Newbie to solar question

[Majja13]

I am thinking about building a some what protable solar recharge kit for my tt so I can do up to a week of boon docking. I know I need to do the total power worksheets. What I was wondeing is more or less which Charge controller to look at. I want to use 1 200 W pannel to start out with. I currently have all LED's for lights and at this time no TV or DVD's, but will be getting one in the future. Battery wise I have to GC2's. I do not have a gen set. I wanted to try and keep the cost down some what on this as to not spend as much as a generator would cost me. What are som of the brands to look for? Is a 25 or 30 amp controller also the ideal?

I willbe camping above 8000 ft most of the time and I french press my coffee.
Thanks
Matt

[pianotuna]

Hi,


Here is a simple flow chart.

Budget-->Energy Audit-->Battery bank size-->number of watts-->PWM or MPPT.

Here is a link to the rather special spreadsheet that N8GS has created to help size solar battery charging systems!
Solar Spread Sheet N8GS

[KD4UPL]

A cheap (poor) charge controller can cause lots of problems. It's not the place to skimp. You want one that has programmable charging set points so you can charge your batteries to the manufacturer's specifications. A poor controller can overcharge or undercharge your batteries. Also, an MPPT controller will allow your panels full output to be better utilized than with a PWM controller. If you're going with a larger (less expensive watt/dollar) panel it will likely have a high enough Vmp that you will need a MPPT controller anyway.
RV usage, I guess because of price, is one of the last places PWM controllers are installed anymore. The home, cabin, grid tied solar industry has almost completely moved to MPPT controllers for all of their advantages.
I would highly recommend Blue Sky charge controllers.

[RJsfishin]

Those big house panels are cheaper $ per watt, but for portable use, they are big and heavy.
I elected to go w/ 2 smaller lighter, easier to store panels And a $10 15 amp controller works fine w/ them too..

[Majja13]

That I will deffently do.

[time2roll]

If you want to use a low cost PWM controller then look only at 12v panels.
12 volts is nominal. Actual voltage will be 17 to 22. Controller cuts voltage to charge properly.

This type of system you want to compare Isc or Imp for choosing a panel.
Isc = Amps at short circuit
Imp = Amps at max power

Post a link to the items before you spend money.

[HiTech]

Agreed. I did a lot of research on both my batteries and panels, and still have not actually mounted anything to the RV. I am still using what I have at the house instead. You certainly can rush in, but requirements change with experience.

Jim

[Majja13]

I have not picked a specific pannel yet, that is just a ball park. I am in the information gather phase. I am trying to learn as much as I can soak up, I think this is a very interesting subject to be honest.

[time2roll]

Do you have a link to that 200w panel?

[HiTech]

There are some very inexpensive Chinese solar controllers on eBay you can start with, depending on what batteries you have.

Be slightly careful. A high altitude you may get ABOVE the peak amp rating for the panel, requiring a slightly larger controller. 8000 feet give you a bonus in solar output when the sun is aimed right at the panel.

Jim

[JiminDenver]

What is the VOC of your panel. I am assuming above 24v meaning you may need a MPPT controller.

I use this one on a 230W panel clicky

Here is the thread I started on it.

clicky

It is less expensive and has fewer high end features but does the basic job well for half the cost of the next step up controller.

If you keep the panel/s to a 12v panel you can use a much less expensive PWM controller.