff and even insurance companies may refuse payment if such non compliant equipment is present even if it had nothing to do with any problems that may have been encountered leaving the burden on you to disprove said non compliant equipment did not cause a problem.
    there is still a market for such stuff as rvs and campers for example could use non certified stuff. another area might be for solar water pumping as i think the industry needs to lower prices for those controllers a bit.
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  • Kamala
    Kamala Solar Expert Posts: 452 ✭✭
    #7
    Re: anyone want to promote cheap MPPT units?
    geckosenator wrote: »
    ... What is UL Listing? I have never heard of it, but I am interested. ...

    The UL entry at Wikipedia.
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  • System2
    System2 Posts: 6,290 admin
    #8
    Re: anyone want to promote cheap MPPT units?

    I would be very interested in having a discussion about these units. I'm an EE, and pursuing a new BS in Renewable Energy. I am also a sailor with a Cascade 42. Shoot me an email and we can talk. I've set this system to be able to send me emails directly.
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  • benjamin
    benjamin Solar Expert Posts: 34 ✭
    #9
    Re: anyone want to promote cheap MPPT units?

    Well I can tell you one thing, if it's made in China I certainly wouldn't buy it. I'll pay twice us much for one built in the US.
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  • System2
    System2 Posts: 6,290 admin
    #10
    Re: anyone want to promote cheap MPPT units?

    I have begun researching a similar project, but I would prefer to use through-hole instead of smt components to appear to a wider DIY audience - and allow for breadboard prototyping.

    Please contact me via PM to discuss further.
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  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,102 ✭✭✭✭✭
    #11
    Re: anyone want to promote cheap MPPT units?

    Purchase a Schnider/Xantrex c series controller and you'll find a "Made In China" sticker prominently pasted on the side of the box. Sadly nearly everything electronic is made there these days.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

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  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #12
    Re: anyone want to promote cheap MPPT units?

    Not sure what your asking?

    C series controller are not MPPT types. Are you looking for a cheap, MPPT type inverter? Many are made here in the US.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
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  • Uncle Dave
    Uncle Dave Registered Users Posts: 24 ✭
    #13
    Re: anyone want to promote cheap MPPT units?
    littleharbor2 wrote: »
    Purchase a Schnider/Xantrex c series controller and you'll find a "Made In China" sticker prominently pasted on the side of the box. Sadly nearly everything electronic is made there these days.

    Yup.

    TO the OP - Im sure you are a smart talented guy - the thing is you have no idea what you don't know in this regard (don't feel bad you aren't remotely alone)

    As an employee of one of the few American technology companies that builds products in the US (we buy the odd part here and there)
    I can attest the fact that our Federal and local government pushed most manufacturing out of the US with miles of red tape it takes to satiate the growing number of regulating departments that take money for testing.

    We have an entire TEAM dedicated to certification.

    Where did that solder you used come from? It may not be allowable.
    You'll need to source it all the way back to the mine- we can't be supporting "conflict minerals" now can we!
    Every component needs to be sourced and documented all the way back to the smelter that raw material poured from.

    Building something for yourself is always great-IF you can do that, and maybe sell to a few to people who don't care about certs- awesome

    Building something to sell, is an entirely different matter especially globally, UL is just the tip of the iceberg.

    Selling to big public companies means their compliance department will want FCC emissivity testing for any microprocessor based device so they can insure your product doesn't become a " "mini radio station."

    Once you've finally finished all that if you comply then you can't change anything - even a model number- change the case for one thats cheaper or even a different color- you're looking at recertification.

    As to what features it should have thats the job of a "product manager" they determine what features a product should have at a given price point for a given market. You can do this yourself just buy figuring out who's got what in that price point today and weather or not you can offer the same features for less- or more.

    Im not saying you couldn't take a product form conception to market yourself, but you'd be way quicker to market shopping your skills somewhere that has the infrastructure for compliance testing.
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  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    #14
    Re: anyone want to promote cheap MPPT units?

    There are several open source MPPT controller projects.

    http://www.bing.com/search?q=open+mppt+controller&pc=MOZI&form=MOZSBR
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  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,102 ✭✭✭✭✭
    #15
    Just caught this: Whoever "Guest" (The OP) is here, for some odd reason their location on the left side of the page is identical to mine. I don't want any confusion as to who I am here. I don't have any relation to this person. I only recently updated my location status and it seems some wires got crossed here.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

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  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #16
    Now he has used my location and it ain't me neither!
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
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  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #17

    something very strange going on....???


    default_avatar_medium.pngGuest
    • Location: West Chilcotin, BC, Canada



    #1


     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
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  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    #18
    Definitely something strange going on. The forum kept telling me my input was "invalid", then posted it 3 times without my knowing. Weird!
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  • boomadge
    boomadge Solar Expert Posts: 25 ✭✭
    #19
    That's my location info that was first used, and I can assure it wasn't me !
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  • Mountain Don
    Mountain Don Solar Expert Posts: 494 ✭✭✭
    #20
    littleharbor2 wrote: »
    Just caught this: Whoever "Guest" (The OP) is here, for some odd reason their location on the left side of the page is identical to mine. I don't want any confusion as to who I am here. I don't have any relation to this person. I only recently updated my location status and it seems some wires got crossed here.


    What is strange is that I suspect that each of us registered members who are viewing this topic are seeing our own location info listed in the user info area in the OP. For that matter I believe every post that has "guest" as the user shows our own location info. (guest status is probably confered to any deleted member names if this software acts like others I know). So nothing to really worry about, IMO.

    The screenshot illustrates what I see when I'm logged in and view this topic....
    Attachment not found.

    Oddly when I logout and paste the url in I am unable to view the topic at all.

    Weird forum software thing.........

    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
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  • Mountain Don
    Mountain Don Solar Expert Posts: 494 ✭✭✭
    #21
    littleharbor2 wrote: »
    Just caught this: Whoever "Guest" (The OP) is here, for some odd reason their location on the left side of the page is identical to mine. I don't want any confusion as to who I am here. I don't have any relation to this person. I only recently updated my location status and it seems some wires got crossed here.


    What is strange is that I suspect that each of us registered members who are viewing this topic are seeing our own location info listed in the user info area in the OP. For that matter I believe every post that has "guest" as the user shows our own location info. (guest status is probably conferred to any deleted member names if this software acts like others I know). So nothing to really worry about, IMO.

    Attachment not found.

    Oddly when I logout and paste the url in I am unable to view the topic at all.

    Weird forum software thing.........
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #22
    playing games and jumping all over the map Mr Guest. Our own shared stalker
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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