ADVICE NEEDED for a NEWBIE...

[xflip227x]

Okay here's the story...I'm looking to set up a small solar backup generator. I live in Queens, New York; having said that, on my property, I don't have much room. However, the panels are mounted on an adjustable mount...attached to the brick wall, which faces South. I want to connect the system as a 24v to keep the wire size requirements down...basically have 4 groups of 2 batteries in series at 12 volts & 100 AH producing a 24 volt battery bank at 400 AmpHours capacity. If I'm not mistaken, that would store 9600 watt hours at 24v. I do understand that it will take a while to charge the batteries using the panels that I currently have, but I do plan to upgrade later...

The components I have are as follows:

2 Renogy 100 watt monocrystalline solar panels - Plan on upgrading later
8 100ah Vmaxtanks AGM 12v batteries
1 Sunsaver 15amp MPPT charge controller
1 Victron Energy Battery Monitor
1 GoPower 30amp Transfer Switch
1 GoPower Smart Battery Charger GPC-35 (35amps)
1 GP-DC-KIT2 Inverter Installation Kit for 12V 600-1000W & 24V 600-1800W Inverters
1 GoPower 24v 1500w pure sine wave inverter.


The advice I need is basically...how to wire everything together. I've used the tools on freesunpower.com to guestimate the wire sizing, but I'm still at a loss.
1) What size (gauge) cable would I need to run from my panels to the charge controller (distance = 25ft) for 24v at 5.75amps? Then from the charge controller to the battery bank (distance = 15ft)?
2) What size (gauge) battery interconnect cables should I use?
3) What size (gauge) primary wire should I use to connect the peripherals (12v dc socket etc)?
4) What size fuses should I use? Any recommendations on the brands/type? either in-line or into a fuse panel?

Any help/advice here would be much appreciated.

[Mike90250]

apartment or house? batteries inside or outside ?

Why a boatload of parts hard to wire together? Why not a integrated inverter/charger like the XW series? They have a built-in transfer switch, midnight makes a nicely integrated ePanel to containing the wiring in.

Since batteries start to die when they leave the factory, just get the smallest you can get by with, as you use the system and the first batch fails, then you are ready for the larger batch.

[xflip227x]

apartment or house? batteries inside or outside ?

Why a boatload of parts hard to wire together? Why not a integrated inverter/charger like the XW series? They have a built-in transfer switch, midnight makes a nicely integrated ePanel to containing the wiring in.

Since batteries start to die when they leave the factory, just get the smallest you can get by with, as you use the system and the first batch fails, then you are ready for the larger batch.

They're on an attached house. I already had the parts... hence the "boatload." Batteries are inside the house.

[Mike90250]

Wire gauge vs length - use this calculator:

http://www.solarpaneltalk.com/showthread.php?2312-Wiring-interconnect-goodies-amp-volt-drop-loss-calculator

Wire batteries in series, here's an article about the perils of parallel.

http://www.smartgauge.co.uk/batt_con.html

PV - combiner box w/breakers - controller - fuse - batteries.

You don't have enough PV currently to keep all those batteries healthy. You may need a mains powered charger too.

Be sure your controller is set for AGM style batteries, and does not perform automatic EQ cycles.

And likely more, this is what comes to my mind at midnight.

[SunEagle]

You have two issues from what I see. Wiring that many batteries in parallel will probably shorten their life due to imbalance during charging and discharging. Parallel wired batteries is never a good thing to do.

Second, that 200 watts of pv panel will not be enough to properly charge a 400 AH battery system. Even on a good day you may get 10 amps out of those panels which will only provide a C/40 charge rate to the batteries which is too low.

My suggestion is to only use 2 of those 12volt batteries in series with those 200 watts of panels and sell off the other 6 batteries until you can increase your system size (pv watts = battery Ah).

And as Mike suggested you should also get a generator and battery charger for AGM type batteries when you do not get enough sunlight to charge.