Solar set-up: 2nd opinions needed

[Nookies]

Hiya guys

It's been a while since I last checked in due to relocating from Coffs Harbour NSW to Yorketown SA & what a wonderful journey we had. We had to do 2 trips to 1st bring all the items for storing then the 2nd trip was with all our camping/traveling gear. We also went 2 different ways to SA, 1st through Wagga Wagga & the 2nd through Broken Hill. But enough of that now. Since my last check in I had to divert all the funds for a solar set-up towards moving & now finally I am back to the beginning & thankfully I am more informed.

Requirements/Restrictions:
We do not plan to travel long distances in a fortnight (again ) so there is not enough on-road activity to utilise a DC-DC charger. We also are living in our CT until we find a dwelling fitting our budget. In short, I view this as a small off-grid solar set-up running (almost) 24/7 as opposed to intermittent usage for holidays. Currently, we are at my sisters property in the front paddock with 240V grid. Everything we get has to be able to be used as an off grid system when we find a place to live.

We only have 2 power drains, none of which are 12V so 3 incl the inverter (proposed 600/1200 or 1000/2000)
- AC 80lt Freezer @10A 12VDC (when on & not incl 20/25A spike power up)
Usage: Opened 2ce per day - mid-day change over of saltwater ice in a Techni-Ice esky & taking out a meal for dinner.
- AC TV & amp @15A 12VDC (constant when on)
Usage: On @dinner time when gen is on & through to bed time (aprox <3hrs on battery)
- Anything else (Microwave, PC etc) will be only used when the gen is charging/floating batteries @1-2hrs every day @dinner time/no sun.

Proposed solar set-up
- 4x 12V (19V) 100W panels wired in either 24V (38V) banks = 2x 24V (38V) 200W @10.5A max
or 48V (76V) bank = 1 x 48V (76V) 400W @10.5A max
(can add extra 2 or 4 x 100W panels @12V system & expandable through 24V/ 36V/ to 48V)

Proposed battery management
- MPPT: (12/24/48V 60A) able to take up to 140V w/o major loss @60A http://www.ebay.com.au/itm/MPPT-60A-sol ... 4#shpCntId
- Inverter: either 600/1200(<-- hopefully) or 1000/2000 @12V (24V when we have more batteries) http://www.ebay.com.au/itm/Large-Shell- ... Sw2XFUhlKO
- Battery Protector: Variable cut off @12.4V cut in @12.9V (+/-10%) between battery & inverter. http://www.jaycar.com.au/p/AA0262
- 240V Delay on: So the system can start when panels are activated automatically. Inverter will start 5s before connecting the freezer/load. =http://au.rs-online.com/web/p/time-del ... 285155/ RS
- De-Sulfator: Eventually when we get good batteries. http://www.ebay.com.au/itm/battery-desu ... SwxYxUvlmU

Batteries
- Will start with a 100AH used AGM battery & whatever we can scrounge initially, don't care about life. Can't afford both set-up & batteries in one shot.
- In 6 months will be 2 x 200AH banks (400AH) either @12V or 24V

Cables (both (+)&(-) treated as 1 cable):
- 2B&S connecting both battery banks to 2x 175A Anderson plugs keeping both banks isolated.
Un-bridged when drawing from gennie for AC charging (40A charger for each bank all 2B&S connections).
Bridged when drawing from MPPT, Batteries & Inverter.
- 2x 2B&S (2-3M) cables connecting banks to the management box via 2x 175A Anderson
1 side is the MPPT, Bat protector, Inverter, Delay on
Other side is the AC charger side
Using a marine/4x4 battery switch - Bank 1 (maintenance)/ Bank 2 (maintenance)/ Off/ Both (Solar/MPPT). Off will be used before switching
cables to AC charging.
- 10M of 6B&S twin core to connect array to MPPT with 50A Anderson (max current is 21A from array)

Safety:
- AC Breaker between inverter & freezer
- Safety switch between inverter & TV
- DC breakers between every major DC stage - (Bank > Anderson) - (Anderson > Management box) - (Inverter > box) - (MPPT to box)
- a few V meters to keep an eye on the batteries.

[edit] I figure that to keep the life of the battery as best as I can, the battery protector will cut out at 12.4/12.5VDC (turning the inverter off during the night & triggering the safety switch to turn off awaiting reset) & cut in at around 13V (sun up), turning the inverter on 5s before the freezer is turned on. The safety switch prevents any other item drawing from the Inverter when the system cuts back in. The abundance of Volt/Ampere headroom is for future expansion.

After all of that (& thank you for sticking with it), is there anything that stands out as being unsafe, overboard or missed?

[robcaz]

Hi Sasha & Seiya,

It sounds as if you have most things covered. You will find some great advice to interconnecting batteries at http://www.smartgauge.co.uk/batt_con.html

[Nookies]

TY for the reply.

Method 3 was going to be what I was aiming for as adding a battery would be a matter of of simple addition with no rewiring. In doing this, I may use more cable than what I need & eventually I think method 4 being the best of all configs. It was awesome to see a professional write it out that way because it's just 1 more thing I now know that I didn't before so ty so much for that link.

Do you think I could get away with the 600/1200W inverter running a 160W freezer & 200W audiovisual system? I've seen the freezer spike up to 300W when cutting in for about a second but it could be higher & the digital meter not refreshing fast enough to register it. The Amp also has a smallish spike as well.

BTW, I may be persuaded into selling Seiya for LiFePo

[robcaz]

with a little forward thinking on what your ultimate setup will be, you can allow for the future expansion as the system grows when money allows.