Help me design my solar/battery bank for camper

[1leglance]

I have a wiring question....
The Victron shows a connection for the panel, for the battery, and for load....so instead if connecting my fridge and anything else to the battery I should connect them all to the Victron in a bus bar or something?
And in this manner if the Victron has a full battery or more power than the battery can take (bright mid-day sun) the does it give that excess to the load and save the battery?
Is this "load" output regulated so I don't blow up my fridge? I couldn't figure that out.
Thanks to everyone

 

[pdavitt]

I have a wiring question....
The Victron shows a connection for the panel, for the battery, and for load....so instead if connecting my fridge and anything else to the battery I should connect them all to the Victron in a bus bar or something?
And in this manner if the Victron has a full battery or more power than the battery can take (bright mid-day sun) the does it give that excess to the load and save the battery?
Is this "load" output regulated so I don't blow up my fridge? I couldn't figure that out.
Thanks to everyone

Yes, bus bars are the way to go. The screw compression terminals on the 75/15 aren't large enough to hook up much.
If your charge profile is setup correctly, the 75/15 should add any excess power it produces into the system to power loads.
The URL for the manual is: https://www.victronenergy.com/uploa...-75-10-75-15--100-15-EN-NL-FR-DE-ES-SE-ul.pdf

Pat

 

[dwh]

Load terminals are mostly unused in what we do. They are generally limited to around 10a max. They are also protected by a Low Voltage Disconnect (LVD) - when the battery is drained down to a certain voltage, the load is shut off.

That's useful for something like a nightlight on a solar/battery powered electric gate, but pretty much useless otherwise.

No, the charge controller doesn't "divert excess power". The solar feeds the battery, the load terminals run off the battery (hence the LVD). Diverting excess power is something wind controllers can do, since you can't just switch off a spinning windmill without causing problems. Solar controllers don't need it - you can just switch solar off.

 

[john61ct]

The load terminals on Victron are fine for turning off whatever non-essential devices when the batt gets depleted.

Same as a generic LVD.

Limited amps though.

 

[pdavitt]

I think everyone is correct, except me in my statement about use of the "load" terminals on the 75/15. They provide 15A and do have a LVD built in. I'm not used to dealing with the smaller charge controllers with a Load output, so I should have kept my mouth shut.
Thanks to others for correcting me. I still think one should read the manual, including me, before asking a question or especially, answering one.

Thanks everyone,

Pat

 

[dwh]

I wasn't correcting you, Pat. What you said was true. I was responding directly to Lance's questions.

Prolly should have quoted him but I got lazy.

 

[pdavitt]

It's ok. I didn't give technically correct information. I'll try not to do that in the future.
Pat

 

[dwh]

And to clarify Lance's understanding...

If the solar is capable of producing more than the battery can absorb, and there are loads running, the solar power will flow to both the battery and the loads. That'll happen whether the loads are connected directly to the battery, or connected to the battery through the charge controller's LVD protected load terminals.

The loads will draw power with a greater "pull" than the battery, so enough load could reduce the amount of power available for the battery to absorb.

If the loads are greater than the solar can supply, all of the power coming from the solar will get used by the loads and whatever else is needed to make up the difference to supply the loads will come from the battery.

 

[pdavitt]

And to clarify Lance's understanding...

Great explanation. Did I see "Tail End Charlie ", I was a Navy pilot.
Pat

 

[dwh]

Dad and uncles were Air Force. I was Boy Scouts Air Explorers and Civil Air Patrol.

Grew up in the 'Ocean of Air'.

 

[pdavitt]

Dad and uncles were Air Force. I was Boy Scouts Air Explorers and Civil Air Patrol.

Grew up in the 'Ocean of Air'.

Great place to grow up. I have a friend with a Stearman that I get to fly every once and awhile.
Pat

 

[1leglance]

So we have the system laid out as
2 6v Golf Cart batteries
Blue Sea A-MCR
Victron 75/15
and now to pick solar panels...

I am concerned about my GVWR with my new 2017 Tacoma DCLB and between the 400lb camper, fridge, 150lbs of batteries, camp gear and such...I want the lightest solar panels. And now hearing about the multi-panel concept I am looking for advice on picking panels.
The Snap Treehouse roof is aluminum and has 2 lengthwise L tracks and I plan to make whatever mount needed.
My thought is thin flexible panels doing the series/parallel thing and maybe have an extension cord to pull them off the roof when I want to park in the shade.

So let's hear some recommendations and thanks as always for all the help

 

[dwh]

I let my license lapse in my late 20's (30 years ago). New baby, single dad...just couldn't afford it. Not like when I was a teen and my group affiliations would get me a Cessna 150 for 12 bucks an hour wet.

 

[luthj]

There are some lighter glass faced and metal framed panels available, I don't have any experience with them. Home/RV mount panels generally have a rigid extruded aluminum frame, and a glass top. They can be heavy. A 160W panel would be around 25lbs or so. A 100W panel around 16lbs.

Flexible panels have two varieties. One is semi-flexible with a thinner glass face, and no frame. These are hard to find and expensive last I checked. The more flexible panels have a plastic top face. These are less than half the weight, but are note durable or long lasting. 2-5 years is the expected lifespan out in the elements, compared to 30 years for a traditional panel. Take note that flexible panels do no handle regular flexing well, as the cells or interconnects can crack. I have seen flexible panels melted badly from high resistance internal connections. So they must be treated with some care. The plastic type flexible panels will last a lot longer if they can be bonded to a stiff substrate, such as metal sheet, plastic, etc. As this helps to counteract the thermal expansion/contraction between the cells and the plastic face.

In my experience shade is either a lot, or none. I would pick the panel(s) that fit your rig best for the max wattage you can fit/afford. If that is a single 300W grid tie panel, great. If that is 3 or 4 smaller panels, and/or a suitcase portable panel, that works great.

 

[pdavitt]

So we have the system laid out as
2 6v Golf Cart batteries
Blue Sea A-MCR
Victron 75/15
and now to pick solar panels...

I am concerned about my GVWR with my new 2017 Tacoma DCLB and between the 400lb camper, fridge, 150lbs of batteries, camp gear and such...I want the lightest solar panels. And now hearing about the multi-panel concept I am looking for advice on picking panels.
The Snap Treehouse roof is aluminum and has 2 lengthwise L tracks and I plan to make whatever mount needed.
My thought is thin flexible panels doing the series/parallel thing and maybe have an extension cord to pull them off the roof when I want to park in the shade.

So let's hear some recommendations and thanks as always for all the help

I don't think you've stated how much "roof top" real estate you have available. The option to going with multiple low voltage panels, is to install one high voltage panel. If you have the space to install one 40" by 67" panel that weighs 40lbs. look at the LG Solar NeON R LG360Q1CA5 360 Watt 36V. They ain't cheap, but pack a lot of power in a small package.

Pat