DIY Solar 12v vs 24v vs 48v?

We all use batteries in typical day-to-day life. Whether it be in our remote control, watch, car, or RV, batteries are a part of our lives. Most of the time, we don’t need to think about the voltage of a battery. However, when working with DC power systems for RV’s boats or off-grid applications, a serious decision needs to be made between 12V vs 24V vs 48V?

12V DIY Modular Systems

The 12V solar panel is seen as the best option for portable system, motorhomes, caravans, and even boats. Most vehicles use 12V systems as components used in vehicles are designed to operate on 12V. The alternators generate 12V to charge the battery. They will provide just the right amount of power to help keep all of your basic appliances and electrical items running – from phone chargers to fridges and lightbulbs.

In general 12v is good up to max 3000watt. It is a good start for Solar systems since 12v is already in your car or RV. If you are planning on going on holiday and are looking for a versatile solution, then choosing a solar panel system for 12v to help keep everything running off-grid is a perfect solution.

Downsides of 12V

12V systems require massive wires when pulling large loads because the current (amps) are higher. Because 12V batteries use two times the amperage at a given power draw, they are less efficient than a 24V battery due to resistive losses.

24V Modular Systems

The main benefit of a 24 volt system is that you can use smaller diameter wire and reduce amperage by two times. In addition to smaller wires, 24 volt systems operate more efficiently in motors and inverters. Often, the same solar charge controller operating on 24V vs 12V will handle twice the solar input. since many DC MPPT solar charge controllers have higher voltage capabilities to handle higher panel voltages.

They, however, have a hard current limit. Many recommend 24V systems when your power needs are above 3000W or generating 3000W of solar or more. When you get to this point, the benefits of a 24V system outweigh the cons because you can run smaller and increase the system’s efficiency. In general 12v is good up to max 6000watt.

Downsides of 24V

If you are using a 24V system in an application with 12V appliances, you will need a converter to reduce the voltage to 12V. The variety of components and devices that run on 24V are not as plentiful as what is available in 12V. 

48V Modular Systems

The 48V solar system is for larger or permanent off-grid houses and it's considered much safer to run full power appliances more efficiently with fewer amps running through the 48V wiring system to increase power, thus minimizing copper = cut cable cost & better current transmission. The 48 volt system is much more scalable

Basically a 48V system provides the balance between increased capacity without increasing danger.

Downsides of 48V

I you do not have the need for the scalability or the high watt cumsumption it will be a very expensive system.