1200 Watts of solar and 600 AH of Battle Born

[E12Cheng]

Well here we go. Just ordered the batteries today and the solar panels arrived yesterday. My system will use the Victron 3000k inverter charger and the victron 100 amp charge controller for the panels. Replacing the #10 cable from the roof to the basement with two sets of #2 welding cable. Looks like the 6 batteries will fit in the current battery locker with only an additional 40 lbs compared to the two lead acid installed now. Worry a little about the cold weather and the battery location so I ordered the electric blankets for the batteries. Never know how far north we will get on our adventure.

[AZ Traveler]

Welcome to the forum!

Post some pics and let us know how it works when you get it all installed. Sounds like a nice setup.

[Mudchief]

Welcome to the forum.

[jeffba]

Welcome to the Forum. Without pix it did not happen

[Sparky55]

Very nice. Where did you purchase the heating blankets?

[E12Cheng]

Battle born sells them as well. They are designed for their battery so they should keep the batteries chargeable in cold weather.

[Bigboomer]

Looking forward to seeing more about your install. Good luck. I love the Victron line and how it integrates with itself.
Welcome to unlimited freedom from the grid!

[E12Cheng]

We will be full timing in Jan and the solar will help keep us comfortable. Have a soft start on the way as well. May try to use the a/c in the Captains cabin.

[Sparky55]

Perfect. I plan to get one for a/c with heat pump. If that works well I’ll get a second one for the bedroom air

[artfuldodger]

Check the wire requirement from panels to solar controller. #2 sounds too heavy. Wouldn't # 4 do the job just as well? I'm not an expert but have been using solar for 3 yrs. now and know that overkill can be a problem too. Anyway, enjoy your setup and welcome to the moc.

[PNW Fireguy]

In this scenario the only downside to over sizing the wire between the panel combiner box and the charge controller is cost. The larger the wire the less the voltage drop all things equal. I would however suggest verifying your charge controller terminals are rated and sized for #2 wire. I have a pretty robust charger and my terminals are rated for #4 AWG max.

[E12Cheng]

Thanks for the heads up. My charge controller is a Victron smart solar charger mppt 150/100. The Pv connections are 35 mm and I think that is #2. My run from the combiner box to the charge controller is 25 feet. I think 1 set of #2 would work but I had the shop run two sets.

[Ctopher61]

Was thinking the same thing. Number 2 wire sounds like it might create more resistance than anything else. Just my thoughts, without taking pencil to paper and doing a calc.

[E12Cheng]

A couple of folks asked why I was using two #2 cables for my run from the roof to the basement. The run will end up being 25 feet.
A #2 AWG cable has a 33.6mm cross sectional area. Two #2 AWG cables would equal 67.2 MM cross sectional area. A 2/0 AWG cable has 67.4mm cross sectional area close to the two #2 AWG cables I’m installing.
Using a minimum conductor size calculator, Copper at 20 feet in a DC circuit at 12 volts with 90 amps requires a 2/0 copper conductor. With the 1200 watts of solar on the roof I don’t think I will capture the entire 100 amps so two # 2 AWG cables should be adequate for this install. Please if my math or assumptions are off let me know. The PDF is a drawing of the system I'm installing

[PNW Fireguy]

Your concept is not correct. However the result works out for you to address voltage drop. There are some great tutorial videos regarding solar system wiring, wire protection on the alt e website.

[scottz]

Originally Posted by Ctopher61

Was thinking the same thing. Number 2 wire sounds like it might create more resistance than anything else. Just my thoughts, without taking pencil to paper and doing a calc.

The bigger the wire, the less the resistance; if you have the muscle to handle it.

[jetskier]

10awg would work from the panels to the controller if you run half the panels in series and tie them in parallel at the combiner. If you're doing a full parallel system, you will need the larger size. 2 or 4 awg from the controller to the batteries is optimal for the 100a controller output at 13-14 volts

My 855w array operates at around 50-55v at 17 amps in peak conditions feeding the controller. Well within the permitted current limit of 10awg wire (30amps).

[PNW Fireguy]

Originally Posted by jetskier

10awg would work from the panels to the controller if you run half the panels in series and tie them in parallel at the combiner. If you're doing a full parallel system, you will need the larger size. 2 or 4 awg from the controller to the batteries is optimal for the 100a controller output at 13-14 volts

My 855w array operates at around 50-55v at 17 amps in peak conditions feeding the controller. Well within the permitted current limit of 10awg wire (30amps).

While true why would one not take advantage of the larger wire size for lower voltage drop?

[jetskier]

I have the 150/85

[E12Cheng]

Just received my DC distribution. This is set up for 8 batteries but I will only use 6. Quality equipment from Victron. I'm pleased so far.