Now I have mounted 5 sets of Harbor Freight kits....was going with 8 or 10 wire, found half a roll of 14/3 type SO 600 volt....think it was replacement wire from the welder....Does any one know if it can be used to the CC?

Found a BZ mppt 500 on eBay ....think $229.00 ...or just save for the Rouge?  Any sites for MPPT controllers at a fair price? what to get it soon.

Making combiner box.....does inline 20 amp car fuse go between combiner box and cc ?

After cc is there 20 amp brearker box {are they a  different kind of breaker than dc} to battery bank?

After I get cc will be saving for batts.

This will be  a 12 volt system, am going to pick up 2 Sams Club golf cart batteries and add 1 every other week. Will this screw my bank up? I mean not adding 12 volt at time?

I have 7 sets HF kits 5 are going to be connected what amps would that be approx.?  My guess is amps 12 to 14 not much so will definately have to add.

I have a 750 Harbor Freight inverter.....need help been learning here but getting jumbled in the head....Thanks

Views: 364


Reply to This

Replies to This Discussion

You will only be able to add two 6 volt batteries at a time. And realistically you want to purchase them at the same time. Keeping the battery bank with only matching type and age batteries is a big bonus when it comes to life span of the battery bank. 

Hi Mike,


The type SO 14-3 cord is designed for portable tools, such as the welder you mentioned, and is UL listed for both indoor and outdoor use.  That AWG-14 wire is made up of 41 AWG-30 solid strands of wire and can conduct up to 18 amps.  See one manufacturer’s specifications.

This wire chart gives 14-AWG (41/30) a resistance of 2.516 ohms per 1,000 feet, or 0.002516 ohms per foot.

Use the following formula to find the voltage drop between your solar panels and your charge controller: V = I x R.  (V = unknown, I = current the wire will carry, and R = number of feet between the solar panels and the charge controller x 0.002516). 

Plugging in your proposed numbers: 12 amps out of the solar panels x the length of the wiring run.  Once you calculate the length in feet and the total ohms, your answer will be the voltage being “dropped” by the current in the wire.  Starting with 23.5 Voc of the solar panels, minus your answer, will give the voltage available at the input to the charge controller.

Example: 500 feet between the panel array and the charge controller.  500 feet out for one wire, 500 feet back for the other wire equals 1,000 feet of total resistance.

V = 12 amps x 2.516 ohms (per 1,000 feet) equals 30.192 volts.  This means that it takes 30.192 volts to force 12 amps through those 2.516 ohms of wire.  The HF solar panel Voc of 23.5 volts won’t do it.  It will force a little over 9 amps, but with only about 11 volts available at the CC.  Can’t charge a 12-volt battery with 11 volts.

Try using the formula, and if you have problems, let me know what the length of wire between your panels and charge controller will be (as that pesky crow flies), and I’ll help you.

Quote: “Making combiner box.....does inline 20 amp car fuse go between combiner box and cc ?”

Yes, it goes in the combiner box, not at the charge controller, to protect the wiring between the combiner box and the charge controller.

Quote: “After cc is there 20 amp breaker box {are they a different kind of breaker than dc} to battery bank?”

I assume this 20-amp breaker is between the charge controller and the battery bank.  The only household AC circuit breaker that can also “break” DC (that I am aware of) is the Square-D “QO/QOB” breaker.

If you don’t use the Square-D brand, then use something like this.

Other AC rated breaker brands will tend to weld its contacts together when it tries to trip.  Not Good.

Quote: “I have 7 sets HF kits 5 are going to be connected what amps would that be approx.?  My guess is amps 12 to 14 not much so will definitely have to add.”

Five sets of 3 panels = 15 panels.  15 panels at a theoretical 1 amp each = 15 amps.  15 amps x 0.77 (Dale Marshall’s approximate de-rating multiplier) = about 12 amps.


Hillbilly Gene


Thanks...I have to unscramble my brain a second.....From panels to cc 22ft.

I will use the 14 wire on something else.

Hello Mike,


Sorry for the late reply, I will throw out some thoughts on most of your questions.....


1.     Using 8 or 10 awg wire from the combiner box to the CC would be preferable over using 14/3. That is just my general statement without knowing the distance between the combiner box and the CC. Also what are there plans for expansion in the future.. If so you will want to use wire that is suited for the end game in your build. Otherwise you will be rewiring everytime you expand the solar panels.


2.      I use a BZ MPPT 500 and think they are great. They are an entry level MPPT controller. They do not have a detailed display like the Rogue, but and priced accordingly. I don't think you will go wrong with one of these. They have very good performace, but not alot of info on their display.


3.     I started out using fuses but found that it was much easier to use breakers. You can get DC breakers in alot of sizes and they are easy to reset or turn off when you are working on your system. I use this kind. There are many others but these are plentiful and cheap. I put them between the combiner box and the CC  and then between the CC and the batteries and finally between the batteries and the inveters. I place each on the the positive lead. This will break the circuit if any one of your components fail.


4.     Ray is correct.. You should add the batteries in sets of two. You can add them one at a time, but that will require you to rewire each time with a series / parallel connection. If you add them in sets of two it is much easier.


5.    Five kits connect together.. you are about right... 12 to 14 amps is in the ball park.


6.     Inverters are another discussion.  Lets talk about the uses of the system before we purchase an inverter.


Hope to see more questions.





Thanks for the Help....Moe

1 Going for the 8 gauge wire

2 Rouge ordered

3  THANKS nice to know about the breakers.....never new something like that existed. 

The smallest I see Is 80A......Would I use this even though I would only be around 12 to 14 amps ? 

Going to save for 4  EGC2 duracell golf cart batts....Sams club.



The 80 amp for anything your drawing from the battery. But if you use them to fuse the connection on the Rogue. You only need 30 Amp on the Input and 40 amp on the charging side.

Got the Rogue.....anything I need to check?.....should have the breakers/fuses shortly....Gettin batts next wk. Starting to get puzzle pieces. Gonna make a drawing/pic of my planned use of this system soon as I have time.....Think you could give me your opinion?  Good/Bad  Wrong or Do not do that.


I have #8 awg from combiner to rouge 22 ft. not connected yet ....Can I use # 6 AWG from rouge to batts with 40 amp breaker?  Can I use the 6 wire for the series wires on the batts? Right now I have 4  6 volt golfs charging on a different set of HF 45watt. Right now I have them seried with some jumper cable wires I cut and put ends on. So what would be better 6 or jumper wires.

What would be the best bang for the buck    24 volt or 12 volt system?

I have 47 volt and about 8 amp at combiner.

Built battery box just need to hook up a fan.....on the rouge aux. still tryin to figure that out....Think it has to go to a switch then to a fan.  Can I take a fan from a junk computer some one was throwing out so I grabbed it just for the fan?

Is it correct for 2 Ground rods...1 for Rouge and 1 for panels on roof?

Thanks much..... getting that quiet confidence

Hello Mike,


You have moved along nicely.


The 6 awg from the controller to the battery bank will be great. I would not use the 6 to connect the batteries in series. I would actually go to the local auto parts store and buy some battery cables that are 2 awg. You can get them very inexpensively and you can get them with the ends already connected. This will be much better overall.

The question about 24v or 12v is not as easy. The 24v will be more efficient for power management, but if you plan of using inverters the 24v inverters are a bit more expensive but can be found without too much hassle.  Now if you are talking about wiring the panels.. for sure 24v is the way to go. You can leave the battery bank at 12v and use standard inverters while the panels are wired for 24v.

I don't have much input on the fan hookup, but I do think one grounding rod is fine. You can ground both items on it.




© 2016   Created by Renewable Ray.   Powered by

Badges  |  Report an Issue  |  Terms of Service