Newbie build small portable solar setup

[mattro]

Finally have the money and batteries to do my first build.
The main purpose is of the project is provide some power during car camping. Led lights, charge electronics, etc. Also to provide some power in a 'lights out crap hits the fan situation'. The other goal is to learn so in the future I can get major portions of my house over to solar. The unit will not be used daily. I am in a rental in not very good neighborhood so I dont want to leave panel outside when not in use for now.

Due to my job, I have available to me true deep cycle 70ah telco batteries.

I am thinking of putting two of these batteries in a mobile enclosure, and have dc plugs, meter, etc mounted on walls of enclosure.

My first panel will be a 100w mono panel.

A couple questions:

1. For the controller, I am drooling over a 40a Tracer MPPT at $190 but really cant justify expense now.Tracer seems a decent brand although customer service seems to be lacking. They have a 30a one for $154, and a 20a for $80. I can swing the $80 but being maxed a 2 panels sucks. With such a small system and infrequent use should i just go with PWM controller for now and upgrade when I grow the system and have more budget? What starter PWM controller, or starter MPPT would you guys recommend?

2. Panels: Is there much advantage to buying two 50w panels and wire in series as opposed to one 100w panel at 12v? Voltage drop, wire size, etc. The single panel is cheaper. Can starter PWM controllers take two 12v panels wired in series going to a 12v battery bank.

[SunEagle]

Usually 2 smaller wattage panels (ie 50w) will cost more than a single 100w panel. The same is true for 2 x 100w panels compared to a single 200w panel.

If you decide to keep you system around 200 watt total then a PWM CC is ok. Once you start increasing the total panel wattage you will find that even though a MPPT CC is more expensive up front it, your system will be lower in cost using it and gird tie (>200w) panels.

You really should first determine how many watt hours you will need for each day. Then size your battery system, panel wattage, charge controller and inverter. In that order. Getting a charge controller and panels first usually ends up with the wrong or undersized equipment.

Also usually a "telco" battery is not really rated as a "deep cycle" or daily use battery. Most are designed for UPS application which means they can be discharged "deep" a few times but normally just stay at float voltage and ready for a power failure.

[mattro]

Thanks for taking time for reply. Gets frustrating seeing tons of views and no replies. Chose this forum cause it looked like people were willing to help more then other forums.

Do you have any hesitancy buying poly panels vs mono panels?

[SunEagle]

Thanks for taking time for reply. Gets frustrating seeing tons of views and no replies. Chose this forum cause it looked like people were willing to help more then other forums.

Do you have any hesitancy buying poly panels vs mono panels?

I have no issue with purchasing poly crystalline panels as long as the cost is less then a mono panel of equal wattage and grade.

Poly actually has some advantages over mono where they can generate in lower light conditions but usually their efficiency is lower than a mono type panel so they might not generate as much kWh during the same time frame.