Got 12 volt should i upgraded to 24 or 48 volt?

I was wondering what the advantages of upgrading to a 24 or 48 volt system? I think I read somewhere that 48 volt uses less to convert so you save more energy in your battery bank is that true?

It depends on your needs.

up to 1500watts, 12 v is fine.
Up to 3000watts, 24v is fine.
There are exceptions, and if you have a HUGE battery bank, larger inverters work at low voltages, but anything over 3000W, and 48v just makes more sense.

It depends on your needs, 12V is simpler and safer to install, but if you have high Watts demand you should use a 24v system or even a 48V system.

I don't think you will be saving money with batteries, a 12v 100AH battery cost almost the same as a 24V 50AH battery and they will produce the same 1000W approx, I think you will be saving money on cables by using greater Voltage systems and you will be able to get larger PV array easier with greater voltage systems. let the experts talk about more specific benefits from it, I'm also interested in this topic.

There doesn't seem to be as much 24V gear out there. I'd go 48V. I don't see any reason to go 24V.

boondox said:

There doesn't seem to be as much 24V gear out there. I'd go 48V. I don't see any reason to go 24V.

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I partially disagree. I would say it depends on your application. I tend to find many more 24v components than 48v. But, my use-case is mobile, so the gear built for marine and mobile applications (where 12v is most common, 24v is semi-common, and >24v is not common) is what I"m most familiar with. But if your application is stationary/residential/or a larger system, I would suspect that 48v is more common than lower voltages. I have found many products available in 12v that I cant find in 24v, but I've yet to find anything available in 48v that I cant find in 24v. Your mileage may vary, as I said, I think its probably application specific, and your experience with 24v probably makes perfect sense in a residential context. Not sure what Op's context is.

There is also the issue of code and safety. In many jurisdictions (including the US) the cutoff point is 50V (48V nominal is over 50V), in many cases this won't matter much, in some cases it will.

Thunderstorm2011 said:

I was wondering what the advantages of upgrading to a 24 or 48 volt system? I think I read somewhere that 48 volt uses less to convert so you save more energy in your battery bank is that true?

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I think this is one of the things, where if you have to ask the question, its almost certainly not worth upgrading your system, if its already functioning adequately.

But getting back to the question:

To understand the main benefit of a higher voltage system, you need to understand three simple equations
Voltage = Current x Resistance (V = I x R)
Power = Voltage x Current (P = I x V)

And derived from the first two we can determine:
Power = Current x Current x Resistance (P = I² x R)

What this means in plain English, is that all other things being equal, if you double the voltage, you halve the current, and you quarter your power losses and voltage drop %. This is a big deal with large systems with big loads and long wire runs, less so with small systems.

Lets imagine a 1200W load, 100ft round trip from your battery bank, 6AWG copper wire. You can use a chart like this to lookup the resistance of the wire which is .04 ohms for 100ft of 6AWG copper wire. So we know P, we know R, and all that's left is I. And because we know P its easy to derive I if we know the system voltage.

Power (loss) = Current² x Resistance
@12v P(loss) = 100² x 0.04 = 400W (33.3%) power loss
@24v P(loss) = 50² x 0.04 = 100W (8.3%) power loss
@48v P(loss) = 25² x 0.04 = 25W (2.1%) power loss

This is an extreme example, but I think it illustrates the principle. For a given load, a higher voltage substantially reduces line loss and voltage drop. If your distances are short, your loads are small, or your wires are properly sized to reduce losses/resistance, this may not be a big deal, and the benefits might be overshadowed by other design considerations.

The other benefit as @JoseAgustinV mentioned is that you can use lower current components which are often cheaper and more readily available. A 50A charge controller can output 600W @ 12v, 1200W @ 24v, or 4800W @ 48v.

And as @boondox mentioned, in some contexts (like large stationary systems) it may be easier to find 48V components.

Dzl said:

I partially disagree. I would say it depends on your application. I tend to find many more 24v components than 48v. But, my use-case is mobile, so the gear built for marine and mobile applications (where 12v is most common, 24v is semi-common, and >24v is not common) is what I"m most familiar with. But if your application is stationary/residential/or a larger system, I would suspect that 48v is more common than lower voltages. mforatbleI have found many products available in 12v that I cant find in 24v, but I've yet to find anything available in 48v that I cant find in 24v. Your mileage may vary, as I said, I think its probably application specific, and your experience with 24v probably makes perfect sense in a residential context. Not sure what Op's context is.

There is also the issue of code and safety. In many jurisdictions (including the US) the cutoff point is 50V (48V nominal is over 50V), in many cases this won't matter much, in some cases it will.

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You may be right, I don't spend much time looking at 24V gear. I still think 48V is the way to go for all of the usual reasons. The higher voltage is OK by me, I work with much higher voltages all the time. Not saying that it isn't an important consideration, just that I am comfortable with the proper protocol for working with HV.

FYI, 48v is not code compliant for ANSI-RVIA. Really no teeth in ANSI-RVIA for the consumer. You won't see a 48v house system on a RVIA certified OEM install.

mapguy525 said:

FYI, 48v is not code compliant for ANSI-RVIA. Really no teeth in ANSI-RVIA for the consumer. You won't see a 48v house system on a RVIA certified OEM install.

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Could you please explain in English what this means?

A quick search will bring it all up. In a nutshell, he is saying that 48V is not considered OK by ANSI in RVs and that no compliant installer will install a 48V system. I must apologize if your intent is to install in an RV, I was speaking of home installation.

RV industry builds to meet NEC, NFPA, and ANSI-RVIA standards. Most RV manufacturers are RVIA members and RVIA certify their products. ANSI-RVIA standards allow 12/24v LV DC systems and 120/240 AC systems. Lots of code compliance language but after the 1st retail sale there is no jurisdictional level compliance mechanism. Thus the standards are un-enforceable for the most part.

RV industry has big pockets -they have successfully avoided most of the mandatory code compliance seen in the building industries by using self regulation.

Thunderstorm2011 said:

I was wondering what the advantages of upgrading to a 24 or 48 volt system?

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This has been answered.

Thunderstorm2011 said:

I think I read somewhere that 48 volt uses less to convert so you save more energy in your battery bank is that true?

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Short answer: No. There are caveats but having 'more energy in your battery' is not a good reason to upgrade.

Thunderstorm2011 said:

I was wondering what the advantages of upgrading to a 24 or 48 volt system? I think I read somewhere that 48 volt uses less to convert so you save more energy in your battery bank is that true?

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48v battery bank needs significantly thinner wiring than 12v.
When you parallel more than two batteries you create imbalances that shorten your battery life significantly.

It's all about the wiring, the wiring determines the Amps, the amps determine the losses in the wiring.
Thick wiring is very expensive.

I would go for 48v if doing a 240v conversion in a heartbeat, I would never consider 24v...never (unless it's a boat or other vehicle)

I have 24v in my boat, makes for cheaper wiring and allows more industrial grade stuff like bilge or water pumps but i also have a couple of 12v step downs for some equipmnet that has easier worldwide availability in a hurry such as lighting, radios etc