Solar - can you check my logic?

[Cdash]

I have been studying solar and had all kind of great plans for an awesome solar system on my rig after I brought it home in February.

Here I am in June - kids got busy, work got busy, started camping = I got busy = solar plans haven't moved and we leave for 2 weeks in Glacier with no hookups 3 weeks from tomorrow.

All is not lost though. We have done Yellowstone, Rockies and Smokies without hookups in our old trailer with 2 marine batteries and a Yamaha 2400 and conservation, quite comfortably too.

I am planning to get 2 golf cart batteries tomorrow or Saturday to drop in our 29.5 BHDS HT. Was starting to think that we'd forgo solar this time around and just conserve and use our quiet genny during the allotted hours to keep the batteries in decent charge.

But then I got to thinking......

Its really a pain to worry about being at the rig during the limited generator hours. So I went to the Renogy website and Amazon.

I saw that I can get a Renogy 200w starter kit (negative ground) for $340 and free shipping. It comes with 2 100w Mono panels (or I can get with Poly a little cheaper), a 30 amp PWM controller that says it charges at 14.8 v in boost (which Handy Bob recommends if you believe in him), 20' cables, the combiner MC4 connectors, a tray cable and foot brackets. Only thing missing is a battery temperature sensor.

Here is what I am now thinking:
I am thinking that I can buy this starter kit, mount the controller right behind the battery compartment and use it as a portable kit (maybe hinge the panels to each other). Running numbers, I expect that this will keep our batteries pretty well topped off the whole time with some conservation.

I can add panels down the road, or likely sell the system if I go a different direction (voltage), or I can add panels, or maybe upgrade the controller. But either way, it seems too cheap and easy not to do it at this point as a leap into solar and a benefit for my upcoming trip.

Any reason why I shouldn't just go ahead and do it?

[klassic]

I'm doing it.
Waiting for parts to arrive and to go pick up the panel.

[Shilo7734]

Absolutely go for it... Renogy rocks... 100 Watt Solar Panels by Renogy - Camping And Fishing California

[justman]

No reason you can't do it... Also, you don't need to mount anything permanent right now if you don't want to. You can make a simple portable mount for your panel(s) and just run the cables to your charge controller, charge controller to batteries and you're set! Any power you get into the batteries from solar saves on fuel and noise. Sounds like a win/win to me!

[Seann45]

IF your going with a portable system MAKE SURE you can cable lock them to something so they don't disappear.. or the wind take them away...

[Cdash]

Well, I ordered it. I figured that for $340, I'll give it a go! I'll update when it gets here and I start setting it up.

[Shilo7734]

Ahhhh, you're gonna be loving life...(-;

[Cdash]

Here is what I ended up with. I didn't fuse my mc4 wires. I figure with using them as portable panels, I really don't need to. I am using the factory 30amp breaker that the roof solar connects to, in lieu of adding another one.

I got it wired up this evening and hooked up one panel. 8pm, Sun behind trees and I was making 0.4 amps. Will hook up both tomorrow and see how it does with high sun.

[klassic]

Did you measure that .4a by flipping your voltage moniter switch?

[Cdash]

Originally Posted by klassic

Did you measure that .4a by flipping your voltage moniter switch?

No. By a regular meter. Mosquitos were starting to come after me.

I'll test that out tomorrow.

[Cdash]

So i hooked up both panels this morning.

9:30 am, panels flat, 18.9 volts coming from the panels, 14.9 volts leaving controller, battery monitor reading 14.85 volts. I measured 15ish amps from the panels before my meter leads got hot. Guess that I should have noticed that it was a 10 amp max meter before I used it.

So as I was looking at my battery monitor, I noticed that I can hear the batteries bubbling. Thinking that it isn't right, is disconnected my panels. The noise stopped. Should I be getting a bubbling should from my batteries?

[klassic]

Sounds to me like it's in "equalize"
According to your units specs 14.8v is the equalize mantainance voltage and it happens every 28 days.
Maybe it starts on day one?

[Cdash]

That's what I was thinking.

The bubbling I heard in the batteries concerned me. I don't want to screw up $300+ in batteries......

I changed the controller setting for agm batteries and the bubbling was a whole lot less.

I need a better meter hand held meter.

[Cdash]

Originally Posted by klassic

Sounds to me like it's in "equalize"
According to your units specs 14.8v is the equalize mantainance voltage and it happens every 28 days.
Maybe it starts on day one?

Actually, looking again, 14.8 volts is boost voltage for flooded batteries. Equalization shows 15.4 in the manual.

Anyone else notice bubbling in the batteries during boost charging? Anything to worry about?

[Dustdevil]

OK. I'll bite. Watching this thread because I'm just intelligent enough to learn by watching others. I'm not one of those who has to pee on the electrified fence for myself to figure things out, LOL!

[klassic]

My Morningstar mppt is equalizing right now and the Trojans are bubbling away at 15.2v

When I was hooked to a smart charger during the winter it kept charging at 14.8 for days and the batteries were bubbling the whole time
It never went down from 14.8 and they never stopped bubbling. So I disposed of it.

[klassic]

The charge controller is finished equalizing and voltage is now 14.35 and they are still bubbling. So I guess your ok Cdash.

I don't understand though why it would equalize for over an hour and then drop back to absorption.
The batteries have been bubbling for most of the day.

[jasum]

I hope you get it all figured out klassic!
Then you can let all of us know what we need to do. I know nothing about solar, but am very interested in it.
Keep up the good work!

Jack

[Murphie]

I like your thinking. I too spent considerable time planning a solar install for our trailer. We recently got back home after a two month holiday in California. The campgrounds all had power but I kept track of the times our trailer would have benifited from solar had there been no power. Most of the time the trailer roof was partially covered by tree shade. This has made me think that even at state or provincial parks how many times will you be able to benifit from a system installed on your roof. I think your idea of being able to place a couple of panels out in the sun and having a small generator for back up is the best solution.

[klassic]

I think you're right Murphie. A small generator for back up would be a benefit with low to medium solar setups.