Hello all new to us I have 2 x 97 amp batteries on our caravan and would like to run a solar panel to them what size panel would I need to keep them charged , from where the panel is going to be to the battery is roughly 30ft and the controller will be 12 ft from the panel , and what size wire to run from the controller to the batteries roughly 18ft as all we would be running will be lights ,engel 38lt, tv ,stereo ,water pump but the main thing is what size panel to suit the batteries to keep them charged thanks
The answer is not so simple as you hoped. So I will answer with some more questions and a suggestion or two
How do you charge them now ? How many amp hours do you use every day ? Why are the distances for the wires so long ? Do you know anything about wiring and DC electricity ?
The suggestions: search this forum by just brousing the threads or by using the search function up in the top blue bar.
Second suggestion is to look for a suitable book about the subject in a library or shop. I have one by Collyn Rivers who has written a few on the subject.
Charles, you did not answer Jaahn's questions when you were on the forum a few minutes back.
I too am a little surprised with the distance between the controller and the battery. Over a distance like that you are going to get a small voltage drop between the controller and the battery, this will effect the charge rate of the system and you may need a significantly larger panel. There are however some controllers that have input terminals so you can connect voltage sense wires between your battery and these terminals. If you use these the controller will supply an increased voltage output and then the battery will be getting the correct input voltage.
My rule of thumb is to install a 120 Ws of panel per 100Ah of battery if you are up north. Increase to 150 Ws per 100 Ah if you are in Victoria or even more for Tasmania.
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PeterD Nissan Navara D23 diesel auto, Spaceland pop-top Retired radio and electronics technician. NSW Central Coast.
