charge controller that can handle 29 volt input?

John XW NYJohn XW NY Solar Expert Posts: 50 ✭✭✭✭
I need a inexpensive charge controller to run my dc freezer. My solar panel is 120 watts and put out 29.5 volts. The battery is 12 volt Trojan 195 AH, I have and ASC 12/16 charge controller but it is not functioning correctly and only handles 26 volts.

Can someone tell me which one can do the job for me without breaking the bank?

thanks JD


ANY NAWS TECHS OUT THERE THAT CAN GIVE ME A HAND??? HELP!!!

THANKS!!

Comments

  • BB.BB. Super Moderators, Administrators Posts: 31,171 admin
    Re: charge controller that can handle 29 volt input?

    The Morning Star MPPT 15 amp controller will do fine--Not cheap at $234 plus shipping.

    There are other PWM controllers (like the Xantrex C40) that will handle the higher voltage just fine (Voc max = 125 vdc, others are lower)--will not collect as much power from the array. At $151--it is not real cheap either.

    Sort of need to know your exact panel and where you are to figure out the Voc (cold) and Vmp (hot) to make sure that the controllers meet your requirements.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: charge controller that can handle 29 volt input?

    There are quite a few controllers that will handle 29 volts, the only controllers that will give you more than about half power out of the panel are the MPPT type, such as the one that BB mentioned.
  • John XW NYJohn XW NY Solar Expert Posts: 50 ✭✭✭✭
    Re: charge controller that can handle 29 volt input?

    GUANGYI TECH - 120 WATT model gyp- 120m, voc 29.76v,short circuit 5.41 amp, maxpower voltage vmp 24.96, max current imp 4.81 amp tolerance +5%

    this is the panel specs if you can add other options let me know.

    Thanks 4 the advice so far, im thinking about it

    i guess the real question is mppt or regular c40 style.

    :roll::cool: JD
  • mike95490mike95490 Solar Expert Posts: 9,098 ✭✭✭✭✭
    Re: charge controller that can handle 29 volt input?

    With your high PV voltage, a old style PWM controller will only give you half the PV wattage. You need to use a MPPT style controller.
    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 ,

  • BB.BB. Super Moderators, Administrators Posts: 31,171 admin
    Re: charge controller that can handle 29 volt input?

    When Vmp is much different than the battery bank's charging voltage--you have a lot of losses in a PWM converter.

    You can estimate the power into the battery bank during charging between MPPT and PWM:
    • MPPT: 120 watts * 95% eff * 1/14.4 volts charging = 7.1 amps charging current
    • MPPT: 120 watts * 95% = 114 watts into battery
    • PWM: 4.8 amps Imp = 4.8 amps battery charge current
    • PWM: 4.8 amps * 14.4 volts = 69 watts into battery
    No right or wrong answer here--It depends on your needs and the $$$ you have available.

    And, in the end, there are lots of other losses too (wire, battery efficiency, inverter efficiency, solar panel output in real life, etc.)... So, assume you have a nice summer day (5 hours of noon-time strength sun) with a MPPT controller--the useful `120 VAC power out an inverter:
    • 120 watts * 5 hours * 0.52 system derating = 312 Watt*Hours per average summer day
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • John XW NYJohn XW NY Solar Expert Posts: 50 ✭✭✭✭
    Re: charge controller that can handle 29 volt input?

    Thank you very much gentleman. I will consider the advice. One more consideration is that the battery is Trojan 195 ah so maybe to much power is overkill for it since it only holds so much. The Sundanzer freezer i believe uses like 35 ah a day which is minimal(me thinks :-).


    God Bless, JD
  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: charge controller that can handle 29 volt input?

    35 AH x 12 volts = 420 watt-hours.

    So you will not get enough to run it with a standard controller.
  • BB.BB. Super Moderators, Administrators Posts: 31,171 admin
    Re: charge controller that can handle 29 volt input?
    John XW NY wrote: »
    Thank you very much gentleman. I will consider the advice. One more consideration is that the battery is Trojan 195 ah so maybe to much power is overkill for it since it only holds so much. The Sundanzer freezer i believe uses like 35 ah a day which is minimal(me thinks :-).

    Oh no... Your battery is just about right for your load... 3 days of no sun, and 50% maximum discharge:
    • 35 AH per day * 3 days * 1/0.50 = 210 AH recommended battery capacity
    However the amount of solar panel may be a bit light. Assuming you are anywhere near Binghamton, NY... You are looking at 4 hours of sun (or a bit less) 9 months of the year:
    • 120 watts * 4 hours * 0.77 panel/controller derating * 0.80 battery eff = 296 WH per day
    • 296 WH per day / 12 volts = 24.6 AH per day
    Depending on your needs (summer only, 12 months of the year)--it would not hurt to double your solar power.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • John XW NYJohn XW NY Solar Expert Posts: 50 ✭✭✭✭
    Re: charge controller that can handle 29 volt input?

    yep well im not buying another panel. thats it im done with it. lol

    maybe the mppt is the best choice then to maximize the panel array power.

    hey in the winter i can always back it up with my ac charger plug in style!

    i live up in Woodstock Ny,

    have you noticed the sun is getting stronger and more white light? or is it just me?
  • John XW NYJohn XW NY Solar Expert Posts: 50 ✭✭✭✭
    Re: charge controller that can handle 29 volt input?

    Hey naws ive decided to take your advice on the mppt. I see it listed on ebay for 215 dollars with free shipping if you can match the price i will buy it from you. If you don't believe me check ebay yourself. Im giving you guys the chance to buy it from you. You should be able to match the price.

    My email is [email protected]. If interested get right back to me . I want to give you the sale, fair is fair. Ok thanks jd
  • BB.BB. Super Moderators, Administrators Posts: 31,171 admin
    Re: charge controller that can handle 29 volt input?

    John,

    Windsun does not really watch this forum for business related issues. You should contact NAWS directly.

    I don't know anything about his price matching policies--but he (and this forum that he funds and maintains) will be there if you have any questions...

    And this forum will be here in any case whomever you end up purchasing from to help the best we can.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • newenergynewenergy Solar Expert Posts: 291 ✭✭✭✭✭✭
    Re: charge controller that can handle 29 volt input?

    In the winter in Woodstock NY can't you just put the freezer outside and then it won't need any power?
  • mike95490mike95490 Solar Expert Posts: 9,098 ✭✭✭✭✭
    Re: charge controller that can handle 29 volt input?
    John XW NY wrote: »
    Hey naws ive decided to take your advice on the mppt. I see it listed on ebay for 215 dollars with free shipping if you can match the price i will buy it from you.


    The question is - does the ebay seller actually have it in stock? You will not really know till after you deliver the $ first.

    Are you SURE it's the MPPT version, $215 is the PWM version.
    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 ,

  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: charge controller that can handle 29 volt input?
    John XW NY wrote: »
    Hey naws ive decided to take your advice on the mppt. I see it listed on ebay for 215 dollars with free shipping if you can match the price i will buy it from you. If you don't believe me check ebay yourself. Im giving you guys the chance to buy it from you. You should be able to match the price.

    My email is [email protected]. If interested get right back to me . I want to give you the sale, fair is fair. Ok thanks jd
    Whether I believe you or not, we do not match eBay prices. But don't call us for tech support or for warranty if things don't work out...
  • John XW NYJohn XW NY Solar Expert Posts: 50 ✭✭✭✭
    Re: charge controller that can handle 29 volt input?

    No its the MPPT version , not pwn you don't believe me check yourself.
    here is the link http://cgi.ebay.com/Morningstar-Sunsaver-MPPT-12-24V-15A-ChargeController_W0QQitemZ140386219250QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item20afabb4f2

    check 4 yourself..

    if someone else can afford to sell at this price you should 2.

    I think prices should be level across the board. I don't see why there is such wide array of prices with today's technology it is very easy to find out what is the best price and since economy is doing bad and people are hurting. Companies should give everyone the best deal possible.

    I have bought from NAWS before and probably will again. I bought my Hydrocaps from them when they sold them. Now they do not sell them anymore you have to buy direct to get them.

    I do appreciate everyone's help, you guys are awesome.:cool:;):D
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: charge controller that can handle 29 volt input?

    if you think that offer is so great then get it. why do you expect naws to match it?
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: charge controller that can handle 29 volt input?
    John XW NY wrote: »
    if someone else can afford to sell at this price you should 2.

    I think prices should be level across the board. I don't see why there is such wide array of prices with today's technology it is very easy to find out what is the best price and since economy is doing bad and people are hurting. Companies should give everyone the best deal possible.

    I have bought from NAWS before and probably will again. I bought my Hydrocaps from them when they sold them. Now they do not sell them anymore you have to buy direct to get them.

    I do appreciate everyone's help, you guys are awesome.:cool:;):D

    If we were talking about two retail outlets in the same town you'd have a point. But in two different states you get operating conditions of different overhead included taxes, labour, and energy costs. Not to mention quality of service. :D

    Gasoline around Vancouver is $1.149/L. Up North it's $1.019/L. Same gas, only the price goes down when they truck it up the canyon. Go figure.
  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: charge controller that can handle 29 volt input?
    John XW NY wrote: »
    if someone else can afford to sell at this price you should 2.

    Yes we could, if we only wanted to make $4 on the deal, not counting our shipping costs. I guess we could sell at a loss and make it up on volume.

    Perhaps you should participate in his forum and see what info he provides... :blush:
  • mike95490mike95490 Solar Expert Posts: 9,098 ✭✭✭✭✭
    Re: charge controller that can handle 29 volt input?

    That's the 15A MPPT controller... somehow I was thinking you were looking at the 60A version
    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 ,

  • John XW NYJohn XW NY Solar Expert Posts: 50 ✭✭✭✭
    Re: charge controller that can handle 29 volt input?

    Uhmm i think you guys are missing the point and have taken it personal. This is buisness we are talking about. Instead of arguing why something costs more when it is unjustifiable. I don't care the price of gas or any of that stuff. Those are all just really side arguements and I did not come here to argue any of this stuff anyway. Then the conversation gets into political undertones and nastyness which really have no place here as far as i am concerned.

    Whoever said i want to make NAWS match the price is also incorrect. I wanted to give NAWS my buisness and allow them to make the money on the deal. Does that make me a "Bad Guy", for wanting the best price. I do not think so.

    Now that i have done more research im not even sure what you have told me about using this controller is correct. Included is a post about the controller which underlines issues about it that were failed to be mentioned. I will add it to my post right after this one because i need to switch my computer. but i think it will shed some light on the topic and whether or not this technology has really even been properly implemented by the manufacturer.
  • John XW NYJohn XW NY Solar Expert Posts: 50 ✭✭✭✭
    Re: charge controller that can handle 29 volt input?

    heres the post about problems with the sunsaver, funny how no one mentioned them to me, only the pluses not the minuses.

    http://forum.solar-electric.com/showthread.php?t=3460&highlight=sunsaver+mppt+problems


    now since i am a neophyte at this stuff why would someone recommend something that needs an expert to reconfigure settings etc etc . When i really want something to plug in and play. It would only make matters more complex instead of easier convenience which is what i want. ( and demand as a customer) from the products i buy.
    I think too many cooks spoil the pot, much like the political hooha going on these days. Im not interested and it does not solve the problem for me which is lack of transparency and truth.

    Jah Guide I JD
  • BB.BB. Super Moderators, Administrators Posts: 31,171 admin
    Re: charge controller that can handle 29 volt input?

    I am not sure what the question about that thread is... For the small 15 amp MPPT -- The Remote Battery Temperature Sensor is MANDITORY for best operation.

    The rest of the questions where looking at second level issues (was controller reprogrammed by somebody in the middle--don't know)...

    And the actual problem:
    bajasurfer wrote: »
    It turns out I've got more than solar issues to deal with.

    I finally found out that my buddy Dave had used the inverter 2 days in a row with TV/xBox+12V lighting on a July weekend, when I didn't go...I figure ~1.5+ Kilowatts per day.

    I took the battery bank out yesterday & brought it home. Specific gravity measured 1.1-1.14 @ ~80°F on all 12 cells. All my measurements say they are just plain dead. It's charging as I write this, but I am sullen due to little hope for recuperation... and I'm angry because it was so avoidable.

    Does anyone think that dropping both batteries on Dave's head will make him understand what he's done?

    His partner killed the bank with over discharging...

    I am not sure I saw anything that could be laid at the feet of the charge controller except that the Mfg. soft sells the $28 RBTS...

    Yes, marketing many times changes things to options to reduce the entry level price (oh--you want a full sized spare tire too?).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • John XW NYJohn XW NY Solar Expert Posts: 50 ✭✭✭✭
    Re: charge controller that can handle 29 volt input?

    Good Answer Bill,

    So you are saying that wont happen if i buy one? I think it would be a major pain in the butt. As far as i am concerned it should have easier controls on the unit to make any adjustment needed. Makes sense right? Im still debating whether to get an mppt or just a cheaper one because i dont really even know how much im going to use it. But i did order hydrocaps today.

    As far as the price issue i should not have to defend why i expect the best price from whoever i buy my stuff from. That is kind of silly if you ask me. but who asked me anway. LoL

    There should be an inexpensive one that can handle up to 30 volts from the solar i am looking around there seems to be quite a few. I would hate to pay 200 bucks and then not have the thing work right. That would get me really mad (edited by niel with the word mad substituted).

    Anyway i do appreciate the helpful advice and you guys really do give good support.
    thanks JD8)
  • BB.BB. Super Moderators, Administrators Posts: 31,171 admin
    Re: charge controller that can handle 29 volt input?
    John XW NY wrote: »
    Good Answer Bill,
    I try (or as my wife says--"I am trying"). ;)
    So you are saying that wont happen if i buy one? I think it would be a major pain in the butt. As far as i am concerned it should have easier controls on the unit to make any adjustment needed. Makes sense right? Im still debating whether to get an mppt or just a cheaper one because i dont really even know how much im going to use it. But i did order hydrocaps today.
    I am the last guy to tell you something won't happen with Brand XYZ mppt controller... I don't use any of them with my Grid Tied system (I choose a small inverter/generator as my backup power device as I am cheap and could not justify for a once in a 100 year earth quake as my major power failure).

    I have designed equipment for many years too--and I appreciate the trade-offs that designers and companies make to bring stuff to market. Make is "simple" with no adjustments--somebody always needs it tweaked.

    Make something with a lot of adjustment--A risk of crashing the controller/causing damage elsewhere.

    Make a computer interface and choose a fairly rugged interface like 485/ModBus--And now people need to purchase a $55 interface adapter for their computer to "talk with" their $234 solar charge controller:

    wind-sun_2094_38937500Morningstar RSC IE-485 to Serial Adapter

    It is a tough battle...

    As far as the price issue i should not have to defend why i expect the best price from whoever i buy my stuff from. That is kind of silly if you ask me. but who asked me anway. LoL

    I don't think anyone was upset by your question--The forum (and NAWS) is just not setup for a "bidding" process to offer for sale equipment from NAWS.

    From Wind-Sun's comment, his profit appears to be around $4 for the price you requested... For whatever reason (and I am not in anyway connected with NAWS--I am just here to help with spam control)--It is not worth it to NAWS to offer at that price.

    His choice... Your choice...

    No matter who (whom?) you purchase from--the forum will be here and we will do our best to help with any questions you may have... Obviously, none of us here are speaking for NAWS or any manufacturer through this forum--just folks trying to help.
    There should be an inexpensive one that can handle up to 30 volts from the solar i am looking around there seems to be quite a few. I would hate to pay 200 bucks and then not have the thing work right. That would get me really pissed.

    Agreed--But I can tell you that solar power is not cheap--and all of us here have made many "educational purchases" over time... In solar, $250 is not an "expensive" lesson.
    Anyway i do appreciate the helpful advice and you guys really do give good support.

    I do like NAWS/Wind Sun's 99% satisfaction guarantee:
    99% Satisfaction Guarantee

    What happened to the other 1%? Well, we are not perfect yet. We do our best, but occasionally things don't go quite as planned. We will do everything reasonable to make it right - but please don't expect us to warranty the inverter you just dropped in the ocean. We do not guarantee to offer the lowest prices on the internet - you cannot offer good service and the lowest prices. When promoting your business, quality should come first. Quality and service is our main concern and we won’t cut the corners required to offer the “cheapest price”. Our prices are competitive and we don't think that cutting prices to the bone will improve our customer service. If you want the lowest possible prices, and don't expect to ever need customer support or technical assistance, then we are probably not a good fit. We find it interesting that nearly half of our calls to technical support are for systems bought from our competitors...

    Is the Morning Star 15 amp MPPT controller the best one out there--probably pretty close at that power range.

    Is it cheap--Probably not. Does it work--Yep.

    If you ever plan on a larger array for your DC battery charging--You may want to look at the Morning Star "TriStar" MPPT charge controllers in the 45/60 amp size... From what I understand, you can plug in a Ethernet cable to your network, and they are ready to go (even have a web server inside).

    Many people find that they start "small" and that growing their system is expensive--very little is reusable a the systems expand. (larger charge controllers, larger battery banks you should not mix old/new cells, new wiring, rewired/larger arrays, larger panels as they are cheaper per watt vs small panels, etc.)...

    -Bill "just my personal opinion" B.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: charge controller that can handle 29 volt input?
    John XW NY wrote: »
    There should be an inexpensive one that can handle up to 30 volts from the solar i am looking around there seems to be quite a few. I would hate to pay 200 bucks and then not have the thing work right. That would get me really pissed.

    Handling up to 30 volts is not the problem The problem is that you are using a 30 volt panel to charge a 12 volt battery. As explained at the start of this thread - you CAN use one of the cheaper non-MPPT ones - but you will get less than half power out of your panel. A non-MPPT controller will give you the 12 volts at the rated panel amperage, which is about a 60% loss.
  • John XW NYJohn XW NY Solar Expert Posts: 50 ✭✭✭✭
    Re: charge controller that can handle 29 volt input?

    Yeah well i know Solar ain't cheap, my XW system wasn't inexpensive believe me.
    But it did come in very handy two weeks ago when the snowstorm hit and knocked out the power for 3 days. It really felt good having the backup power and not needing gas to do it either. It has been a interesting experience so far and definitely a learning experience, Ive used the XW configuration tool as well and that is kind of neat to say the least.

    Its all relative i guess .....

    God Bless
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