Electrical batteries are used for storing electricity. The electrical system must be properly designed, cared for and used.
Batteries need kept cool (but not frozen), shade from sun (prevent UV light from breaking down container), kept charged (discharged batteries deteriorate more quickly), watered (distilled water to keep a charged battery's plates covered in water), properly charged (lower currents over longer periods of time are better), balanced (each cell properly charged, not over charged (will break down battery), ventilated to prevent buildup of hydrogen and oxygen gasses (could create explosing with confinement and a spark) and other things, but these are the most common concerns. Batteries should be close to the charger, and the charger should be close to the electrical power supply (solar panels, windmill or generator to reduce power losses in wire)
I like the Trojan deep cycle batteries. Capacities range from 210 Amp hours to 420+ amp hours. An amp hour is a unit of endurance meaning 1 amp for 1 hour (rated at a maximum current draw. Larger amp-hour batteries have larger capacities. Batteries lose capacity as they age. Given the same power requirements, larger amp-hour batteries will last longer because they will not be discharged as deep.
Lower voltage batteries with higher capacities have better plates. Better to buy lower voltage batteries and put them in series (so voltages add up) than to buy higher voltage batteries and put them in parrallel. Flooded lead-acid batteries are the most common because of lower cost, availablility, efficiency, good charge-holding characteristics, durability and many electronics are built around this system.
You can run one or more battery voltages for your own use. Most people use at least one 12 volt system because of Many people have common 12V appliances. Many people run 12 volt systems and inverters (that convert from lower DC voltage to higher AC household voltages) are cheaper. But running an 18, 24, 36, 48 or 72 volt system will decrease current draw which is easier on your batteries and in many ways safer.
12 volt systems are safe in the sense that (unless you have a deep cut) touching the 12V terminals on a battery will not kill you. There are exceptions of course, but that is general knowledge. There are many 12 volt appliances available and this is why many people have at least one 12 volt power system in their "off the grid" housing. Here are some appliaances: 12 volt inverters (converts 12 Volts DC to 110/120 volts AC), 12 volt coffee makers, 12 volt fridges, 12 volt popcorn poppers, 12 volt DVD players, 12 volt monitors, 12 volt outlets for computer car adapers etc.
The advantage of 24 volt systems is that you have greater voltage and less current. So while your 1000 watt inverter may pull 91 amps at 11 volts on a "12 volt system", then the same setup with 24 volts at 1000 watts is going to draw 45 amps. That's half the current. Power loss through wiring is according to the square of the current times the wiring and connector resistance. Cutting your current in half makes the power loss through wiring one quarter! That's a 75% efficiency gain.
On 24V versus 12 V, since the current draw is half, you can use smaller fuses. Smaller fuses means less spark or ignition heat if you accidently short something out.
On 24V versus 12V, since the current is half, you can use smaller connectors. While a 100 amp connector may run $2.45, a 50 amp connector can run $0.51. All that adds up.
On a "24V system" with four 6V batteries in series, your voltage swing will be greater. While a 12V (two 6 volts in series) will range from 10.5 to 13.8 volts, a "24V system" will range from 21 to 27.6 volts. Sometimes for appliances that run on 12 or 24 volts, this increased voltage can help it run more efficiently.
So, you may say, why not a 48V or 96V system? Well, there are such arrangements. Keep in mind that something over 40 volts on wet skin can shock you. And direct current systems will sting, and contract muscles and not let go! That's one reason why household 110-120V systems use AC or alternating current.
Most appliances are designed for 12V, especially since most vehicles use 12Volts, the devices can be used in a vehicle or with a 12V home system.
The information on this website is for informational purposes only. Use at your own risk. I am not responsible.