Beginniners question about battery bank !

pyana1pyana1 Solar Expert Posts: 39 ✭✭
I've got 500 watts PV , 4 Trojan t105s (225 AH) ran in parallel then series for 450 AH.

I've read online that one shouldn't discharge their battery bank completely; so here's where I need some help.

I have a deep freezer and wanted to know for how many hours could i keep it running, Im using the freezer soley to produce ice in Haiti where the sun is always shining; so I'm assuming about 4-5 hours would be enough to make some nice solid blocks of ice at the freezer's coldest setting; would it be better to run the freezer while the sun is up, or should i let the batteries charge during the day and run the freezer at night?

I ran the freezer once before shipping it off to Haiti for about 12 hours with a watt-meter and got about 800 plus watts within that 12 hour time frame (misplaced paper with information, could have hour-by-hour wattage)

Comments

  • PhotowhitPhotowhit Solar Expert Posts: 5,804 ✭✭✭✭✭
    pyana1 wrote: »
    I've read online that one shouldn't discharge their battery bank completely;
    You should get a good charge controller and let it worry about your battery health and ignore the people telling you this...
    pyana1 wrote: »
    I have a deep freezer and wanted to know for how many hours could i keep it running, Im using the freezer soley to produce ice in Haiti where the sun is always shining; so I'm assuming about 4-5 hours would be enough to make some nice solid blocks of ice at the freezer's coldest setting; would it be better to run the freezer while the sun is up, or should i let the batteries charge during the day and run the freezer at night?
    Always better to use the energy before it is stored, since you will waste a good percent of it trying to store it.
    pyana1 wrote: »
    I ran the freezer once before shipping it off to Haiti for about 12 hours with a watt-meter and got about 800 plus watts within that 12 hour time frame (misplaced paper with information, could have hour-by-hour wattage)

    Are you talking about watt hours of energy? This will vary a good deal (less with the well insulated freezer) depending on the ambient temperature and the load, if you fill it with 8 gallons of water the compressor will run longer than if you fill it with 1, You will need to experiment to find how much you can expect to freeze in a day.

    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.
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    pyana1 wrote: »
    I've got 500 watts PV , 4 Trojan t105s (225 AH) ran in parallel then series for 450 AH.

    I've read online that one shouldn't discharge their battery bank completely; so here's where I need some help.

    I have a deep freezer and wanted to know for how many hours could i keep it running, Im using the freezer soley to produce ice in Haiti where the sun is always shining; so I'm assuming about 4-5 hours would be enough to make some nice solid blocks of ice at the freezer's coldest setting; would it be better to run the freezer while the sun is up, or should i let the batteries charge during the day and run the freezer at night?

    I ran the freezer once before shipping it off to Haiti for about 12 hours with a watt-meter and got about 800 plus watts within that 12 hour time frame (misplaced paper with information, could have hour-by-hour wattage)

    Discharging batteries completely will kill them VERY quickly. Aim for never discharging them more than 50%, better still for good battery life, don't take them below the 80% full state, and recharge them as soon as possible - - - leaving batteries sitting not fully charged will also ruin them. Try to recharge every day.
    As to expecting solid ice in 5 hours, it will take time to cool the freezer itself before it can begin to freeze water.
    Don't assume it will do anything in 4 to 5 hours - - run a test and then you'll know.
    And yes, it's better to have the freezer doing it's hardest work while the sun is shining. If your panels provide enough power, they will run the freezer plus recharge your batteries while the sun shines.
    Also, be very aware that the freezers power consumption per 24 hours, will depend on how hard it has to work. That is - - it's one thing for it to just have to keep things frozen - - a totally different thing if it's loaded with things to be frozen!
  • hemmjohemmjo Solar Expert Posts: 90 ✭✭
    Pyana,

    I work with a mission right next door in the Dominican Republic. We have a system as listed below at our place. We have 1300watts of panels and 4-225amp batteries similar to you. We use a charge controller and inverter to run refrigeration and a few other things. We even have a small manual type washing machine, but it is only run in the mornings when it is going to be a bright sunny day.

    When the days are sunny, panels can easily keep the batteries charged. But if we have even one cloudy day the batteries go below 60% just running the fridge. We have to shut down the fridge to keep from ruining the batteries.

    Is your freezer 12 volt?

    Good Luck,

    John
    Two systems in the Dominican Republic  http://villagemountainmission.org/
    installed Feb 2014 at 19.796189° -70.893594°, Classic 150 + WBJR, KISAE SW1210, MN Battery Monitor, IOTA DLS 55/IQ4,  4- Solar World 275w, 4-6v x 225ah Trace Batteries
    installed Feb 2015 at 19.795733° -70.893372°, same components  as above
    Honda PowerMate PC0497000, 7000/8750w generator - powers the well and chargers maybe once a week






  • hemmjohemmjo Solar Expert Posts: 90 ✭✭
    Pyana,

    I work with a mission right next door in the Dominican Republic. We have a system as listed below at our place. We have 1300watts of panels and 4-225amp batteries similar to you. We use a charge controller and inverter to run refrigeration and a few other things. We even have a small manual type washing machine, but it is only run in the mornings when it is going to be a bright sunny day.

    When the days are sunny, panels can easily keep the batteries charged. But if we have even one cloudy day the batteries go below 60% just running the fridge. We have to shut down the fridge to keep from ruining the batteries.

    Is your freezer 12 volt?

    Good Luck,

    John
    Two systems in the Dominican Republic  http://villagemountainmission.org/
    installed Feb 2014 at 19.796189° -70.893594°, Classic 150 + WBJR, KISAE SW1210, MN Battery Monitor, IOTA DLS 55/IQ4,  4- Solar World 275w, 4-6v x 225ah Trace Batteries
    installed Feb 2015 at 19.795733° -70.893372°, same components  as above
    Honda PowerMate PC0497000, 7000/8750w generator - powers the well and chargers maybe once a week






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