12 and 24 volt charging systems relate to the way you charge your house batteries, by solar generation, by petrol generator, by mains grid supply, by wind energy, or by all of these methods. We can provide fit or advise on the best ways suitable for your circumstances. It is very important to maintain your batteries at the correct charge criteria for your particular batteries, in order to get good life expectancy from the batteries.
However we also want to charge our Phones, Laptops and Ipads from the house batteries when we are out and about. When charging portable devices that contain their own battery, it is often best to charge them in DC mode.
People often make the mistake of buying cheap inverters to charge their portable devices without realizing the consequences. The conversion from 12 or 24 volt DC to 240 volt AC requires some energy, even when the inverter is on standby. Harvesting solar energy is time dependent, and the idea is to store as much as possible in the batteries, so slow leeks such as those caused by inverters on standby want to be eliminated.