6.4KW pv System 90% installed-question

Gitchee Gumee Kid

My 6.4KW pv system is about 90% installed.
Components:

30 Kyocera 215W panels ( two pole mount )
Xantrex XW6048 Inverter
Xantrex MPPT 60 ( two )
Sm battery bank -->four 200AH AGM's
8KW diesel generator 120/240 vac

Location NW Wisconsin

Question-->At a 25 % max depletion of the batteries could I power let's say a freezer thru the night?

I'm seriously thinking of going the extra mile and get 8 more batteries.

TIA

GGK

BB.

Re: 6.4KW pv System 90% installed-question

What is your daily load (Watt*Hours per day)?

We usually suggest people not get too many batteries unless they have a specific need (for example, fuel is hideously expensive and/or difficult to get to the site).

Even then, when adding "more batteries"--frequently more solar panels are needed to really recharge the bank well...

Then there is the whole cost of replacement 5-8 years or so down the line (or, heaven forbid, somebody takes out the entire battery bank a year later when some heavy loads where left on during winter).

-Bill

Cariboocoot

Re: 6.4KW pv System 90% installed-question

Let's see ... 200 Amp hours @ 25% DOD is 50 Amp hours. Times 48 Volts nominally is roughly 2400 Watt hours. Or about what I use to run the whole cabin daily, including refrigerator.

That much panel would support 800 Amp hours or so of battery.

BB.

Re: 6.4KW pv System 90% installed-question

Also, what is your peak load/surge load?

If that is a 200ah 48 volt battery bank, that would support about 2,000 watts peak and 4kW surge loads.

With a 6kW array, you should have a minimum 600ah 48 volt battery bank--otherwise you are probably going to have over voltage issues at the battery bank (I think is a F49 inverter fault)

-Bill

niel

Re: 6.4KW pv System 90% installed-question

the simple answer is yes it could power it over night and will drop the battery capacity further even though it most likely would not exceed the 50% dod point.

i would recommend 4 more batteries for as it is you are pumping quite a bit of power into those present 4 batteries at around 100a give or take. if they are concordes they can take it, but i would not be comfortable with that arrangement. any large total loads to the inverter may also bog down the batteries so that aspect has to be kept in mind too.