I'm looking to keep my RV battery charged in the winter what is the best way to make sure this is done? It faces south so I was thinking of some type of solar system  the battery is a car battery. Thanks!

I did not have much luck with the cigarette lighter plug in solar chargers, FWIW.
There may be improved models out there now and hopefully someone will chime in.
If your inverter/charger in the RV is fairly new it should be a "smart" charger and won't overcharge or otherwise damage the battery. If you don't know about the on board unit I have had good luck with the Deltron Brand Battery Tender. You'll have to run a 110v cord out to the RV but the Battery Tender will do the job. I have 3 blue Optimas in a boat and have three tenders on it all winter. 3 years now and no complaints.

http://www.batterytender.com/

you can get a electric fence solar battery charger.....they work and have a decent charge controller on them.

run a cord and get a small maintainer......$0.02...

I plan to do a topic on battery equalization for Dummy's [like me] soon.

Simply charging the batteries may not be enough to preserve your batteries -as I have learned the hard and $$$ way.

I think it important to do an 'equalization' process and the usage of the word 'equalization' is sort of a misnomer and really had me confused for years until I actually started doing it for the last year with some large battery banks and I think finally understand what it's all about.

Google -of course- has nearly unlimited info on the subject but there are really some concepts that are missing in the explainations. At least to my poor brain...

A practical understanding of 'equalization' is important if you use flooded batteries.

I installed a marine grade batter disconnect switch.  When I have it in storage I turn the switch (actually a removable key) and it disconnects everything in the camper )CO sensor, clocks, etc) so nothing drains.  Granted there is only one or two months at most I don't use my camper (nice winters in TN) but it never seems to loose charge.

HomeDepot has the solar battery tenders on sale and Lowe's had two choices of solar battery chargers at their stores in the area.

i have a batt disconnect on 3 AGM batts. i put the charger on it once a month just to make sure(in fact did it yesterday), but they are always fully charged.
but a 1.5 amp maintainer is good to have. otherwise one ov the solar ones would work great too. then you wouldnt have to worry about checking it.

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2 amp charger/maintainer from Sears.

They cost under $20 when I got mine.

that

Yup, that. I use one on my motorcycle and one on my solar battery when I don't have the panel connected.

Just clip the alligator clamps on the battery terminals, gently close the hood and run an extension cord out to the RV and forget about it.

EXPY37, i agree with you, there is a huge lack of understanding on the "equalization" process and what it entails.

I look forward to your article on this process.  I have found many write ups online, but they don't seem to work for my situation.

Thanks for putting the info together.

That's the model I have.  So, when the light turns green, I don't have to disconnect?

Nope, it's an intelligent charger. Once the battery is full it switches to trickle charge mode, which keeps the battery topped off with a very low current. This will not damage the battery (in fact, it's the best way to extend the life of it).

Make sure you keep a good eye on the water levels.

How does the charger know when the battery is 'full'?

http://www.batteryminders.com/batterycharger/catalog/BatteryMINDer-Plus-12-Volt-133-Amp-Charger-Maintainer-Conditio-p-16134.html

Works on autos and tractors, would presume it will work on an RV.  Is safe to leave connected for long periods of time.  Have read reports of bad experiences with the batterytender brand ones but haven't used them myself.

It measures the voltage across the battery. When the battery is charging, the voltage the battery puts out increases, but when it's fully charged it decreases slightly. So periodically the charger switches from charging the battery to reading its voltage and keeps track. When the voltage across the battery decreases, the battery is full so it switches to trickle charing mode.

Expy, it is my understanding the smart chargers know it is "full" when resistance to current reaches a level predetermined by the programming, and the battery's voltage to indicate the charge is complete. High resistance/low voltage will trigger the problem light.
I don't use flooded batteries, in my vehicles, but your point is well taken regarding them.
There is a product called an isolater/combiner sold by www.hellroaring.com, that is a trick little deal. It allows you you have multiple batteries and "hide" one of them.
For example, in my boat I have two Optima blue tops that are the primary units for the boat. They are wired together for 12v, and the alternator and I/C see them as one.
The alternator charges them as one. With the I/C I have a toggle swtich. In the off position, the I/C is not functioning, the alternator sees only the primary batts.
In the "on" position, the two primary batteries are charged up, then when the I/C sees a full charge, it directs the charging current to a spare battery, isolated from the load. Once that battery is charged, the I/C floats a charge on all three. There is a momentary position on the switch as well. In this case, if I draw the two primary batteries down too far to crank the engine, I push the switch up and it combines the 3rd battery, bringing it's full charge on line to start the engine. Once fired up I return the switch to on and the system will go through the charging process as previously described. This thing is great, and saves the alternator from being fried by trying to charge 3 flat batteries all at once. It never sees the spare until the other two are charged.
In the winter I disconnect the three from the system and put the Tenders on them. I check them every couple of months with a voltmeter and they come up to around 13.7 and stay there.

battery tenders are great.  I have them on my motorcycles and atv