New to Solar, where to get started or should I get started ?

[3404]

I have been reading posts on this site about 12 volt Solar and now wonder if I should try solar or not bother.
What I have is a car trailer with a flooded 27DCM sized deep cycle battery (200 min is all I could find on the battery), I use 12 volts for the jack on the trailer and also for a weather station and radio I usually run all day at the track. I almost always have available 120volt power I can plug into and I also usually keep my trailer plugged in at home while it is parked, hence should I even bother with solar?
Why I want to try solar is I only keep a trickle charger 1.5 amp plugged in and hooked up to the battery all the time and thought a solar panel and charge controller might be nice to keep the battery full or closer to full..
Also if solar would be worth adding can I leave the trickle charger on while the solar panel is charging?

Thanks in advance for any input.

[gmanInPA]

Would you ONLY want to replace the battery's self-discharge rate with solar, or would you want to charge while using, rapidly charge the battery, etc?

OAN: The battery you mention appears to be a starting battery, despite being a marine battery. The measurement of CCA is the give-away. You might consider getting a storage battery - one that is measured in Amp Hours (AH).

[gmanInPA]

You might find some good info here: https://www.solarpaneltalk.com/forum...ger-controller

[gmanInPA]

If you want to only overcome the self discharge rate, there are a few steps to figure things out...

1) Know the size of the battery (in amp hours) Ex, 100 AH
2) Know the percentage of charge lost per month Ex. 30%
3) Multiply the battery amp hours by the percentage lost per month, then divide by 30 (avg days per month). Ex. 100 x .3/30 = 1 AH.
4) The prior step is the AH lost per day. You need to now figure out how to get at least that much charge back into it...
5) Determine the number of full sun hours where you're likely to be.. Ex. 5.5
6) Divide your AH lost by the avg full sun hours. Ex 1/5.5 = .18A (180mA).
7) In this example I just outlined, A panel that produced at least 180mA would be the minimum size necessary.

That being said, going a touch bigger might be necessary depending on how many consecutive cloudy days you have, etc. You might also want to use a blocking diode to prevent the panel from draining your battery when not charging.

[3404]

Thanks for the info so far, I would like to try to keep up with the battery while I am using it as well as maintain the battery when not in use.
I will see if I can figure out what my weather station uses while it is running.
I am sure the trickle charger running on it does about next to nothing while I am using 12 volts.
If I was to get a charge controller to start could I run my battery to it and hook my 12 volt load to it to see what I am using ? I know that would be putting the cart before the horse but..?

I was hoping experimenting with my trailer and figuring out how Solar charging works I could maybe do something with my motorhome next.

Thanks

[3404]

You might find some good info here: https://www.solarpaneltalk.com/forum...ger-controller

Thanks that helps, guess I better get me a Temp Compensated Battery Hydrometer as well.

[gmanInPA]

If it were me, I'd probably just go out and purchase a 12v trickle charger that I knew was going to be producing decent charge current. You said you found the comment '200 min' on the battery. I have seen mention that such numbers are the number of minutes the battery will maintain a constant 25A load at 80º F until voltage drops to 1.75 volts per cell. The same mentioned that to get an approximate AH rating, multiply that number by .6. 200 x .6 would be 120. Thinking on this though... that seems rather high for a deep cycle marine battery to be close to 120 AH capacity. I don't think a true comparison can be made between them and will ultimately be mostly a guess.

Disclaimer: I have not verified this, but seen mention of it in some ham material - I don't know that I believe it myself since it's an apples to oranges comparison. Nevertheless, It might at least serve as a baseline to get you headed toward the a charger that is suitable.