Beginniners question about battery bank !

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!

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