Planning a small solar system - concerned about if I'm doing things right.

[SR20DETDOG]

Hi everyone! I'm new here and would like to get some input and opinions on my plans for a small solar system as this will be my first one.
Also I wasn't entirely sure where to post this so I just put it here.

My goal is to take everything in my room (which isn't a lot) off-grid. The system will basically consist of,

1 x 80w Solar Panel - Already purchased
Specifically it's a Powertech folding panel with built it charge controller (prevents overcharging and has a battery level indicator) Living in Australia I get a lot of sun nearly all year round and I'm nearly positive 80w will be plenty.

1 x 12v 100ah AGM Battery - Not yet purchased
I have my eye on for AUS$275, seems like a decent deal, free delivery too
I'd like this to last a long time so I figure this would give me a good 30ah to use.

1 x 800-1500w modified sine 12v DC-240AC Inverter
While I would probably use only a few 100w at any one time I figure if I get something bigger now it leaves me headroom for growth and avoids the need to buy something bigger down the road. I would eventually like to be able to power things like microwaves and coffee machines, high wattage but only for minutes at a time.

Since the solar panel has it's own charge controller would there be any problems with simply connecting it and the inverter to the battery and being on my way? Or are there other things to consider here?

Thanks in advance 

[birdhouse]

welcome aboard!

the only potential issue i see is with the battery and charge controller choice.  AGM batteries are sealed, and water cannot be added to them.  many charge controllers have different setting for different battery types.  IE: lower voltage for AGM or SLA, yet higher voltage for FLA. 

i have no idea how well the built in CC is going to play with the AGM battery you've chosen. if the setpoints are too high, it will boil that AGM dry and then it's fried.   if it were me, i'd go with a flooded battery.  much more forgiving, and water can be added as needed.  also, i'm sure you could bypass the panels CC and use an aftermarket one with more adjustability. 

also, MSW inverters can cause havoc on certain items.  cordless tool charges can have issues, as well as other things.  PSW is a lot more expensive, but worth it in my opinion. 

adam

[DamonHD]

For my big 12V gel battery bank I use the specific gel setting on my solar controller, though I did use an older gel battery on some sort of random settings for at least a couple of years without terrible damage it seems.

Rgds

Damon

[Flux]

I agree with the others. If your panel has a sufficiently accurate voltage regulation for AGM batteries then fine.

If it happens to be one of those panels with fewer cells sold as self regulating then it is a no go.

Again a true sine inverter is a better device but if your requirements are not demanding a MSW can be perfectly ok. There are loads that object to them but they are often small sophisticated electronic items . Big power hungary things with heaters are not bothered. Microwaves tend to produce less heat and have to be run a bit longer, it may be that the most recent versions with electronics in place of the high voltage transformer may be more fussy, I don't know.

Flux

[Crispy]

Based on the max watts of a few hundred you say you will be using, your inverter rating will be fine and the panel output seems to match your goal of 30AH daily draw on your battery.

All 3 components must be matched to each other to a degree, but more important to your load. I suggest you make a list of all items you plan to power with your system and document the watt usage of each and multiply by hours of daily use. You may come up short unless the few hundred watts is of short duration with much lower numbers being the norm.

My family room uses about 250 watts for 2 laptops, flat screen tv, dvr, router, modem and 1 cfl light. At 12 volts your 30 AH would be used up in less than an hour and a half.

A precise calculation of your power consumption is crucial to designing your system to meet your needs. A bit of a cushion won't hurt either

Crispy

[OperaHouse]

I think you ought to get a new battery for your car and use the old one for this project.  The truth is you don't know what you need and won't till you get some experience with your system.  Likely the best output from that 80W panel will be 45W.  Get a good monitoring system to avoid a deep discharge situation.  By learing the limits of a restricted system you will learn what you really want.  Things are never as they seem.  I run an entire camp on two used car batteries.  All batteries have a limited life.  No need wearing out a good one on practice.

[XeonPony]

Simple advice?

1 - Get a 130w (I'd personaly jump ahead with a 230w) Monocrystalin panel and toss the 80w

2 -  Skip the AGM you aut to be able to get 2 6V 230AH golf cart batteries for next to nothing

3 - Get a Morning star Sunsaver 15 mppt

4 - As others have said, pure sin wave is ideal, but I been stuck with a modified one and frankly had no mentionable issues 1Kw cont, 2Kw surge, use a 200Amp fast acting fuse and 2 guage wire.

Now with that you have the basics of a system that leaves you allot of growth room befor you need to upgrade, you will all ways end up using power to some extent at night and seems most fail to add that in to the charging equation.