PV Solar Power System

[Dee Bee]

Those experienced in PV electrical systems

I am gathered materials an am about to start on a solar powerd off grid system. My goal as I start is not to power a house etc. Only a small office. A light, lap top, possibly a printer.

Please comment on my drawing.



The batteries have been given to me. I have purchased the Charge Controller on ebay along with the inverter. Switches are from HF and Radio Shack. Almost all the wire is 10 g. The mains are 6.

Helpful ideas and questions will be most appreciated.

Dee Bee

[wannabefree]

Just a thought on the batteries. Parelleling batteries is not recommended, though it is done. When you do it, you should be certain that all batteries are in the same condition and rated the same capacity. When you replace batteries, you should replace all of them at the same time. Since the batteries were given to you I am suspicious that they may be used. Generally, when people parallel batteries they limit it to two, you have six. As mismatches in the batteries develop over time, some will charge at different rates. One may take a full charge, others may not charge completely. When the charger is not charging batteries the fully charged one will attempt to charge the not-so-fully charged batteries. This sets you up for really poor battery life.

You would be better off with one or two higher capacity batteries, free or not.

[Guy]

Dear DeeBee,

http://www.Rvsolarelectric.com has a large amount of useful info on their site re wiring diagrams, sizings, draws,etc.

[dreadcptflint]

It should work. I worked on something similar seven years ago. The article is http://www.solwest.org/news/Fall01.PDF. If you are serious then I would contact solwest or the guys from homepower to see how it is working all these years later and if they would do anything differently.

[Dee Bee]

Here are a few pics of my rig

Dee Bee

[nawlinsteardrop]

What size power inverter do you have?

Just wondering if the 10 Gauge wire is enough.

[ARKPAT]

Dee Bee
PostPosted: Sat Apr 11, 2009 9:14 pm Post subject: PV Solar Power System
Those experienced in PV electrical systems

I am gathered materials an am about to start on a solar powered off grid system. My goal as I start is not to power a house etc. Only a small office. A light, lap top, possibly a printer.

Please comment on my drawing.



The batteries have been given to me. I have purchased the Charge Controller on ebay along with the inverter. Switches are from HF and Radio Shack. Almost all the wire is 10 g. The mains are 6.

Helpful ideas and questions will be most appreciated.

Dee Bee

Looks like you are off to a good start Dee.
One suggestion is to make sure the TOPs of the batteries are very clean ( dust and or film ). They will discharge across the dust and or film on them ( you might be surprised how much ).
SUNELCOhas a very good tutorial ( several others also ). I have a limited budget so I started out small and grow as I save electricity and money on my electric bill and place that savings into more solar stuff.




Pat

[Dee Bee]

What size power inverter do you have?

Just wondering if the 10 Gauge wire is enough.

My inverter is 2400 watts

Each battery holds 35 AH I have run 10 g wire from each batter to a terminal block.

From the terminql block to the inverter is 6 g.


Dee Bee

[nawlinsteardrop]

I think the wire on the on the inverter should be like 2/0 Wire.

Here is a wire gauge chart..

http://www.powerstream.com/Wire_Size.htm

OO 0.3648 9.26592 0.0779 0.255512 283 190 200 Hz
0 0.3249 8.25246 0.0983 0.322424 245 150 250 Hz
1 0.2893 7.34822 0.1239 0.406392 211 119 325 Hz
2 0.2576 6.54304 0.1563 0.512664 181 94 410 Hz
3 0.2294 5.82676 0.197 0.64616 158 75 500 Hz
4 0.2043 5.18922 0.2485 0.81508 135 60 650 Hz
5 0.1819 4.62026 0.3133 1.027624 118 47 810 Hz
6 0.162 4.1148 0.3951 1.295928 101 37 1100 Hz
7 0.1443 3.66522 0.4982 1.634096 89 30 1300 Hz
8 0.1285 3.2639 0.6282 2.060496 73 24 1650 Hz
9 0.1144 2.90576 0.7921 2.598088 64 19 2050 Hz
10 0.1019 2.58826 0.9989 3.276392 55 15 2600 Hz
11 0.0907 2.30378 1.26 4.1328 47 12 3200 Hz
12 0.0808 2.05232 1.588 5.20864 41 9.3 4150 Hz

You will be doing 200 amps of power transmission. So I think the inverter should call for 2/0. Maybe a little less if run is less than 1 or 2 feet total.

What does the manual say? You may have a large voltage drop in the circuit.

How has your system been working? looks pretty cool. I wish I could get my hands on some of these batteries. LOL

I see you are using the Shunt Type GPR-25 Regulator. The new PWM regulator is out now and will improve charge performance. I think unless you have an issue, don't upgrade.