RV system up and running

ZoNiE · November 2014

I feel sort of... underwhelmed. It's all so... anti-climactic.

I have been studying, reading, posting, learning, And now have my system up and running.

3X Kyocera KC130GT panels wired in Parallel
1X Midnight Kid
1X Whizbang Jr
1X temp probe (they need to use more industrial cabling and make it longer)
1X Outback 500A shunt
2X Interstate GC2 batteries
1X Custom made combiner box with:
3X pushbutton 10 A breakers (0ne for each panel)
1X pushbutton 35 A breaker for combined load.
All panel and charge wiring is 10AWG. Longest run is Kid to batteries, about 20 ft (one way). Panels to combiner are 10-15 ft (ow) and combiner to Kid about 15 ft (ow).

It's all installed in my travel trailer.

Nothing exciting to report. It all seems to be working. I initially had to fumble my way though the menus to fix the AH setting from 416 to 216 AH, but it is all now set right. I am leaving the roof vent fans on tonight to run a typical overnight draw on the batteries to see what my SOC is in the morning, and then see how the system does. My panels are flat mounted, on a slightly curved roof, with one of them sort of facing away from the sun a wee bit. Front of the trailer is facing east, that panel is on the north side.

The batteries are 4 years old, and getting weak, so this is a good checkout.

I guess time for a new project... (Alde Hydronic heat install)

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ZoNiE · November 2014

Re: RV system up and running

as of 8:45 this morning, SOC is 100% already.

Either the fantastic vents on low are not much of a load, my kid isn't setup right, or this setup is working like it should.

Cariboocoot · November 2014

Re: RV system up and running

ZoNiE wrote: »

as of 8:45 this morning, SOC is 100% already.

Either the fantastic vents on low are not much of a load, my kid isn't setup right, or this setup is working like it should.

Do not trust any battery monitor right out of the box. Check the SG and see if the batteries really are getting to 100% SOC.

Reed · November 2014

Re: RV system up and running

Looks good

You probably have room for another two or three panels.

Just turned on the Fantastic Fan to see what is its draw. It showed 0.2 amps at 48 V nominal or about 10 W. So you should not have dropped much in stored energy. Hard to tell since we are currently pulling in 700 W with a clear blue sky in southern NM (Las Cruces).

Left the Dometic fridge on AC overnight (we will have clear skies for the next week) and were down -3.5 kW-hrs (30% DOD)

What are a glycol water heater and a Adle Hydronic boiler (to lazy to google at this moment).

As noted on earlier posts, we are full-time RV'ers that primarily boondock/bushcamp and solar was the only way to go.
Reed and Elaine

Photowhit · November 2014

Re: RV system up and running

ZoNiE wrote: »

1X temp probe (they need to use more industrial cabling and make it longer)
//
All panel and charge wiring is 10AWG. Longest run is Kid to batteries, about 20 ft (one way). Panels to combiner are 10-15 ft (ow) and combiner to Kid about 15 ft (ow).

This may indicate a problem, your charge controller should be close to your batteries. I'm amazed you could have this long a wiring runs in a small trailer.

If you charge controller thinks it's sending 18 amps at 14 volts to your batteries, but your using 10 gauge wire, you will have a 5% voltage drop so what the battery will get will be @ 13.3 volts. This is the reason for having the CC close to the batteries, so you will need to change locations or run heavier wire.

Cariboocoot · November 2014

Re: RV system up and running

I did a quick check on what Photowhit was talking about.

If the three panels can put out 25 Amps and you've got 10 AWG wire for 20 feet the V-drop is about 8%, which is far too much. You should either shorten that wire run (if at all possible) or increase the size to 6 AWG. Otherwise your controller could be entering Absorb when the batteries are really a full Volt lower than it thinks. Check this out to be sure.

scrubjaysnest · November 2014

Re: RV system up and running

We run the Fantastic vent fan on low and one O2 cool on low all night and our SOC will be very close to 100%, usually between 98 and 99 %. And yes you may need to the wire size to 6 AWG. We have a 40 foot run from the truck to batteries when going down the highway using 8 AWG but there charging is a little different then the controller handles it. Typically we hook the solar panels up after three days of use off the batteries without moving the camper.

Photowhit · November 2014

Re: RV system up and running

I really have a hard time figuring out all the issues of having such small diameter wiring and reading the SOC at the Charge controller. Voltage reading in the morning before you have much/any current running to the battery will be pretty close to accurate, since the wiring is carrying such small amounts of current, Though if reading at the Whiz Bang and measuring amperage, the O2cool should draw @10 watts(including inverter) or about 120wh or about 10 amps from your battery bank, so the figure should be lower than that, your inverter may draw 20 watts an hour as well, of course these may be 12 volt loads?

It may have many different things going on including over charging the battery since it doesn't 'see' the voltage, or just not charging since it's setting the charging voltage too low since it will loose voltage in the wiring going to the batteries.. 'Coot might have some ideas on this... I'd be sure to change the wiring to reduce the voltage drop to under 2%.

Cariboocoot · November 2014

Re: RV system up and running

It matters most at the beginning of the Absorb stage when Voltage and current will be at their highest (usually). If at that point you have a lot of V-drop between the controller and batteries it will start Absorb when the batteries aren't really up to the Voltage the charge controller thinks they're at.

ZoNiE · November 2014

Re: RV system up and running

Reed wrote: »

Looks good

You probably have room for another two or three panels.

Just turned on the Fantastic Fan to see what is its draw. It showed 0.2 amps at 48 V nominal or about 10 W. So you should not have dropped much in stored energy. Hard to tell since we are currently pulling in 700 W with a clear blue sky in southern NM (Las Cruces).

Left the Dometic fridge on AC overnight (we will have clear skies for the next week) and were down -3.5 kW-hrs (30% DOD)

What are a glycol water heater and a Adle Hydronic boiler (to lazy to google at this moment).

As noted on earlier posts, we are full-time RV'ers that primarily boondock/bushcamp and solar was the only way to go.
Reed and Elaine

Not really, I could squeeze two Kyocera 65W panels from the same series (If I can find them cheap) but that is it. One in the back, and one up front offset a bit from the two on the right. I would have to move where the TV antenna parks. north of that, the roof curves downward.

Photowhit wrote: »

This may indicate a problem, your charge controller should be close to your batteries. I'm amazed you could have this long a wiring runs in a small trailer.

If you charge controller thinks it's sending 18 amps at 14 volts to your batteries, but your using 10 gauge wire, you will have a 5% voltage drop so what the battery will get will be @ 13.3 volts. This is the reason for having the CC close to the batteries, so you will need to change locations or run heavier wire.

I'll keep it like this for now. It was not a matter of trailer size, but where and how I could run the wiring without making a new roof penetration and where I could fit my combiner box. I also didn't want the charge controller on my pillow. Walls in this trailer are 2" thick styrofoam with aluminum framing and bonded fiberglass and luan inside.

I also have the shunt and the WBJR right next to the batteries, on a 3' long #2 wire. Shouldn't the WBJ be measuring the current at the battery?

Running anything bigger into the Kid would be tough and would require lugs or #10 pigtails. I may also move the combiner closer to the kid, and that would eliminate about 15 feet of cabling.

At the end of the day, if this setup keeps my two GC2's charged based on my minimal usage, with the long runs and less than ideal panel mounting, the so be it. I'm into this for less than $2 a watt. Batteries not included, as the RV had/needs them anyway.

Cariboocoot · November 2014

Re: RV system up and running

Seems to be a misunderstanding about where the longest wiring run is. Our concerns are based on this sentence from the OP:

Longest run is Kid to batteries, about 20 ft (one way).

That's the one that could cause problems.

Photowhit · November 2014

Re: RV system up and running

Just a guess, you have a 5th wheel and want to see the display inside the trailer... Batteries in the up front storage with shunt whiz bang...

In time you will decide the charge controller is doing it's job and only look at it when you have multiple cloudy days or some oddity in the system.

ZoNiE · November 2014

Re: RV system up and running

Photowhit wrote: »

Just a guess, you have a 5th wheel and want to see the display inside the trailer... Batteries in the up front storage with shunt whiz bang...

In time you will decide the charge controller is doing it's job and only look at it when you have multiple cloudy days or some oddity in the system.

Almost. I's just a TT, but yeah, the batteries are up front. I will probably move the CC when I install an inverter. They will reside in the front compartment. If I had a 5er then it would all be in the usual front genny compartment, which I do not have.

I wish the Kid had a remote display instead. All in one box is nice, but a better design would be to have the control module plug into the front or be able to be used remotely with a cable. Many 3 phase motor drive inverters are like this. The gameboy is plugged into the front, but can be remoted or removed to prevent users from tampering with them.

Reed · November 2014

Re: RV system up and running

Photowit

We primarily check the monitors to decide which form of power/energy management we need to utilize:
1. Full solar insolation for the next day we will run Dometic fridge on solar/battery bank. We will also use the electric water heater during the day.
2. Good solar insolation, we run the fridge during daylight only
3. Overcast or rain predicted, we turn off the inverter since it runs about 50 W
4. Four days snow. Pretty much do not user inverter and stick to propane.

Our two bits on cabling. Our panels are 2 sets of 3 in series (then parallel) so that the voltage is 90 V to controller.This means less voltage/power drop, using a 45 amp controller (90 V means the amperage is 14 A for 1300 W instead of 114 A at 12 V, and utilzing smaller cabling. I think Cariboocoot has discussed this several times.

Use the Gennie compartment for battery bank/inverter/controller etc.\ as ZoNiE notes
Reed and Elaine

RV system up and running

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