This Solar Thing is Quite Exciting!

WYOFamily

New Member
Good choice. I've been happy with my SOK batteries.

A few things to keep in mind with the batteries. They have a rated max continuous discharge of 100A. If you put the two batteries in series you have 24V with 100A max discharge (2400W). If you put them in parallel you have 12V with 200A max discharge (2400W). Either way you want to keep your inverter below 2400W to avoid asking the batteries for more amps than the rated max continuous.

If you put the batteries in series for 24V you will want to first wire them together in parallel. Then connect a 12V LiFePO4 friendly battery charger. Put the positive lead on one battery and the negative lead on the other. Charge the batteries to 100% SOC. Once charged you can disconnect the charger but keep the batteries connected in parallel overnight so they stay at the same SOC. After that you can set them up in series as needed. At first I simply fully charged each of my two batteries one at a time and then put them in series. I then had some issues when they were being charged in my system. The two batteries got way out of balance when very close to 100%. Once I performed the steps I just outlined they have been working together very well. I doubt this is specific to SOK batteries. Those steps should be done with any batteries that will be put in series.
Wow, great information. is there a battery charger that is reliable, has the features, and is too expensive tat you would recommend?

BTW, how’s the off grid living treating you?
 

rmaddy

Solar Addict
I used the Victron Energy Blue Smart IP67 12V 17A charger. It's $133. They have other variants with different amperages.

Living in the trailer has been great so far. I've been in the SW Colorado mountains the last 5 days. The aspens are looking great right now.
 

WYOFamily

New Member
I used the Victron Energy Blue Smart IP67 12V 17A charger. It's $133. They have other variants with different amperages.

Living in the trailer has been great so far. I've been in the SW Colorado mountains the last 5 days. The aspens are looking great right now.
I think I’ll get the same one. Thanks. Too bad it won’t do 24v also.
 

rmaddy

Solar Addict
They do have 24V versions but not one that does both 12 and 24V. But the only time you'll need this charger is to rebalance the batteries maybe once a year. Otherwise your 24V setup will be charged by solar and by your system charger (perhaps an inverter/charger or a stand-alone charger) connected to shore power.
 

WYOFamily

New Member
Perfect! I will get one on order. Batteries arrive tomorrow.
As far as panels go, is there any brand you would recommend or recommend against? I’ve been leaning towards Rich Solar 200w 24v. Need to figure out SCC size from there.

still haven’t really had much time to put this system together in my head. My trailer is bare bones at the moment so I don’t know what my demand will be yet.
I think 800w will be my starting point. This is all pretty new but the possibilities are amazing.
 

rmaddy

Solar Addict
Before you think about specific panels you should work out how much solar you will really need based on a proper energy audit. Then work out the physical limitations of what will fit on your trailer. Take into account roof fans, vents, and anything else on the roof.

From that criteria you can narrow down how many panels and what wattage. Then I would look for panels with thicker frames and the highest load values you can find. This will help the panels survive being on the roof of a trailer. Also look for local dealers near you. Getting panels shipped is expensive. If you can find a local dealer within a couple of hours from you then it may be a lot cheaper to go pick them up. So that may narrow down your search based on what they have in stock.

That's what I did. I knew I wanted 3 panels in the 300-350W range because that met my power needs and those were the biggest that would physically fit. I got a list of specific models from my local dealer and then I made a spreadsheet with all of the relevant specs including frame thickness, width, and height, as well as load rating. In my case a panel width difference of 1/4" could be the difference between the panels fitting or not. Hopefully you have more room than I did.
 

WYOFamily

New Member
I used the Victron Energy Blue Smart IP67 12V 17A charger. It's $133. They have other variants with different amperages.

Living in the trailer has been great so far. I've been in the SW Colorado mountains the last 5 days. The aspens are looking great right now.
Just wanted to let you know, I took your advice with the charger. I purchased the IP67 17A. Thanks for the suggestion. I haven’t balanced the batteries yet but we’re getting closer.
 
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ianganderton

Covid free in NZ
Solar panels are one of the best bang for Buck components. General rule of thumb is fit as much as you can fit in the space you have.

Brand doesn’t make a huge difference

It’s best to have each array made up of the same matched panels. It’s a bit awkward to add to them with different spec panels further down the road.

The thing to understand is winter pv generation. Solar obviously requires the sun. In the winter there is typically less. This can be calculated so is easy to understamd

What’s the worst case scenario solar wise you are planning for your trailer?
 
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