RoyB wrote:
With the smaller SOLAR PANELS I would think only in the term of getting my batteries topped off. A typical 100WATT SOLAR PANEL will only give you around 5AMPS OF DC current when in high sun. Two Panels will make this 10AMPS of DC CURRENT.
This is great if your trailer is sitting in the sun for several hours and will slowly bring up your batteries to full charge over time.
All batteries have the same charge rate depending on the DC VOLTAGE and amount of available DC CURRENT for them to use.
A typical 12VDC deep cycle battery will want to see around 14.4VDC with around 17-20AMPS OF DC CURRENT available to use if you want to bring this battery up from its 50% charge state to its 90% charge state. This will take around three hours of charge time for me with my setup. If you have multiple batteries in the setup then you will want to have 17-20AMPS OF DC CURRENT available for each battery. i.e. your two batteries will want to see a total of 34-40AMPS DC current if you expect them to be charged in THREE HOURS TIME doing the 50% to 90% charge rate.
As you can see the two 100WATT Solar Panels will not do this for you in the three hour window. It will take much longer to get them charged back up. Then you will fall into the high sun going away after 6-7 hours depending where you live. Of course after dark you will not get any charge coming from the solar panels.
Just passing all this along to get you thinking what you will be doing with your two 100WATT SOLAR PANELS. If you never drop your two batteries down much with using them the two 100WATT PANELS will bring them back up real nice...
I would experiment with your solar setup sitting at home for a couple of days so you will know what to expect using the things you want to have on running off the batteries. Most of us just have the trailer lights and the home entertainment items going between 6PM and 11PM.
The idea with batteries is to never drop them below the 50% charge state or around 12.0VDC without re-charging right away. Going below the 12.0VDC charge level will start doing damage to your battery. Your batteries will last a long time following this simple rule...
Just some of my thoughts here. I have been living off my 255AH battery banks for several years camping off the power grid. I am just now starting to think SOLAR PANELS to supplement my 2KW Generator charging of the batteries.
Roy Ken
Thanks for the input! I plan to simply top off my batteries during the day.
The Solar suitcase I have is 100w total(2 50w panels).
I don't want to be limited to Full hook up sites, and since I have electric awning, electric stablizer jacks, and electric hitch jack, I want to have enough juice in the batteries to hook up and go home after 3-4 days of camping.
I don't plan on using a lot of electricity(lights(about half are LED), cpap, detectors, water pump).
This was my first step into solar to see how it will work.