Solar controller question

Horizon170 wrote:
Just curious as I don't have any solar-----will this 100 watt kit keep two gp 27 batteries topped off?

How long is a length of string? :) It depends on how far down you get the batts in a day and how long the solar has to recharge them that day.

I find in summer that 200w of solar is enough to keep four batts going while camping, so 100w ought to be enough for two batts. But we use more than two batts worth, so that would not work for us, we need four batts solar or not.

In cloudier times or shorter days, it is not enough. But then you can do a shot of charging with the generator powering a charger and then let solar do the rest of the recharge if there is any sunlight that day

For when not camping, just to keep the batteries from going down, it is more than enough

~DJ~ wrote:
I just bought a 100 watt RV solar kit from Amazon made by
Renogy. It has a 30 amp controller but all that came with it as far as instructions is a quick start guide which ,in places, says to see the manual.

Problem is no manual came in the box.

It shows how to hook it up and which colored flashing light means what but I see no way to adjust anything. It says it is safe for an AGM battery but it is my understanding you have to set a controller to match AGM charge rates.

Is it all preset? Should I trust it or buy a decent controller that has these capabilities?

Thanks .....DJ

Here is what I saw in my instructions today..

Hook up panel so it's making power from the sun and connect to your battery.

Hold that set button down for about 15 to 30 seconds until you see b2. b2 is the default value for VRLA or "Valve Regulated Lead Acid" batteries, otherwise know as gel cell.

Once "b2" shows, release and press the button again quickly and it will now show b3. b3 is for AGM battery charging. Let the charge controller sit for 30 seconds, and the light should go out and it will remember that setting, for AGM batteries. b1, for future reference, is for open vented, regular old Lead acid batteries like most of us use.

For your charge controller to have this feature, it should be v1.2 If you have v1.1, well, then, I can't say for certain.

Horizon170 wrote:
Just curious as I don't have any solar-----will this 100 watt kit keep two gp 27 batteries topped off?

Depends, on a lot of variables. But in general, no. You need, at a minimum about a watt of solar panel per amp hour of battery. Since a group 27 is about 100-110 amp hours, and you have 2 group 27 batteries, you need, at a minimum, enough panels to yield 200-240 watts. And that would be in summer time camping, with longer days, and longer charging periods. You might need 360 to 480 watts in winter, if your solar panels are not aimed directly at the sun, and are instead roof mounted on your RV. Much less efficient with low sun angle. Far more efficient if you can put them on a portable mount and chase the sun with them by aiming directly at the sun for full power capture and output. Fixed mounting isn't always best. Sometimes portable yields much more than you think.

Just curious as I don't have any solar-----will this 100 watt kit keep two gp 27 batteries topped off?

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DJ, this is not a matter that can be decided by voting. They are your batts. Besides, I don't see anybody but BFL13 suggesting to keep this controller and use with AGM as is.

Keep in mind that BFL, even before he went from $20 controllers to $100-something, have been keeping an eye on his batts real good, with $240 battery monitor. When you not only can't change how batteries are charging, but also don't see how they are doing it - well, they are your batts in the end.

Thanks so much everyone!!!

The "yeahs" outnumber the "nays" so I'm going to use the controller provided. Plus I save $150. :C

Considering the cost of AGM batts (and ever increasing cost of any big batts due to growing deficit of raw materials), it pays treating them well. Which means - getting a proper controller with adjustable settings and remote temp comp.

Renogy 30 amp controller, adjustable?

PDF for renogy controller

Always check the website of the manufacturer of your product.

IF YOUR Controller is labeled CCM-2, you have the advanced, newer version charge controller that is programable for voltage and type of battery it can charge.

The "2" designates second generation, which has more programming features.

directions?

Is this the kit you bought? With the same controller?

http://www.rakuten.com/prod/renogy-poly-basic-solar-panel-kit-100w-poly-solar-panel-10amp-charge/255569641.html?listingId=306907483


If so, it's plug and play. It is set for 14.4V charging. You may be able to get the instructions on line for that controller from WENTEK or who evers rebranded name is on the outside of the controller.