Announcement

Collapse
No announcement yet.

Need some power at the cabin

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Mike90250
    replied
    I don't think there is a viable way to change inverter DC voltage. It appears it's easy to make charge controllers operate over a wide voltage range, but inverters have so much feedback happening because of variable loading and needing to greatly vary the input amps to keep the output voltage stable, the control circuits are tuned to just 1 voltage..

    Because of the rapid variation of input current, even 2 inverters wired in series to use a higher battery voltage, each powering a simple incandescent bulb, will quickly begin to oscillate in a bad way.

    Leave a comment:


  • Fordtrucksforever
    replied
    Just want to thank everyone for their input. With just a little bit of fill in the blank, I have a lot more insight about what my project will require to become a reality. One thing I was curious about regarding some inverters at hand. Two of them are 24 volt at 1000 watts. Another is 36 volt at 700 watts. Is there any way of making work with a 48 volt bank? I was hoping to tear into the 36 volt inverter and see what is needed to alter the battery voltage. May be a waste of time. But without trying something with these will never know what might work out. If they go boom, then to the scrap pile with them.

    Another dumb thought....maybe connect each of the 24 volt inverters to a pair of batteries in the 48 volt bank. Is this another really bad idea?
    Last edited by Fordtrucksforever; 10-28-2019, 02:13 AM. Reason: More questions

    Leave a comment:


  • PNW_Steve
    replied
    Originally posted by Fordtrucksforever View Post
    The only ones from Renogy I am aware of even close to $100 were 12/24 volt. Otherwise could have been a possibility. Any 48 volt chargers were around $300. I may just roll the dice on one of the off brands that has some support and decent reviews.
    You are correct. I overlooked the mention of the 48 volt battery bank.

    Leave a comment:


  • Fordtrucksforever
    replied
    The only ones from Renogy I am aware of even close to $100 were 12/24 volt. Otherwise could have been a possibility. Any 48 volt chargers were around $300. I may just roll the dice on one of the off brands that has some support and decent reviews.

    Leave a comment:


  • Mike90250
    replied
    Originally posted by PNW_Steve View Post
    I used the Renogy 40 amp MPPT. I paid just a bit over $100. I have been happy with it so far...
    Great, thanks for the info

    Leave a comment:


  • PNW_Steve
    replied
    Originally posted by Mike90250 View Post
    600w of solar PV is only 13A @ 48V, so a 30A controller would allow for future growth.

    Sadly, I don't know of any MPPT 30A controllers for less than $100. junk on amazon only has a sticker that says MPPT, without the real innards.
    I used the Renogy 40 amp MPPT. I paid just a bit over $100. I have been happy with it so far. Even with just one 300 watt panel has significantly reduced generator run time.

    Leave a comment:


  • Mike90250
    replied
    Originally posted by Fordtrucksforever View Post
    Thanks for your input. Is there any disadvantage to getting a larger than needed controller, besides the cost? Would just adding another smaller one work as well when increasing the number of panels?
    A larger controller allows for addition of more panels

    Adding a 2nd controller, you loose some control over charge setpoints, one controller will likely remain in Absorb for extra 30 minutes, you know the "Man with two Watches" never knows the right time.


    Can I tap into three of the 4 battery bank for 36 volt use without any serious issues?
    NO ! NO !

    Leave a comment:


  • Fordtrucksforever
    replied
    Thanks for your input. Is there any disadvantage to getting a larger than needed controller, besides the cost? Would just adding another smaller one work as well when increasing the number of panels?

    Can I tap into three of the 4 battery bank for 36 volt use without any serious issues?
    Last edited by Fordtrucksforever; 10-26-2019, 11:20 PM. Reason: Another Q

    Leave a comment:


  • Mike90250
    replied
    600w of solar PV is only 13A @ 48V, so a 30A controller would allow for future growth.

    Sadly, I don't know of any MPPT 30A controllers for less than $100. junk on amazon only has a sticker that says MPPT, without the real innards.

    Leave a comment:


  • Fordtrucksforever
    started a topic Need some power at the cabin

    Need some power at the cabin

    I have been reading a lot of good info here. So decided to join up and maybe get some education.

    For the last two years my focus has been on building a small cabin back in the woods. But now it is time to get some more reliable power for lighting and minimal load requirements. Running a generator much of the day, just for lights and fans is not too smart. It requires unnecessary trips to town for replenishing the fuel supply. My cabin is a two story structure at 800 sq ft. Very well insulated with 3 inch thick spray foam panels used on all exterior surfaces. Top, sides and bottom. Keeping the inside temp comfortable is not an issue. But still need some decent lighting and conveniences.

    Right now only spend two or three days a week living there, as I am finishing up everything. So my need for electrical power isnt really too demanding. For any high load needs, I have several generators ready to go. Decided to install some solar panels to power the led lighting, a ceiling fan, refrigerator, internet access, tv, and occasionally a small pressure pump for running water from storage tank.

    I have acquired several things getting ready to install. But could use some advice in one area I am in the dark to the details. Over the last year I picked up some panels, and storage batteries. May not be the best choice, but the expense was negligible.

    The following is what I am going to start with and hopefully will work out for a while. At least until finally connecting to the grid within the next year.

    2) Renesola 300 watt 24 volt panels. 72 cell, Voc 44.6, Vmp 36.8, lsc 8.69A, lmp 8.2A.
    4) Data safe storage batteries 12HX540. 12v, 540W/cell 15 min.

    The batteries may not be the best choice for use here, but they cost next to nothing and an almost unlimited supply of them. They are huge and weigh over 100 lbs a piece. Takes forever to run one down.

    My thoughts are wire the panels in series for 72 volt output at 300 watts. Batteries also in series for a 48 volt bank.

    I am in the dark on size controller may be needed. Hoping to get away with a smaller 30 or 40 amp model. Plans are to maybe add two more solar panels, if everything works out.

    My budget unfortunately for the controller needs to stay close under $100.

    I also have a bunch of commercial UPS units that am planning to cobble any salvageable to use for inverters, if possible. I have seen other people use them, and for the little time I would be relying on power might work out without spending too much out of pocket. Other ideas?

    Thanks in advance for anything you have to offer.
    Last edited by Fordtrucksforever; 10-26-2019, 01:45 AM.
Working...
X