With winter coming on, plenty of boondockers are heading south to the warmer climes. Solar power is definitely riding high on the list of questions that folks have. But even if you have a whole "farm" of solar panels on your roof, you've still got to have someplace to bank that power. A big "whatif" is this one: What if there's no more room in my battery compartment for more batteries?
Yes, Virginia, you really can stick more batteries in your RV. It's best to keep the add-on battery as close to the originals as possible, or else relocate all of them to the "new" location. Why come? Well, the longer the run of wire to the battery the more the power loss. The battery or batteries closest to the power source--your solar panels for example--will get a better charge. Some suggest that if you can't get them all together, then you could conceivably "rotate" them from position to position. Making sure they get fully charged is really important, because this will prevent sulfation, a killer of batteries.
In any event, you should always do your best to use the same make and manufacture of batteries, and ideally they should all be replaced or installed at the same time. Why so? Older batteries will have less life in them, and will "take the new guys out." Batteries wired in parallel want to "see" the same voltage between them. The higher voltage battery will "lend" juice to the lower voltage battery, pretty soon, everybody suffers.
In putting together an alternative battery location, be sure there's no chance for hydrogen gas (a byproduct of charging a "flooded" lead acid battery) to get into your coach interior. The compartment should be vented to the outside world. Some worry that the battery gassing will corrode the inside of the compartment--they suggest painting or somehow coating the inside of the compartment to prevent this. Well----we've added batteries in other compartments and never experienced any corrosion issues--of course, we made sure there was good ventilation.
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