Today we’ll discuss 24-volt solar power systems and when it’s good to use a higher voltage battery bank thus, why people do it, as well as some of the benefits and drawbacks of using a higher voltage for an off-grid solar power system battery bank. Thus, Are 24 volts better than 12 volts?
Here are the benefits of a 24 volts better than 12 volts?:
Firstly, you will save money. When building off-grid solar power systems, 24 volt systems are always cheaper. This is because the wire in your system can be expensive, especially if you’re building an extensive system. If you have a 12-volt system, the number of amps going through that wire will be double compared to a 24-volt system. Wire need should be twice as thick to carry that load, and copper wires are not cheap.
The solar charge controller is the following cost. Rated in amps, if you have a 24-volt system, a solar charge controller which is half the size of would be ok on a 12-volt system. So many of these solar charge controllers are rated for 12 and 24 volt systems. A 20 amp controller on a 12-volt system, you can only hook up 260 watts of solar to it.
Another benefit is that all system components like to be at a higher voltage, so if you have high volt solar panels and a higher voltage battery, the solar charge controller has less work to do. Thus, there will be a marginal increase in efficiency with most things at a higher voltage.
You’ll also have less wire loss because wires like to heat up when they carry power. If you’re running at a higher voltage, you’ll have less loss across the wires.
Some of the disadvantages
The first disadvantage is that you need a solar panel array that produces a voltage more significant than the battery bank voltage, which means you can’t use 12-volt solar panels with a 24-volt system. You can use 60-volt solar panels or 100-volt solar panels. You can series connect them as long as you want as long as your solar charge controller can handle it (you can’t use 12-volt solar panels).
The next disadvantage of using a 24-volt system is that you can’t use 12-volt appliances unless you buy a converter. Thus, raising the cost of the system, but it’s still deficient. When purchasing a converter, which costs around $30 to $40, preferably with overcurrent protection and other safety features like temperature control, this is due to 24-volt systems being much cheaper than 12-volt systems. For example, solar charge controllers are much more affordable on a 24-volt system, saving you anywhere from $100 to $400 in that one instance.
DC to DC System (disadvantages continued).
The next disadvantage I mentioned earlier is how difficult it is to find 24-volt equipment locally. If you’re buying all your parts online, it doesn’t matter because you can discover 24-volt stuff just as easily as 12-volt. Still, if you’re sourcing locally, it’s going to be very difficult, so 12 volt is better in that regard.
You can go to the local store and buy an inverter and a deep cycle battery. Never do this because the number of kilowatt-hours you can produce from an alternator at the expense of my charging system is far less than that of a 24V system. People still like to do this even though not efficient at all
If you still want to do this, you must replace your alternator with one designed for charging deeply. Also, if you’re going to do this long term, go to a shop that installs extra alternators and get one created for doing this.
Running a couple of small appliances in 30 to 40 amps
Furthermore, many boat alternators are designed to charge deeply discharged deep cycle batteries for marine applications. Suppose you have an alternator for your car’s charging system and another alternator for 12 or 24 or 48 volts that charges your solar battery.
In this case, it’s a smart move to make because your vehicle’s charging system is designed for only charging the battery of 100-amp hours. It keeps the engine running a couple of small appliances in 30 to 40 amps. I would not charge a solar battery with an alternator unless it had a dedicated alternator. Still, now that we know the advantages and disadvantages of using a 12-volt versus 24-volt battery system. We can discuss the most appropriate time to use a 24-volt battery system.
If you have a small system, 12 volts is OK; if you have a medium-sized system, you should use 24 volts. A 48-volt system is better if you’re building a house system or have it in an off-grid cabin, but 24-volt systems are much safer. With a 12V system, you could place your tongue on that battery, and it would hurt, but you’d be alright. With a 24-volt system, you’ll get a shock, but it’ll be less than 30 volts, so it’s still technically safe.
If you go over 30 volts, things start sparking, and you can get shocked. When you go over 48 volts, you need to know what you’re doing. If you go under 24 volts, you still get some sparks, but they’re not that bad. And I’ve seen many other videos of people shocking themselves like a lecture. So if you have a small system, use 12 volts. If you have a medium-sized or large RV or a tiny home, use 24 volts, and if you have a cabin or a house, use 48 volts.