If you have a solar power array and you are wanting to use that to charge a bank of batteries the most efficient method is to wire them in a series or parallel setup.
This is actually a very simple thing to do but people often get confused by the net output of the battery bank. If you were wanting to use two 12 volt deep cycle batteries you would end up having the equivalent of one 24 volt battery. The effects of wiring a battery system like this is that the voltages are cumulative. So if you were to have 4 batteries then you'd end up with 48 volts and so on.
Where people get confused is with the amperage. No matter how many batteries of the same voltage you wire in series or parallel the amperage remains consistent. So if your batteries are 220 amps and you had four of them, you'd still have a battery system that generates 220 amps, just with more volts.
When wiring a system like this you attach the negative feed from your solar array to the negative post on the first battery. Then wire the positive post on that battery to the negative post on the next battery. If you have a 2 battery system then the positive post on that battery would go to the positive lead on the solar array.
Remembering this is easy, it's plus to minus for as many batteries as you want, the open posts on each battery then go to your solar array.
By using many batteries wired in this manner you will get the benefit of having additional energy storage for your solaried system. Your controller will ensure that your batteries do not get over charged.
Remember that when wiring in a series or parallel system you will need to have enough solar panels in your array to keep that many batteries charged and also that all of your solar components are able to handle the voltage that your batteries is capable of producing.
When wiring batteries be careful not to wire them incorrectly as it could lead to a short, a electical shock or even fire and some cases even an exploded battery. Safety is very important when working with high voltage battery arrays.
If you have questions on this please consult with a solar expert in your area they are there to help and will most likely take the time to work with you on setting up your battery systems.