Rubicon Solar Power Experience (1 Viewer)

[Semi Hex]

I've been using one HF panel until this year when I went to three (busted the old one). It seems to work just fine. I went from one light to eight with a water pump and charging station for my iPads and phone. I don't go in for the refer foolishness.

 

[Cruiserdrew]

HaHa, "refer foolishness". I can promise one day in the future you will get a "refer" and it will be a full on Homer Simpson DOH! moment.

But glad your system is working for you. Good job with the power meter and power poles.

 

[Semi Hex]

I have no place for a refer in the future. They will have to be far more efficient than they are today. We will see!

After talking to you about powerpoles, I went whole hog into them, I can test most of my usage by fixture, whether water pump, lights, iPad charging or whatnot.
I now know it takes 4.22 amp hours to charge our iPads and iPhones from 50% or our 2 Goal Zero light of life (?) led's don't use half the power the company says they do.

Yes, my setup uses power just by being switched on but the extra stuff makes our camping trips so much nicer.

 

[Enigma]

Earlier in this thread it was mentioned a couple times that the charge controller should be near the batteries, why?
I'm looking at upgrading/adding/replacing my current 50 watt panel and the cheapo PWM controller to something larger like a 100 watt unit with a MPPT (and probably one of those digital displays as well), as the 50 is just not large enough to keep things going on a longer term basis.
My current setup has the controller in the back of my 80, mounted right by the sub speaker, and then extension leads from there to the panel. I have heavy duty double insulated 6 gauge marine wire running from my accessory battery to a distribution block mounted inside the rear quarter panel that splits to the charge controller and to a 1500watt inverter mounted in what used to the little storage compartment on the other side of the sub speaker. The puma (since removed as it seized) was wired through the charge controller.

 

[Cruiserdrew]

You want the CC to be near the batteries, because the voltage drop between the controller and battery will slow charging somewhat. Also, many charge controllers, are temperature compensated (desirable), and so you want the controller in the same compartment with the battery.

100 watts will not need an MPPT controller unless you just want it.

I would recommend you turn off the inverter unless absolutely needed (Looks like that's the switch function?), and upgrade your charge controller to something a bit better and keep that one as a spare.

I really like these panels-very good price for a 160 watt panel (which will be right about 10 amps at full output).

1- 160 Watt 12 Volt Battery Charger Solar Panel Off Grid RV Boat 160 watt total

 

[Enigma]

Wow, that is a great price on that panel. And yeah the inverter is always off, that switch is a remote power for it.

I was thinking MPPT mainly to maximize the power, as we don't get "the same" sun as you Californians.

 

[Cruiserdrew]

No question an MPPT will be a bit more efficient, but you'd be better off with a bigger panel. Now if you go to higher open circuit panels, then for sure you'll want to run an MPPT controller.

The ebay panel I listed and the Morningstar SS10 works great. That's what I'll be running at Rubithon this year, but it's running in my driveway right now.

 

[e9999]

If I read the data sheet on that 160W panel correctly, they did the test at 1deg C. That would be highly misleading. Standard test conditions are 25C and even that is also rather misleading given the normal operating temps of the panels in the sun. So if that 1C bit is true, one might expect considerably less than 160W in the real world. And this seems incompatible with the 160 figure listed on the nominal spec sheet at 25C. Something seems off here. But nice to see some data provided for a change. Andy, do you have your own numbers for it?

(Why is this thread in the Comm forum now?)

 

[Cruiserdrew]

Yes, I have about what I expected. All panels are rated in "standard conditions" which are defined parameters when they flash the panels to establish the rating. These panels unlike most actually come with the flash report. I'm sure you know that panels are much more efficient when they are cool, which is why you want a bit of an airspace under the panel in all cases.

The best I've seen in crude testing is 9.7 amps @ 14 volts. That was about a 90 degree day So that's 130 watts delivered to the battery. Very consistent performance to what I've seen with other panels. I can live with that.

My 100 watt panel I've seen 5.7 amps @ 14 volts, so that's 80 watts into the battery. Again, not bad.

Did you ever build a system Eric? Maybe you could move this back to a more appropriate forum. It's strange someone would move it.

 

[e9999]

Unfortunately, all ratings for panels are inherently optimistic for most real world use because of the 25C test condition. But if they give you the temp compensation factor -as they should- you can correct the nominal power figure for normal high temp use estimates. Will still depend on insolation though.

Isn't the Comm forum a new one? Somebody must have moved threads en masse. Maybe this is intended to be all power related stuff too.
But since it's your thread I'll move it to whereever you want. What is your pleasure?

 

[Cruiserdrew]

Probably Camping gear

Maybe the electronic toys forum was renamed?

 

[surfpig]

Probably Camping gear

Maybe the electronic toys forum was renamed?

That's what happened. Which is funny, as this thread doesn't belong in here now.

 

[e9999]

yup, right, was Electronic Toys or something like that. Was this thread there before?
New name seems a bit narrower.

Anyway, moved to Camping gear...

 

[Semi Hex]

I was outside of Sacramento on a very warm weekend and I topped out at 5.1 amp hours peak on the best of five days with my 100 watt Renogy panel. I was really thrilled to be able to recharge my system in under three hours! (it was 103F that day). Of course, our biggest usage is recharging our iPads and phones, since the seven led lights hardly use anything.

Most usage in one day was 11.54 amp hours, some of it was just the system being on.

 

[e9999]

FWIW, it is best to talk about Wh or related true energy units when talking about energy production, because an Ah figure needs to have also the voltage known for it to make sense in that context.

 

[Cruiserdrew]

FWIW, it is best to talk about Wh or related true energy units when talking about energy production, because an Ah figure needs to have also the voltage known for it to make sense in that context.

From a science or engineering standpoint this is true. However, from a practical man-in-the-campsite standpoint, it is much easier to think and work with "12 volt" batteries in AMP HOURS. It's easy to measure voltage, amperage, and time, not so easy to measure watts, so you would need to end up calculating watts anyway, which ignores the unintended losses and inefficiencies.

Seriously, Eric, you're an engineer-build a solar system for fun. Don't sweat the details, just make one that works, and I think you'll agree and you'll be impressed with what it brings to your camping experience/capability.

BTW-for the uninitiated, 12 volts is in quotes because a normal battery would be nearly discharged at 12.0 volts, operates most of it's life underway at 14.0 volts, and rests at 12.6-12.8 volts depending on the exact chemistry. A solar system's charge controller will typically try to raise the voltage to around 14.5 volts and hold it there while the battery absorbs a full charge. Once full, it will drop the battery voltage to 13.5 volts or so and hold it there until loads or darkness draw it down. Then it starts the cycle over again.

 

[Semi Hex]

It's no problem, I didn't know what the standard was. I will do better next time!
What really matters, is I have all of my toys working and my system recharges itself very quickly.

 

[e9999]

Right, if you never run out of juice, you're golden regardless of what the technonerds blabber about.
Which prompts me to add that with a charge controller, you would also need to know whether it's Ah on the battery side or the panels side to calculate energy and that with the corresponding voltage.
Anyway, I have an inexpensive little DC meter that measures directly in Wh. Max min instantaneous etc V, A, Ah, Wh, hours, all for like $30 IIRC. Fun!

 

[Enigma]

Where has everyone located the charge controllers in their vehicles, right in the engine bay? Pictures (80's preferably ) worth a thousand words.

 

[Cruiserdrew]

As close to the battery as possible.